IOMDFCDFM-1
INSTALLATION, OPERATION AND
MAINTENANCE MANUAL FOR DFC & DFM
DIRECT GAS-FIRED HEATERS WITH DDC CONTROLS
ATTENTION: READ THIS MANUAL AND ALL LABELS ATTACHED TO THE UNIT CAREFULLY BEFORE
ATTEMPTING TO INSTALL, OPERATE OR SERVICE THESE UNITS! CHECK UNIT DATA PLATE FOR
TYPE OF GAS AND ELECTRICAL SPECIFICATIONS AND MAKE CERTAIN THAT THESE AGREE WITH
THOSE AT POINT OF INSTALLATION. RETAIN FOR FUTURE REFERENCE.
FOR YOUR SAFETY
The use and storage of gasoline or other flammable vapors and liquids in open
containers in the vicinity of this appliance is hazardous.
POUR VOTRE SÉCURITÉ
L'utilisation et l'entreposage d'essence ou d'autres liquides ou produits émettant des vapeurs
inflammables dans des récipients ouverts à proximité de cet appareil est dangereux.
FOR YOUR SAFETY
If you smell gas:
1. Open Windows
2. Don’t touch electrical switches.
3. Extinguish any open flame.
4. Immediately call your gas supplier.
c
POUR VOTRE SÉCURITÉ
Si vous sentez une odeur de gaz :
1. Ouvrez les fenêtres.
2. Ne pas actionner d'interrupteur.
3. Éteindre toute flamme ouverte.
4. Appelez immédiatement votre
fournisseur de gaz.
WARNING: Improper installation, adjustment, alteration, service or maintenance can
cause property damage, injury or death. Read the installation, operating and maintenance
instructions thoroughly before installing or servicing this equipment.
AVERTISSEMENT : Une installation déficiente, de même qu'un mauvais réglage,
modification, entretien ou maintenance peuvent occasionner des dommages matériels, corporels voire causer la mort. Lire attentivement les instructions d'installation,
d'utilisation et d'entretien avant d'installer ou d'intervenir sur cet appareil.
WARNING
Install, operate and maintain unit in accordance with manufacturer's instructions to avoid
exposure to fuel substances or substances from incomplete combustion which can cause
death or serious illness. The state of California has determined that these substances
may cause cancer, birth defects, or other reproductive harm.
INSTALLER'S RESPONSIBILITY
Installer Please Note: This equipment has been test fired and inspected. It has been shipped
free from defects from our factory. However, during shipment and installation, problems such as
loose wires, leaks or loose fasteners may occur. It is the installer's responsibility to inspect
and correct any problems that may be found.
4830 Transport Drive, Dallas, TX 75247 Phone: 214-638-6010 Fax: 214-905-0806
www.appliedair.com
SECTION I - FOREWARD
Table of Contents
Section I: Foreword, Table of Contents,
and Important Notice .................................. 2
Section II: General Information .................................... 3
Section III: Installation.................................................. 4
Section IV: Pre-Start Up ............................................ 10
Section V: Unit Start Up ............................................. 12
Section VI: Unit Shut Down........................................ 14
Section VII: Troubleshooting Guide ............................ 15
Section VIII: Maintenance Schedule
and Lubrication Requirements............... 34
Section IX: Mestek Burner ......................................... 39
Section X: Manifold and Valve Adjustments............... 40
Section XI: Thermistor Curves ................................... 41
Section XII: Replacement Parts ................................. 42
Section XIII: Recirculating Units ................................ 42
As is the case with any fine piece of equipment, care
must be taken to provide the proper attention to the
operation and maintenance details of this machine.
This manual of instructions along with the Digital
Control System user manual has been prepared in
order for you to become well-acquainted with those
details, and in doing so, you will be able to give your
Direct Gas-Fired System the care and attention which
any piece of equipment needs and deserves.
It is the customer and installation personnel
responsibility to determine if the unit is equipped
with all of the safety devices required for the
particular application. Safety considerations
include the accessibility of the unit to non-service
personnel, the provision of electrical lockout
switches, maintenance procedures and automatic
control sequences. Clearly mark all emergency
shutoff devices.
*IMPORTANCE NOTICE*
Concealed Damage In Transit
Sometimes transit damage is not noticed until the
goods are unpacked. In such cases, notification to
the carrier must be made within fifteen (15) days of
receipt of shipment. In such cases, save the packages
and packing material, then notify the transportation
company at once, and request an inspection. When
the inspector calls, have him make out and leave a
“concealed” bad order report. He is obliged to give one
to you. Insist on it.
Applied Air assumes no responsibility for loss or
damage in transit; therefore, you should protect
yourself by following these instructions:
Bill Of Lading
Save your bill of lading. It is a contract, and you will
need it, provided you have to file a loss or damage
claim. Remember, claims are outlawed after nine
months.
Loss In Transit
Before you sign for this shipment, check against the bill
of lading, also the transportation company’s delivery
ticket. Make sure that you get the exact total of articles
listed. Should the delivery ticket show more or less
items than are offered, then the carrier’s agent must
mark the difference on your freight bill before you sign.
Visible Damage In Transit
If anything is damaged, accept the shipment only if
the carrier’s agent places a notation on your freight
bill explaining the nature and extent of damage. Upon
inspection of article, make claim to the delivering
carrier.
Disposition Of Damaged Articles
Never return damaged articles to us. They are the
property of the transportation company when the claim
is filed. They will give you disposition instructions.
Packing
We comply with the packing requirements of the
transportation companies, and your bill of lading
proved that everything was in good condition when
shipped. That bill of lading contract requires them to
deliver in perfect condition.
–2–
SECTION II - GENERAL INFORMATION
A. Purpose
The purpose of this manual is to present a guide for
proper installation, maintenance, and operation of the
Direct Gas-Fired System, and supplement, but not to
replace, the services of qualified field service personnel to supervise the initial start-up and adjustment
of the unit. Persons without previous experience with
large commercial and industrial heating equipment
should not attempt the initial adjustment and checkout
procedure which is essential before such installations
may be considered ready for operation. This manual
should be made readily available to all operating personnel as an aid in troubleshooting and proper maintenance. Due to the custom nature of this equipment,
not all possibilities are addressed in this manual. The
customer or installer can obtain information from the
local sales representative or by contacting the factory
directly.
WARNING: Failure to comply with general safety
information may result in extensive property damage, severe personal injury or death.
B. Shipping
Base Direct Gas-Fired units are shipped completely
assembled where shipping limitations allow. Optional
inlet hoods, filter and/or damper sections, or other
large accessories are assembled and shipped mounted and wired whenever possible within limitations
of shipping and handling. Any optional accessories
shipped separately are shipped as assembled sections. Any wired accessories which have been disassembled for separate shipment require no additional
conduit or wire for field reassembly. All wire leads will
be tagged for ease of reconnection in the field.
If the unit and/or accessories cannot be installed
immediately, they should be stored in a clean dry
environment. If this is not possible and the unit
must be stored outdoors, it should be protected
from the weather with tarpaulins or plastic
coverings. Do not assume that simply covering a
unit will keep insects, dust and condensation out
of the unit and critical components. Rotate the
fan(s) monthly. Prior to beginning installation of a
unit that has been in storage for weeks or months,
the unit and its components should be closely
inspected.
Shipments are made F.O.B. Dallas, Texas by flatbed truck. The unit is securely strapped, tied, and
blocked to prevent shipping damage. All shipments
are checked by an inspector before they are accepted
by the carrier. Parts that are shipped unmounted are
noted on the bill of lading. These parts, where feasible,
are packaged and shipped with the units. Upon receipt
of shipment, all units should be checked against the
bill of lading to insure all items have been received. All
equipment (and any optional accessories) should be
checked carefully for physical damage in the presence
of the carrier’s representative. If parts are missing or
damage has occurred, a claim should be filed immediately with the carrier.
All Direct Gas-Fired units are given a complete operations test and control circuit checkout before shipment.
Copies of the wiring diagram, piping diagram and
bill of material are included with each unit shipped. If
correspondence with the factory is necessary, please
provide the unit model and serial number.
C. Optional Factory Service
Periodic service on any piece of mechanical equipment is necessary for efficient operation. A nationwide
service support network is available to provide quick
and dependable servicing of make-up air, heating,
ventilating, or air handling types of equipment. Factory
start-up service is also available which includes the
presence of a service engineer to supervise the initial
start-up and adjustment of the equipment and provide
instructions for the owner’s maintenance personnel in
proper operations and maintenance. Consult factory
for quotations on start-up or periodic service.
–3–
SECTION III - INSTALLATION
blower does not rub against blower housing, and that
bearing set screws are tight. If units are not set immediately, cover all openings that might be exposed to the
weather.
FOR CANADIAN INSTALLATIONS ONLY
1. All installations must conform with local building
codes, or, in the absence of local codes, with
current CAN/CGA-B149-Installation Codes For
Gas Burning Appliances and Equipment.
Open the cover on the electrical control box located on
the unit. Inspect all wire terminals and wiring terminations to ensure that all connections are tight.
2. All electrical connections must be in accordance with Canadian Electrical Code, Part 1,
CSA Standard C22.1.
Rotate fans monthly.
All electrical connections must conform to the current
edition of ANSI/NFPA No. 70 National Electrical Code
and applicable local codes; in Canada, to the Canadian Electrical Code, Part 1 CSA Standard C22.1. The
following recommendations are not intended to supplant any requirement of federal, state, or local codes
having jurisdiction. Authorities having jurisdiction
should be consulted before installations are made. Local codes may require additional safety controls and/or
interlocks.
IMPORTANT: Lift and install the modules or sections of a unit separately. Flange connections provided between modules or sections are not structural and damage will occur if any attempt is made
to lift modules that have been flanged together.
See the specification sheet and submittal drawing
for unit or section weight and to determine proper
orientation for each section.
When unloading sections and/or units or moving
equipment to its final location, exercise care to
avoid distortion. Lift sections and/or units only by
the lifting lugs provided and follow the procedures
as outlined below.
All installations in airplane hangers must be in accordance with current ANSI/NFPA No. 409. All installations in public garages must be in accordance with
current NFPA No. 88A and NFPA No. 88B.
CAUTION: Do not install heating system in corrosive
or flammable atmospheres! Premature failure of, or
severe damage to the unit will result!
RIGGING AND MOUNTING DATA - DIRECT FIRED UNITS
CAUTION: Heating system must not be installed in
locations where air for combustion would contain
chlorinated, halogenated or acidic vapors. If located
in such an environment, premature failure of the
unit will occur!
A. Handling the Equipment
As explained previously, the basic unit is designed for
shipping in one piece where shipping limitations allow.
Some optional accessories may require field mounting.
The Direct Gas-Fired unit has been designed for
rigging and handling through the use of special lifting
lugs installed on the top and/or sides of each unit.
When unloading and setting the unit, use the lifting
lugs provided as shown in Drawing #C000539A or
move the equipment on rollers. Hooks, jacks, or chains
must not be used around the casing, main control
panel or exterior mounted controls.
During transit, unloading and setting of the unit, bolts
and nuts may have become loosened, particularly in
the pillow block ball bearing assemblies in the fan section. It is recommended that all nuts and set screws be
tightened. Turn fan shaft by hand to make certain that
–4–
SPREADER
BAR
SPREADER
BAR
A
B
A
B
LIFTING LUGS
PROVIDED IN ONE
OF TWO LOCATIONS
A - USE WHEN LIFTING OVER 3,000 LBS.
B - USE WHEN LIFTING UNDER 3,000 LBS.
08/16/07
C000539A
WARNING: To insure that a proper unit lift is
made, lift unit approximately 24 inches and
verify proper center of gravity lift point. To avoid
dropping of unit, reposition lifting point if unit
is not level. Failure to properly lift unit could
result in death or serious injury or possible
equipment or property-only damage.
B. Locating the Unit
Prior to locating the unit, authorities having jurisdiction should be consulted before installations are made.
Approval permits should be checked against the unit
received.
On Direct Gas-Fired units, which recirculate room air,
outside ventilation air must be provided in accordance
with the information shown on the heater nameplate.
All ventilation air to the heater must be ducted directly
from the outside. See Section XIII.
Use extreme caution in handling the curb. Proper handling and positioning will assure a water-tight curb unit
installation.
Re-check approval prints prior to installation. Be sure
that there are no obstructions to ducting and that
proper planning has been exercised in connection of
piping and/or electrical services.
If in doubt regarding the application of this appliance,
consult the factory.
The curb assembly may be bolted or welded to either
trusses or roof decking; however, connection to roof
trusses is recommended. The curb is designed to carry
the weight of the unit. Additional support is required for
certain applications.
Locate the unit exactly level. Special attention should
be given to the duct, electrical, and fuel connection
points. Install duct work with adequate flexible connections to isolate vibration from the duct work. All duct
work should have taped or caulked seams. Duct work
should be properly sized so as not to inhibit airflow.
This information should be cross-checked with the
position of support beams and stand pipes to insure
that clearance dimensions coincide with those of the
unit. The minimum clearance to combustible material
must be maintained as listed in Table 1.
Placement of the curb is critical in squareness and
leveling. Shims for leveling must be applied to the
curb; application of shims to the unit will tend to
destroy the sealing effect after installation. Make sure
sealing tape is in place before unit is set. Be careful
not to allow gaps where two pieces of sealing tape
meet. A bubble level must be used in the leveling
process. Measure across diagonals to check for
squareness. Allowable tolerance is 1/4" difference
between diagonal measurements. Double-check
approval prints before setting the unit.
Table 1
Minimum clearance to combustible material,
also consult local codes and regulations.
Clearances to Combustible Material
Vertical Units
Horizontal Units
Front*
39 inches
39 inches
Rear
6 inches
6 inches
Right
6 inches
6 inches
Left
6 inches
6 inches
Top
12 inches
12 inches
Floor
Zero
6 inches
*Consider control side as front of unit.
**Optimum clearance for shaft removal would be
equivalent to cabinet width.
Upon completion of setting the curb, apply roofing
material and flashing as required.
Make a visual inspection to insure no damage has occured to the unit during installation.
C. Curb Mounted Units
Outdoor units can be supplied with an optional roof
curb. The curb greatly facilitates installation thereby
reducing installation costs. All connections to the unit:
duct, piping, electrical power and control wiring can
be made through the roof opening. The curb may be
shipped prior to unit shipment. All curbs are shipped
un-assembled from the factory.
D. Location of Accessories
Where applicable, standard or optional accessories will
be placed inside the fan section of the unit for shipment,
and must be removed and installed by the mechanical
or electrical contractor. The inlet hood(s) must be
mounted with a field supplied support. Remotely located
discharge or inlet dampers must be equipped with an
end switch and interlocked to insure maximum design
opening before starting and running circuits may be
energized.
Field constructed intake accessories should be properly
designed to minimize the entry of rain and snow.
Adequate building relief must be provided, so as to not
over-pressurize the building, when the heater is
operating at its rated capacity. This can be accomplished by taking into account, through standard
engineering methods, the structure’s designed infiltration rate, by providing properly sized relief openings,
by interlocking a powered exhaust system, or by a
combination of these methods.
–5–
E. Electrical Connections
F. Field Piping
WARNING: Open all disconnect switches and
secure in that position before wiring unit.
Failure to do so may result in personal injury or
death from electrical shock.
Gas Piping
All gas piping must be in accordance with the requirements outlined in the National Fuel Gas Code - ANSI
Z223.1. It is required that a ground union be installed
adjacent to the manifold for easy servicing. A drip leg
and/or filter should be provided upstream of the unit’s
inlet gas connection. An additional shut-off must be
located external of the unit’s enclosure. The location of
this valve must comply with all local codes. A 1/8 inch
N.P.T. plugged tapping, accessible for test gauge connection, must be installed immediately upstream of the
gas supply connection to the unit.
WARNING: Controls must be protected from
water. Do not allow water to drip on the ignition
system.
NOTE: Before installing any wiring, check the unit
rating plate for supply power rating.
All electrical connections must conform to the current
edition of: ANSI/NFPA No. 70 National Electrical Code
and applicable state and local codes; in Canada, to the
Canadian Electrical Code, Part 1 CSA Standard C22.1
and applicable provincial and local codes.
Since shipment of unit may require disassembly after
factory check and test, reconnection of some electrical
devices will be required in the field. Connect electrical
wires (supplied in factory furnished conduit) to appropriate terminals. All leads are tagged to facilitate field
connections. See wiring diagram provided with equipment. Complete all wiring to any optional accessories
as shown on unit bill of material and electrical wiring
diagram as required before applying voltage to the unit.
WARNING: To avoid equipment damage or
possible personal injury, disconnect gas piping
to this unit until a supply line pressure/leak test
has been completed. Connecting the unit before
completing the pressure/leak test may damage
the unit gas valve and result in a fire hazard.
DANGER: Never use an open flame to detect
gas leaks. Explosive conditions may exist which
would result in personal injury or death.
On vertical units there is a factory installed “Burner
Cleanout” pipe located on the opposite end of the gas
piping compartment. This is a clean out to drain any
condensate that may have collected in the line burner.
If damper actuators require field wiring, make sure the
gasket and cover are securely mounted and assembly
is watertight.
WARNING: DO NOT connect supply gas to this
pipe.
Entry location for all field-installed and control wiring is
through the control panel.
If optional disconnect is not furnished with heater, the
field provided disconnect must be of the proper size
and voltage. Refer to unit rating plate for minimum
circuit ampacity and voltage. The disconnect must be
installed in accordance with Article 430 of the current
edition of ANSI/NFPA No. 70 National Electrical Code.
The gas line should be supported so that no strain
is placed on the unit. Pipe compounds which are not
soluble to liquid petroleum gases should be used on
threaded joints.
Refer to the heater’s rating plate to determine the minimum gas supply pressure required to achieve maximum
gas capacity for the heater.
Check the supply voltage before energizing the unit.
The maximum voltage variation should not exceed
± 10%. Phase voltage unbalance must not exceed 2%.
Une tuyauterie adéquatement dimensionnée doit être
posée jusqu'à l'unité. Veuillez noter que la pression de
la tuyauterie d'alimentation en gaz doit correspondre
à celle spécifiée sur la plaque d'identification, lorsque
l'unité fonctionne à plein rendement.
NOTE: Should any original wire supplied with the
heater have to be replaced, it must be replaced
with wiring material having a temperature rating of
at least 105° C.
Refer to the heater’s rating plate to determine the
maximum supply pressure to the heater.
REMARQUE : Dans le cas où un quelconque des
câbles livrés avec l'unité devait être remplacé, il
doit être remplacé avec des câbles prévus pour
résister à une chaleur d'au moins 105° C.
The appliance and its individual shutoff valve must
be disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures in excess of 1/2 PSIG.
–6–
The appliance must be isolated from the gas supply piping system by closing it’s individual manual shutoff valve
during any pressure testing of the gas supply piping
system at test pressure equal to or less than 1/2 PSIG.
Correctly sized piping must be run to the unit.
Regulator Venting
NOTE: Regulators and devices that have vent limiting
orifices installed do not require a vent line.
a.) Keep the vent line length as short as possible
to minimize the restriction and reduce the vent’s
tendency to cause regulator pulsation .
b.) Never use pipe sizes smaller than the vent size;
smaller pipe sizes restrict the gas flow. If a long gas
vent line length must be used, you should increase
the pipe one nominal size for every ten feet of run
to keep the flow restriction as low as possible.
c.) Support the vent line to eliminate strain on the
regulator diaphragm case.
d.) Always point outdoor vent lines in the downward
position to reduce the possibility of rain, snow,
sleet, and other moisture entering the pipe. Install a
bug screen in the end on the vent line.
e.) Do not locate the vent line terminus near windows,
fans, or other ventilation equipment.
f.) Adhere to all applicable codes and regulations.
g.) If your vent line causes regulator pulsation, consult
your local sales representative or the factory.
h.) We strongly recommend running a separate
vent line for each regulator. Headers with various
installed devices can cause regulator malfunction.
CAUTION: Ensure the vent line is away from ANY
potential ignition sources. It is the installer’s responsibility
to ensure the vent line is exhausting to a safe
environment.
Please note that gas line pressure must be
as shown on specification plate when unit is
operating at full input. The high-pressure regulator
and relief valve should be, if possible, mounted
at least 5 to 10 feet upstream from the appliance
regulator on the unit (if possible).
Building Pressure Transducer Piping (PT-13)
Pipe the high side to location inside the building that
will not be affected by air movement. Pipe the low side
to the atmosphere, positioned so it will not be affected
by the wind and not exposed to the elements. Be sure
that all tubing is clean and clear of any debris before
installing tubes on the transducer.
Flow Station Transducer Piping (PT-15)
Pipe the high side to the upstream connection and
low side to the downstream connection of the Airflow
Station as shown in Drawing # C000643 below. Be
sure that all tubing is clean and clear of any debris
before installing tubes on the transducer.
Refrigerant Piping
Evaporator Coil – Blow Through
The cooling coil section is located in the unit so that
the supply air is blown through the evaporative coil(s).
A properly piped trap should be installed to control
the condensate flow from the unit and also eliminate
conditioned air from being blown out the condensate
drain. See Drawing #C000659B.
Since the condensate is drained by gravity, avoid long
runs of drain piping. If a long run of piping cannot be
avoided or the piping has water flow restrictions, such
as several elbows; add extra height to provide enough
hydrostatic head to overcome the frictional losses.
Always slope piping down a minimum of 1/8” per foot
in the direction of the flow.
On initial start-up, it may be necessary to fill the
trap manually or allow the unit to operate only long
enough for a small amount of condensate to collect in
the drain pan. Then turn off the unit and the trap will
automatically fill.
G. Field Wiring and Remote Control Installation
1. Connect the power lines to the line side of the main
disconnect switch.
2. Mount and wire remote control panel, thermostats,
temperature sensors, and any other field installed
controls as indicated on the unit control wiring diagram.
3. Connect the wires to the appropriate field wiring
terminals as indicated on the unit control wiring diagram.
4. Field wiring shall have a temperature rating of at
least 105°C. The minimum size of the supply cable
circuit shall be sufficient for the maximum ampacity
of the heater.
L'installation éléctrique d'utilisateur aura une
température qui évalue d'au moins 105°C. La
minimum de source du circuit de câblage sera
suffisante pour le ampacity maximum de l'appareil
de chauffage.
H. Locating Temperature Controls
The room or outdoor sensors should be mounted
where they will not be subjected to direct impact of
the heated air or radiant heat from the sun. It is also
recommended that thermostats, especially those with
mercury bulb contacts, be mounted on a vibration free
surface. The side of building columns away from the
heater or interior walls are usually the location best
suited for mounting thermostats.
Controls with outdoor sensors require that the outdoor
sensor be shielded from direct radiation from the sun. Unit
mounted sensors are factory located and mounted.
–7–
SUGGESTED P-TRAP DESIGN FOR CONDENSATE
DRAIN PANS UNDER A POSITIVE PRESSURE
90° LONG RADIUS
PVC ELBOW
NIPPLE
90° LONG RADIUS
PVC ELBOW
J
TO
DRAIN
DRAIN PAN
PVC ADAPTER FITTING
FPT x SLIP
PVC PIPE
NIPPLE
PVC PIPE
NIPPLE
NOTE:
'G' TO BE A MINIMUM OF
1/2" PLUS THE TOTAL SYSTEM
STATIC PRESSURE ("W.C.).
G
'J' TO EXCEED THE POSITIVE
STATIC PRESSURE IN "W.C. OF
THE SECTION OF THE UNIT
WHERE THE DRAIN IS INSTALLED.
PVC RETURN BEND
(10/30/09 C000659B)
DRAIN PLUG
10/30/09 C000659B
AIRFLOW STATION LAYOUT
HEATER
CASING
RA DAMPER
NOTE: RUN TUBE CONNECTIONS
TO TRANSDUCER (PT-15) IN
UNIT CONTROL ENCLOSURE
LOW PRESSURE
TUBE CONNECTION
STATIC PRESSURE
SENSING TUBE
HIGH PRESSURE
TUBE CONNECTION
TOTAL PRESSURE
SENSING TUBE
BULLET
AIRFLOW STATIO N
AMPLIFIER WING
(SHEET METAL STRIP)
EXTERIOR INSULATION
FIELD PROVIDED WHEN
MOUNTED OUTDOORS
C000643
–8–
DIRECTIONS FOR FIELD ASSEMBLING
AND WEATHERPFOOFING SECTIONS
1. Apply gasket material to the end of the first section
(blower, discharge, heater, ets). (See Fig. 1.)
NOTE: One roof cap is attached to a standing
seam on each section for shipping purposes only.
It will be necessary to remove this PRIOR TO SLIDING SECTIONS TOGETHER. Failure to do so may
damage seams, preventing proper seal.
2. Slide adjoining section against the tacky taped first
section. If bolt holes are provided, bolt the sections
together tightly. If bolt holes are not provided, use
furniture clamps to pull sections TIGHTLY together.
Sections, whether bolted or not, will be held together and sealed by the standing seams and hugger
strips (Fig. 2), which will be attached later.
4. Apply caulking material along the top of both sides
of the standing roof seam (Fig.4). Place roof cap
(Fig. 4) on top of the seam and secure it with two
rows of TEK screws (one down each side), spaced
approximately 8-10 inches apart down the entire
length of the seam.
5. Apply two strips of tacky tape (one down each side)
to the back side of each hugger strip (Fig. 2). Secure
hugger strip with two rows of TEK screws (one down
each side) spaced approximately 8-10 inches apart
down the entire length of the seam.
6. After hugger strips are installed, caulk around the
edges to complete the seal.
3. Once the sections are connected, apply caulking or
silicone sealant along the standing roof seam (Fig.
3) and side seams where the sections come together. (Fig.1) It is mandatory to seal the roof and side
seams along the entire outside of the unit, and it is
strongly suggested that the seams also be sealed
along the inside of the unit, if possible.
7. Repeat this process for each section as it is attached. The number of sections varies by application.
NOTE: HOOD REQUIRES ADDITIONAL, INSTALLER
PROVIDED, SUPPORT.
–9–
SECTION IV - PRE START-UP
Do not attempt start-up without completely reading
and understanding this manual, along with the
Digital Control Sysem user manual.
Pre Start-Up
The owners representative or equipment operator
should be present during start-up to receive instructions
on care and adjustments of the equipment.
All equipment has been factory tested, adjusted, metered
and inspected to meet conditions set at the time the
order was placed. Only minimal adjustments should be
required. All information in this service manual is typical.
All products are semi-custom and changes may occur.
CAUTION: Line side of disconnect may be energized.
Follow proper “lockout/tagout” procedures.
NOTE: All servicing and adjustments of the Direct
Gas-Fired unit should be performed by a qualified
service engineer.
Perform a visual inspection, internally and externally,
to make sure no damage has occurred and that everything is secure. This inspection is very important and
should be completed with greatest care given to detail.
A good pre-start inspection will insure against possible
unit damage on start-up and will save valuable analysis time.
1. Check that the physical condition of the unit
exterior is acceptable.
2. Check that the insulation inside of unit is properly
secured.
3. Remove all shipping blocks, brackets and bolts
from supply fan base with optional isolation base.
4. Check all terminals for loose connections and
inspect all wiring terminations to insure that all
crimped connections are tight.
5. Inspect all fan and motor bearings and lubricate if
necessary.
CAUTION: DO NOT RUPTURE GREASE SEALS.
6. Inspect pulleys and belts for tightness, tension and
alignment. Do not overtighten belts.
7. Check set screws on all bearings, pulleys, fans and
couplings for tightness.
8. Check voltage supplied to disconnect switch; the
maximum voltage variation should not exceed ± 10%.
Phase voltage unbalance must not exceed 2%.
9. Check that all relays are securely plugged into the
electronic relay board.
10. Check thermostat(s) for normal operation.
11. Check to ensure all manual reset safety devices
have been reset and limits are in the normal
operating position.
12. Check that system duct work is installed and free
from obstructions.
13. Check that fans turn free in housing.
14. Check that the area around the unit is clear of
flammable vapors or containers of flammable liquids.
15. Check that all piping connections, particularly
unions, are tight. Check all gas piping for leaks
using a soap bubble solution. The most common
types of problems found relative to the gas train
itself is foreign material within the gas piping. This
will interfere with the proper operation of the gas
train components and burner. Purge all air from gas
lines per gas codes.
16. Check that all accessories requiring field wiring
have been properly installed.
17. Check burner for proper location and alignment.
18. Check that filters, filter stops, accessories and ship
loose items are installed correctly.
19. Check that vent lines (if applicable) are run to
atmosphere on gas regulators and pressure
switches for indoor units. Vent lines should
terminate outside the building, with a turndown
elbow and bug screen. Note that some units will use
vent limiters and vent lines are not required. If vent
lines are even partially plugged, this will interfere
with proper venting of pressure control devices.
20. Check that all manual gas shut-off valves are closed.
21. Check that inlet gas pressure is the same as shown
on the rating plate.
22. When failure or malfunction of this heater creates a
hazard to other fuel burning equipment, (e.g. when
the heater provides make-up air to a boiler room),
the heater is to be interlocked to open inlet air
dampers or other such devices.
23. Motor overload relay setting should match the motor’s nameplate full load amperage.
24. Check that dampers and linkages are free to move,
and that linkages are tight.
25. The unit may require that a Return Airflow Station
be field installed. Be sure all tubing connections
are in the correct location as shown in drawing
#C000643.
26. If inlet duct is attached to the heater, a purge
timer must be provided and set to purge 4
times the inlet duct volume.
Purge time in seconds = 4 x L x W x H x 60
SCFM
L = duct length in feet, W = duct width in feet,
H = duct height in feet, SCFM = rating plate air
throughput.
Refer to the electrical schematic for the proper
circuit placement. Purge timer P/N 65.0711.00.
– 10 –
This equipment has been electrically and fire tested
prior to shipment. However, during transit control
setpoints can change, and wiring can come loose. Do
not assume controls are defective until all associated
setpoints and wiring are checked.
If you do not have the optional BACview 6 (KP-01)
keypad display it will be difficult to troubleshoot
any alarm that may occur on the unit. To reset
most alarms on the I/O Zone 583 Controller (UC-01)
without a BACview 6 keypad display, simply turn
the power off and back on at the unit disconnect.
If you have a BACview 6 keypad display the alarm
can be reset remotely or at the I/O Zone 583
Controller.
Suggested Control Settings
(Refer to Digital Control System user manual for default settings)
TS-02
KP-01
MP-05
MP-15
PS-04
PS-07
PS-12
PT-13
FL-02
Space Temperature Sensor...... Customer Discretion
Keypad/Display Module ............ Customer Discretion
Damper Control Potentiometer ... Customer Discretion
Unit Enable Potentiometer ....... Customer Discretion
Low Gas
Pressure Switch ......................................... 1.0" W.C.
High Gas
Pressure Switch ........ 125% above burner firing rate
Clogged Filter Switch ............Adjust to field condition
Building Pressure Transducer... Adjust to field condition
High Temperature Limit (Manual) ................... 185° F
Suggested Tools and Instruments
Volt/Ohm Meter
Thermometer
Tachometer
Ammeter
Manometer (0-10" W.C.)
Microammeter
Standard Hand Tools
D.C. Volt Meter
Gas Pressure Gauge (0-35 lbs.)
BACview 6
BEFORE ATTEMPTING TO START THE HEATER,
READ THE TYPICAL SEQUENCE OF OPERATION
AS SHOWN BELOW:
Typical Sequence of Operations Note: This
sequence is written for only the burner safety and
operating portion of the heater. Other control systems
for dampers, mixing boxes, and temperature controls
are included in the unit typical sequence of operation
and/or wiring diagram:
1. With main supply air fan(s) on, thermostat setpoint
calling for heat, and all switches and operating
controls in their normal position, the heater will go
through a pre-purge sequence. Pre-purge timing is
not adjustable and is approximately 10 seconds.
2. With pre-purge timing complete, the pilot solenoid
valve and ignition transformer are energized. The
pilot flame will be established and sensed by the
flame sensor.
3. Ignition transformer is de-energized and pilot valve
remains on.
4. Main fuel valve(s) will open. The main burner flame
will be established.
5. Once the thermostat is satisfied, the pilot and main
fuel valve(s) will be de-energized. Main supply
fan(s) will continue to run.
Check Safety Shutdown Performace
WARNING: Fire or explosion hazard. Can
cause property damage, severe injury or death.
Perform the safety shutdown test as part
of Start-Up procedure and any time work is
performed on the gas system.
NOTE: Read steps 1 through 7 before starting,
and compare to the safety sutdown or safety
lockout tests recommended for the intermittent
pilot (IP) ignition module. Where diffferent, use the
procedure recommended for the module.
1. Turn off gas supply.
2. Set thermostat or controller above room temperature to call for heat.
3. Watch for ignition spark following prepurge. See IP
module specifications.
4. Time the length of the spark operation. See the IP
module specifications.
5. After the module locks out, open the manual gas
cock and make sure no gas is flowing to the pilot or
main burner.
6. Reset the flame safeguard relay (RE-02).
7. Operate system through one complete cycle to
make sure all controls operate properly.
– 11 –
SECTION V - UNIT START-UP GENERAL
To disable the fans go to “Unit Modes” and enter
[OFF].
Before attempting to start the heater read and
understand the the sequence of operations and
electrical schematic, and the Digital Control
System user manual.
NOTE: A BACview or PC is required to change Unit
Modes. For a more detailed control sequence see
the Digital Control System User Manual.
WARNING: During installation, testing, servicing
and trouble shooting of this product, it may
be necessary to work with live electrical
components. Have a qualified licensed
electrician or other individual who has been
properly trained in handling live electrical
components to perform these tasks. Failure to
follow all electrical safety precautions when
exposed to live electrical components could
result in death or serious injury.
If power supply meets requirements, turn main
disconnect switch on and Enable fans. Damper
opens (if applicable). Blower fan turns on. See
operating modes in Digital Control System user
manual.
Disable the fans. Check supply blower for proper
rotation.
NOTE: To change rotation of the blower, simply
interchange any two (2) of the line leads of the
motor starter for three (3) phase motors. On single
phase motors refer to motor nameplate.
Make sure all manual gas valves are closed.
Make sure all doors and service panels have been
closed or replaced.
Turn main disconnect switch off. Check the incoming
line voltage to match unit rating plate rating. If voltage
is over ±10% of nameplate rating or phase voltage
unbalance is over 2%, notify contractor or power
company.
Fans Are Enabled And Disabled By The Following:
MDT And MRT Standard:
By rotating the remote “Temperature Setpoint” knob
(MP-15).
Clockwise will enable the fans.
Counterclockwise will disable the fans.
MRT-PRO With Smart Room Sensor:
To enable the fans and place the unit in the Occupied
Mode press the “Manual On” button on the face of
the (TS-02) MRT-PRO room sensor. Pressing the
“Warmer” button will add 30-minute increments of
time for a total of 9-hours of operating time. To disable
the fans and place unit in the Unoccupied Mode press
and hold down the “Manual On” button. Alternately
pressing the “Manual On” button will also decrease
the amount of operating time until it reaches zero and
turns the fan off.
MRT Expert or MDT Expert With A BACview (KP-01):
To enable the fans go to “Unit Modes” and enter
[MANUAL], this mode will enable the fans.
To also enable the fans go to “Unit Modes” and enter
[AUTO], this mode has four different functions that
control the fans and unit operation. They are a Time
Clock, Heating and Cooling Night Setbacks, and signal
from an external source to an auxiliary digital input.
Enable the fans. Check for proper blower rpm. Check
that all motor amp draws do not exceed rating plate
ratings and overloads are set to motor rating plate
amps.
Check all dampers for proper operation, and linkage
does not bind, see “Sequence of Operation”, and
Digital Control System user manual for damper control
modes.
Disable the fans.
CAUTION: While performing startup or servicing
the unit when the ambient temperature is warm,
care must be taken not to damage the optional
lube lines on the bearings when the burner is in
high fire.
Setting The Pilot Flame
NOTE: Before attempting to light the pilot and main
burner you need to review Section X for proper
Manifold and Valve Adjustments. A BACview 6 or
PC will be required to change setpoints.
Check the gas supply pressure by replacing the plug
fitting on tthe pilot line with a pressure gauge having
appropriate range, and opening the manual pilot
valve. Check that the pressure reading is within the
specified range on the rating plate.
NOTE: To adjust gas pressure on supply lines
where a regulator has been installed (to reduce the
inlet pressure to rating plate maximum pressure),
remove dust cap of main gas regulator and turn
adjusting screw clockwise to increase pressure or
counter-clockwise to decrease pressure.
– 12 –
Honeywell Flame Safeguard Control
A keyboard display module (Honeywell #S7800A1142)
is recommended to read the flame signal, and is a
good troubleshooting device. A V.O.M. can also be
used on the DC voltage test jacks marked “+” and “-”
on flame amplifier.
Open pilot and first main gas shut-off valves slowly.
Last main gas shut-off valve before burner must
remain closed at this time. Reset high-low gas pressure switches (if applicable). Check pilot and main gas
lines for leaks using soap solution.
NOTE: 3 OR 4 TRIALS MAY BE NEEDED TO
PURGE AIR FROM PILOT LINE. IF BURNER HAS
MAIN FLAME ROD OR SCANNER, YOU WILL NEED
TO DISABLE TIMER CIRCUIT (RE-75).
NOTE: Pilot regulator adjustment may be needed if
the adjustment of the needle valve does not yield
the required reading. Typical adjustment of the
needle valve is 1-1/2 to 2 turns open. Watch D.C.
voltmeter carefully. The reading should be steady
and between 2.0 to 5.0 volts D.C. If the reading is
too low, slowly turn the needle valve in or out until
satisfactory readings are obtained.
Heat is Enabled By The Following:
When pilot is adjusted, shut the burner off by disabling
the fans and heat.
MDT And MRT Standard:
To enable the heat, rotate the “Temperature
Setpoint” knob (MP-15) clockwise to the desired
setpoint above the actual air temperature. The
allowable temperature range is 55o to 90oF.
MRT-PRO With Smart Room Sensor:
To enable the heat, press the “Warmer” or “Cooler”
button on the face of the remote MRT-Pro room sensor
(TS-02) to the desired room setpoint. Each push of the
button changes the temperature setpoint by 1o F. The
setpoint can be changed a maximum of + 10oF from
the default of 65oF. Changing the heating setpoint
also changes the cooling setpoint.
MRT Expert or MDT Expert With A BACview (KP-01):
To enable the heat, scroll through the “Setpoints” menu
in the BACview and enter the desired room Heating
Occupied and Unoccupied Setpoints.
Setting Main Flame
Reconnect power to main flame sensor (RE-75) if
applicable. Install manometer at test port on the last
tee of the burner manifold, or MR valve test port. Make
sure the Run/Test switch on (RE-02) is in the run
position.
Slowly open all manual gas shut-off valves.
Enable fan and heat. After “pilot proven”, main gas
valve opens and burner lights.
Adjust high fire pressure reading (from manometer) to
match Normal Manifold Pressure firing rate shown on
unit rating plate. Take care not to damage optional lube
lines.
Refer to Valve Adjustment instructions in Section X
for setting high and low fire gas pressure settings.
Energy Savings Modes:
There are 3 Energy Savings Modes that could
disable the burner.
The high fire setting must be made before adjusting
low fire. Adjust the high fire setting according to the
Maxitrol Valve Adjustment instructions in Section X.
The high fire setting must not exceed the pressure
stated on the rating plate.
NOTE: A BACview or PC is required to change
Setpoints. For a more detailed control sequence,
see the Digital Control System Users Manual.
When adjusting low fire, there should be a
continuous flame along the entire burner length
without any blowout spots. Main burner flame
sensor must be activated, if applicable. Burner must
hold in low fire for approximately 10 seconds before
modulating up.
Enable the fans and burner, then reset burner relay
(RE-02).
Unit will run for 10 seconds before ignition trial, if all
safety and limits are made.
NOTE: Do not leave the Run/Test switch on the
flame safeguard relay (RE-02) in the test position
during (PFEP) for more than 60 seconds. This will
cause the control program to go into a Burner
Status Alarm. This alarm can be reset by recycling
power to the unit.
CAUTION: You will have approximately three (3)
minutes before the unit shuts down on Freezestat
(Low Discharge Temperature), if you have
disconnected plug wires TS-01 and TS-03. Referred
to in Section X.
Check flame signal with burner cycling through full firing
range and burner profile damper operation (if applicable).
Cycle pilot and burner several times to insure smooth
light off.
There should be a continuous spark for ten (10)
seconds with pilot gas supply turned off.
Check pilot and main gas lines for leaks.
Main flame is now set. Make sure burner modulates
and turn thermostat to the desired setting.
– 13 –
Safety Controls Check All
A. Flame Safeguard – Close last manual gas valve
before main burner. Operate unit in Heat mode. After
pilot flame has been established, close manual pilot
gas valve. The flame safeguard must trip out within 15
seconds. (See Safety Shutdown Performance on page
10.
Cooling is Enabled By The Following:
B. Firestats – These limit controls are not adjustable
and are checked at the factory. Reset the red button(s)
to be sure they are ready for operation. Contact factory
if these switches fail to reset.
MRT-PRO With Smart Room Sensor:
To enable the cooling, press the “Warmer” or
“Cooler” button on the face of the remote MRT-Pro
room sensor (TS-02) to the desired room setpoint.
Each push of the button changes the temperature
setpoint by 1o F. The setpoint can be changed a
maximum of + 10oF from the default of 73oF. Changing
the cooling setpoint also changes the heating
setpoint.
C. Gas Pressure Switches – The low pressure switch
will trip out and must be reset before resuming operation when the inlet gas valve is turned off during operation. The high pressure switch may be checked out by
reducing the setting of its trip point to unit operating
pressure. It should then trip out and shut off the burner.
Return the adjustment to its original setting and reset
to resume operation.
D. Air Pressure Switches – The high air pressure
switch is checked by removing the sensing tube from
the entering air side of the burner and gently blow into
the switch connection. Switch operation will shut off the
burner. Recycle is automatic when the sensing tube
is replaced. The low air pressure switch is checked by
removing the sensing tube from the leaving air side of
the burner. Switch operation will shut off the burner.
Recycle is automatic when the sensing tube
is replaced.
MDT And MRT Standard:
To enable the cooling, rotate the “Temperature
Setpoint” knob (MP-15) clockwise to the desired
setpoint below the actual air temperature. The
allowable temperature range is 55o to 90oF.
MRT Expert or MDT Expert With A BACview (KP-01):
To enable the cooling, scroll through the “Setpoints”
menu in the BACview and enter the desired room
Cooling Occupied and Unoccupied Setpoints.
Energy Savings Mode:
Energy Savings Mode 4 can disable the cooling.
NOTE: The cooling outputs are protected by an
anti-cycle timer which has a 3 minute off/3 minute
on delay. A BACview or PC is required to change
Setpoints. For a more detailed control sequence,
see the Digital Control User Manual.
E. Adjustable Temperature and Limit Controls – The
limit controls are checked by adjusting control settings
to a lower temperature setting while the unit is operating on high fire and observing cutoff. The controls
should be reset to settings shown below:
SECTION VI - UNIT SHUTDOWN
A. Extended Shutdown —
1. Disable the heating and cooling for 30 seconds,
then disable the fan.
2. Close all manual gas valves.
3. Open the main electrical disconnect switch.
4. If the unit is to remain idle for an extended period,
the blower and motor shafts should be rotated by
hand to spread the grease over the bearings.
B. Emergency Shutdown ONLY —
1. Open the main electrical disconnect switch.
2. Close the main manual gas valve.
– 14 –
SECTION VII - TROUBLE SHOOTING
HONEYWELL RM7897A1002, RM7897C1000
7800 SERIES RELAY MODULES
PRINCIPAL TECHNICAL FEATURES
The RM7897 provides all customary flame safeguard
functions as well as significant advancements in safety,
annunciation, and system diagnostics.
Safety Shutdown (Lockout) Occurs if:
1. INITIATE PERIOD
a. Purge card is not installed or removed.
b. Purge card is bad.
c. Configuration jumpers have been changed (after
200 hours) - Fault Code 110.
d. AC line power errors occurred, see Operation.
e. Four minute INITIATE period has been
exceeded.
2. STANDBY PERIOD
a. Airflow lockout feature is enabled and the airflow
switch does not close after ten seconds or within
the specified purge card timing.
b. Flame signal is detected after 240 seconds.
c. Ignition/pilot valve terminal is energized.
d. Main valve terminal is energized.
e. Delayed main valve terminal is energized
(RM7897C).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
i. Preignition Interlock open.
3. PREPURGE PERIOD
a. Airflow lockout feature is enabled and the airflow
switch opens.
b. Ignition/pilot valve terminal is energized.
c. Main valve terminal is energized.
d. Delayed main valve terminal is energized
(RM7897C).
e. Internal system fault occurred.
f. Purge card is removed.
g. Purge card is bad.
h. Flame signal is detected for 30 seconds.
i. Preignition interlocks open durning stand by.
4. PILOT FLAME ESTABLISHING PERIOD (PFEP)
a. Airflow lockout feature is enabled and the airflow
switch opens.
b. No flame signal at end of PFEP.
c. Ignition/pilot valve/intermittent pilot valve
terminal is not energized.
d. Main valve terminal is energized (RM7897A).
e. Delayed (second stage) main valve terminal is
energized (RM7897C).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
5. MAIN FLAME ESTABLISHING PERIOD (MFEP)
(RM7897A, teminal 21)
a. Airflow lockout feature is enabled and the airflow
switch opens.
b. Ignition terminal is energized.
c. Ignition/pilot valve terminal is not energized.
d. Main valve terminal is not energized.
e. Delayed main valve terminal is energized.
f. Loss of flame signal
g. Internal system fault occurred.
h. Purge card is removed.
i. Purge card is bad.
6. RUN PERIOD
a. No flame present (JR2 removed).
b. Airflow lockout feature is enabled and the airflow
switch opens.
c. Interrupted pilot valve terminal is energized
(RM7897A, terminal 21).
d. Main valve terminal is not energized.
e. Delayed main valve terminal is not energized
(RM7897C).
f. Internal system fault occurred.
g. Purge card is removed.
h. Purge card is bad.
i. Ignition terminal is energized.
OPERATION
Sequence of Operation
The RM7897A has the operating sequences listed
below; see Fig. 5 and 6. The RM7897A LED provide
positive visual indication of the program sequence:
POWER, PILOT, FLAME, MAIN and ALARM.
Initiate
The RM7897A Relay Module enters the INITIATE
sequence when the relay module is powered. The
RM7897A can also enter the INITIATE sequence if the
relay module verifies voltage fluctuations of +10/-15%
or frequency fluctuations of ±10% during any part
of the operating sequence. The INITIATE sequence
lasts for ten seconds unless the voltage or frequency
tolerances are not met. When not met, a hold condition
is initiated and displayed on the optional KDM for at
least five seconds; when met, the INITIATE sequence
restarts. If the condition is not corrected and the hold
condition exists for four minutes, the RM7897A locks
out.
– 15 –
SECTION VII - TROUBLE SHOOTING continued
Causes for hold conditions in the INITIATE sequence:
1. AC line dropout detection.
2. AC line noise that can prevent a sufficient reading
of the line voltage inputs.
3. Low line voltage brownouts.
The INITIATE sequence also delays the burner motor
starter from being energized and de-energized from an
intermittent AC line input or control input.
Standby
The RM7897A is ready to start an operating sequence
when the operating control input determines a call for
heat is present. The burner switch, limits, operating
limit control and all microcomputer-monitored circuits
must be in the correct state for the relay module to
continue into the PREPURGE sequence.
Normal Start-Up Prepurge
The RM7897A Relay Module provides PREPURGE
timing selectable from two seconds to thirty minutes
with power applied and the operating control indicating
a call for heat.
1. The Airflow Interlock, burner switch, Run/Test
switch and all microcomputer-monitored circuits
must also be in the correct operating state.
2. The motor output, terminal 4, is powered to start
the PREPURGE sequence.
3. The Airflow Interlock input closes ten seconds into
PREPURGE or within the specified purge card
timing; otherwise, a recycle to the beginning of
PREPURGE or lockout occurs, depending on how
the Airflow Switch selectable jumper (JR3) is configured.
Ignition Trials
1. Pilot Flame Establishing Period (PFEP):
a. When the PFEP begins:
(1) The pilot valve and ignition transformer,
terminal 21 is energized. The RM7897A has
an intermittent pilot valve, terminal 8 and
interrupted pilot valve, terminal 21.
(2) Flame must be proven by the end of the ten
second PFEP (four seconds if Configuration
Jumper JR1 is clipped) to allow the
sequence to continue. If a flame is not
proven by the end of PFEP, a safety shutdown occurs.
(3) The pre-ignition interlock is ignored
throughtout the trial for ignition state.
2. Main Flame Establishing Period (MFEP):
a. After PFEP, and with the presence of flame,
the main fuel valve, terminal 9, is powered. If a
flameout occurs, the relay module locks out or
recycles (depending on status of jumper JR2)
within 0.8 or 3 seconds, depending on the Flame
Failure Response Time (FFRT) of the amplifier.
b. The RM7897A (terminal 21) has a ten second
MFEP. After the Ignition Trials, the interupted
pilot valve, terminal 8 is de-energized. If a
flameout occurs, the relay module locks out or
recycles (depending on status of jumper JR2)
within 0.8 or 3 seconds, depending on the
amplifier FFRT.
Run
1. The RM7897C has a delayed main valve that is
energized once the RUN period is entered.
2. The relay module is now in RUN and remains in
RUN until the controller input, terminal 6, opens,
indicating that the demand is satisfied or a limit has
opened.
Post Purge
After demand is satisfied or a limit opens,
de-energizing terminal 6, the Ignition/Pilot valve,
main valve and delayed main valve, terminals 8, 9,
and 21 are de-energized. The blower motor, terminal
4, remains powered during the specified programmed
time. The Pre-Ignition Interlock closes within the first
five seconds of Post Purge.
Run/Test Switch
The Run/Test Switch is located on the top side of the
relay module, see Fig. 4. The Run/Test Switch allows
the burner sequence to be altered as follows:
1. In the measured PREPURGE sequence, the Run/
Test Switch, placed in the TEST position, causes
the PREPURGE timing to stop.
2. In the Pilot Flame Establishing Period, the Run/Test
Switch, placed in the TEST position, stops the
timer during the first eight seconds of a ten-second
PFEP selection or during the first three seconds
of a four-second PFEP selection. It allows for pilot
turn-down test and other burner adjustments. This
activates a fifteen-second flameout timer that permits pilot flame adjustment without nuisance safety
shutdowns. The Run/Test Switch is ignored during
PFEP for the C relay module if terminals 8 and 9 or
9 and 21 are jumpered.
IMPORTANT: When the relay module is switched to
the TEST mode, it stops and holds at the next Run/
Test Switch point in the operating sequence. Make
sure that the Run/Test Switch is in the RUN position
before leaving the installation.
– 16 –
SECTION VII - TROUBLE SHOOTING continued
SETTINGS AND ADJUSTMENTS
Selectable Site-Configurable Jumpers
The relay module has three site-configurable jumper
options, see Fig. 6 and Table 7. If necessary, clip the
site-configurable jumpers with side cutters and remove
the resistors from the relay module.
Figure 6 - Selectable Site-Configurable Jumpers
SELECTABLE CONFIGURATION JUMPERS
RUN/TEST SWITCH
(EC7895C; RM7895C,D; RM7896C,D)
SERVICE NOTE: Clipping and removing a site-configurable jumper enhances the level of safety.
Figure 5 - Sequence Status LEDs
RUN/TEST SWITCH
(RM7895C,D;
EC7895C;
RM7896C,D)
CAPTIVE
MOUNTING
SCREW
PLUG-IN
PURGE
CARD
M7553A
DUST
COVER
SEQUENCE
STATUS
LEDs
Table 7 - Site-Configurable Jumper Options
RELAY
MODULE
RESET
PUSHBUTTON
Jumper
Number
FLAME
AMPLIFIER
FLAME
SIMULATOR INPUT
FLAME CURRENT
TEST JACKS
M7552A
Description
Intact
Clipped
JR1*
Pilot Flame
Establishing Period (PFEP)
10 Seconds
4 Seconds
JR2
Flame Failure Action
Recycle
Lockout
JR3
Airflow Switch (ILK)
Failure
Recycle
Lockout
IMPORTANT: Clipping and removing a jumper after
200 hours of operation causes a nonresettable Fault
110. The relay module must then be replaced.
WIRING
SUBBASE
RUN/TEST (C,D ONLY)
SWITCH
HONEYWELL
RELAY
MODULE
CONFIGURATION
JUMPERS
PURGE
TIMER
SEQUENCE
STATUS
LED PANEL
POWER
RESET
BUTTON
PILOT
FLAME
MAIN
ALARM
KEYBOARD
DISPLAY
MODULE
RESET
BURNER CONTR
EDIT:
_
+
OL
CAPTIVE
MOUNTING
SCREW
FLAME
AMPLIFIER
BACK
- ENTER -
M22827
Figure 4 - RM7897A,C Relay Module Exploded View
– 17 –
SECTION VII - TROUBLE SHOOTING continued
Figure 2 - Wiring Subbase and Sequence Chart for RM7897A
Q7800
FOR DIRECT SPARK IGNITION
(OIL OR GAS)
G
12
L2
13
10
IGNITION
TRANSFORMER
LINE VOLTAGE ALARM
3
14
8
MAIN VALVE
BURNER MOTOR
(BLOWER)
4
15
5 (L1)
16
BURNER
CONTROLLER/LIMITS
6
17
RUNNING INTERLOCK
(INCLUDING
AIRFLOW SWITCH)
7
18
INTERMITTENT
PILOT/IGNITION
8
19
MAIN FUEL VALVE(S)
9
20
10
21
F
22
2
IGNITION
FLAME DETECTOR
PREIGNITION
INTERLOCK
10-SECOND
INTERRUPTED
PILOT
MASTER
SWITCH
L1
(HOT)
3
POWER
LED
DISPLAY
BURNER
1
L2
INITIATE
(INITIAL
POWERUP
ONLY)
L2
PFEP
5
00
10 SEC.
00(4 SEC. IF 10
TIMED
PREPURGE
JR1 CLIPPED
STANDBY
MFEP
POWER
00
20
4
POSTPURGE STANDBY
RUN
POWER
POWER
POWER
POWER
PILOT
PILOT
PILOT
PILOT
FLAME
FLAME
FLAME
FLAME
MAIN
MAIN
MAIN
MAIN
ALARM
ALARM
ALARM
ALARM
BURNER/BLOWER MOTOR
10
POWER
POWER
5
IGN.
INTERMITTENT PILOT
8
21
INTERRUPTED PILOT 21
MAIN VALVE
OPERATING
CONTROLS
AND
INTERLOCKS
LIMITS AND BURNER CONTROLLER CLOSED L1 TO 6
RUNNING INTERLOCKS CLOSED 6 TO 7
PREIGNITION INTERLOCK CLOSED
FLAME
SIGNAL
5 TO 20
PII
SAFE START CHECK
FLAME PROVING
1 120 VAC, 50/60 HZ POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
2
9
DO NOT CONNECT ANY WIRES TO UNUSED TERMINALS.
SSC
3
SEE FLAME DETECTOR SPECIFICATIONS FOR CORRECT WIRING.
4
PROGRAMMED ON SETUP USING S7800A1142 DISPLAY.
5
PURGE TIME DEPENDS ON WHICH ST7800 IS INSTALLED.
M22728B
– 18 –
SECTION VII - TROUBLE SHOOTING continued
The POWER LED provides fault identification when the Relay Module locks out on an alarm. Fault identification is
a series of fast- and slow-blinking LED lights. The fast blinks identify the tens portion of the fault code (three fast
blinks is 30), while the slow blinks identify the units portion of the fault code (two slow blinks is 2). Three fast blinks
followed by two slow blinks would be fault code 32. This identifies a running interlock on during STANDBY. (See
following Table for Blinking Fault Code List.)
The LED code repeats as long as the fault exists. To clear the fault, press the RESET button.
Blinking Fault Codes and Recommended Troubleshooting
Fault Code
System Failure
Recommended Troubleshooting
Code 1-1
*Low AC Line
Voltage*
Low AC Line detected.
1.
2.
3.
Code 1-2
*AC Quality
Problem*
Excessive noise or
device running on slow,
fast, or AC line dropout
detected.
4.
Check the relay module and display module connections.
Reset and sequence the Relay Module.
Check the 7800 power supply and make sure that frequency and voltage meet
specifications.
Check the backup power supply, as appropriate.
Code 2-1
*Unexpected
Flame Signal*
Flame sensed when no
flame is expected during
STANDBY or PURGE.
1.
2.
3.
4.
5.
6.
7.
Check that flame is not present in the combustion chamber; correct any errors.
Make sure that the flame amplifier and flame detector are compatible.
Check the wiring and correct any errors.
Remove the flame amplifier and inspect its connections. Reseat the amplifier.
Reset and sequence the relay module.
If the code reappears, replace the flame amplifier and/or the flame detector.
If the fault persists, replace the relay module.
Code 2-2
*Flame Signal
Absent*
No-flame time present
at the end of the PIlot
Flame Establishing
Period; lost during the
Main Flame Establishing
Period or during RUN.
1.
2.
3.
4.
Measure the flame signal. If one exists, verify that it meets specifications.
Make sure that the flame amplifier and flame detector are compatible.
Inspect the main fuel valve(s) and valve connection(s).
Verify that the fuel pressure is sufficient to supply fuel to the combustion chamber.
Inspect the connections to the fuel pressure switches. Make sure they are
functioning properly.
Inspect the Airflow Switch and make sure that it is functioning properly.
Check the flame detector sighting position; reset and recycle. Measure the flame
signal strength. Verify that it meets specifications. If not, refer to the flame detector
and/or flame amplifier checkout procedures in the installation instructions.
Replace the flame amplifier and/or the flame detector, if necessary.
If the fault persists, replace the relay module.
5.
6.
7.
8.
Code 2-3
*Flame Signal
Overrange*
Flame signal value is
too high to be valid.
1.
2.
3.
4.
5.
6.
Code 3-1
*Running/
Interlock Switch
Problem*
Running or Lockout
Interlock fault during
Prepurge.
1.
2.
3.
4.
5.
Make sure the flame detector and flame amplifier are compatible.
Remove the flame amplifier and inspect its connections. Reset the flame amplifier.
Reset and sequence the relay module.
Check the flame detector sighting position; reset and recycle. Measure flame
strength. Verify that it meets specifications. If not, refer to the flame detector
and/or flame amplifier checkout procedures in the installation instructions.
If the code reappears, replace the flame amplifier and/or the flame detector.
If the fault persists, replace the relay module.
Check wiring; correct any errors.
Inspect the fan; make sure there is no air intake blockage and that it is supplying air.
Make sure the Lockout Interlock switches are functioning properly and the contacts
are free from contaminants.
Reset and sequence the relay module to Prepurge (place the TEST/RUN Switch
in the TEST position, if available). Measure the voltage between terminal 7 and G
(ground); 120 Vac should be present. Switch TEST/RUN back to RUN.
If steps 1 through 4 are correct and the fault persists, replace the relay module.
– 19 –
Blinking Fault Codes and Recommended Troubleshooting
Fault Code
Code 3-2
*Running/
Interlock On
During
Standby*
System Failure
Lockout Interlock
powered at improper
point in sequence or On
in Standby.
Recommended Troubleshooting
1.
2.
3.
4.
5.
Code 3-3
*VPS in
Improper State*
VPS (Valve Proving
Switch) in wrong state
during VPS Test.
1.
2.
3.
4.
5.
Code 4-1
*Purge Card
Problem*
Code 4-2
*Wiring
Problem/
Internal Fault*
No purge card or the
purge card timing has
changed from the
original configuration.
Pilot (ignition) valve
terminal, main valve,
ignition or Main Valve 2
was on when it should
be off.
1.
2.
Check wiring to make sure that the Lockout Interlocks are connected properly
between terminals 6 and 7. Correct any errors.
Reset and sequence the relay module.
If the fault persists, measure the voltage between terminal 6 and G (ground), then
between terminal 7 and G. If there is 120 Vac at terminal 6 when the controller is off,
the controller switch may be bad or is jumpered.
If steps 1 through 3 are correct and there is 120 Vac at terminal 7 when the
controller is closed and the fault persists, check for a welded or jumpered Running
Interlock or Airflow Switch. Correct any errors.
If steps 1 through 4 are correct and the fault persists, replace the relay module.
Check wiring, making sure upstream valve is connected to terminal 9 and
downstream valve is connected to terminal 17.
Conduct Valve Seat leakage test using a manometer.
Reset and sequence the relay module; if fault repeats, test VPS (connected to
terminal 16) is functioning properly; replace if necessary.
Reset and sequence the relay module.
If fault persists, replace the relay module.
3.
4.
5.
6.
Make sure the purge card is seated properly.
Inspect the purge card and the connector on the relay module for any damage or
contaminants.
Reset and sequence the relay module.
If the fault code reappears, replace the purge card.
Reset and sequence the relay module.
If the fault code persists, replace the relay module.
1.
2.
3.
4.
5.
WARNING
Electrical Shock Hazard; Fire or Explosion Hazard.
Can cause severe injury, death or property damage.
Remove system power and turn off power supply.
Remove system power and turn off fuel supply.
Check wiring; correct any errors.
inspect Pilot Fuel Valve(s), both places, and connections.
Reset and sequence the relay module.
If the fault persists, replace the relay module.
Code 4-3
*Flame
Amplifier
Problem*
Flame not sensed, or
sensed when it should
be on or off.
1.
2.
3.
4.
5.
6.
Check wiring; correct any errors.
Make sure the flame amplifier and flame detector are compatible.
Remove the flame amplifier and inspect the connections. Reseat the amplifier.
Reset and sequence the relay module.
If the code reappears, replace the flame amplifier and/or the flame detector.
If the fault persists, replace the relay module.
Code 4-4
*Configuration
Jumper
Problem*
The configuration
jumpers differ from the
sample taken at startup.
1.
2.
3.
Inspect the jumper connections. Make sure the clipped jumpers were completely
removed.
Reset and sequence the relay module.
If the fault persists, replace the relay module.
Code 5-1
*Preignition
Interlock*
Preignition Interlock
fault.
1.
2.
3.
4.
5.
Check wiring and correct any errors.
Check Preignition Interlock switches to assure proper functioning.
Check fuel valve operation.
Reset and sequence the relay module; monitor the Preignition Interlock status.
If the fault persists, replace the relay module.
Code 5-2
*High Fire Sw.
or Low Fire
Sw.*
Either High Fire Switch
or Low Fire Switch
failure.
1.
2.
3.
Check wiring and correct any errors.
Reset and sequence the relay module.
Use manual motor potentiometer to drive the motor open and closed. Verify at
motor switch that the end switches are operating properly. Use RUN/TEST switch if
manual potentiometer is not available.
Reset and sequence the relay module.
If the fault persists, replace the relay module.
4.
5.
– 20 –
Blinking Fault Codes and Recommended Troubleshooting
Fault Code
System Failure
Recommended Troubleshooting
Code 5-3
*Man-Open
Sw.; Start Sw.
or Control On*
Man-Open Switch, Start
Switch or Control On in
the wrong operational
state.
1.
2.
Code 6-1
*Internal Faults*
Relay Module self-test
failure.
1.
2.
3.
4.
5.
3.
Code 6-2
*Internal Faults*
Relay Module Self-Test
failure.
1.
2.
3.
4.
Code 6-3
*Device
Specific*
Fault with special OEM
input circuits.
1.
2.
3.
4.
5.
Code 6-4
*Accessory
Fault*
Unused at this time.
—
Code 7-7
*Unused*
Unused at this time.
—
Check wiring and correct any errors.
Make sure that the Manual Open Valve Switch, Start Switch and Control are
operating properly.
Stat Switch held ìOnî too long.
Reset and sequence the relay module.
Reset and sequence the relay module. If the fault persists, replace the relay module
(RM7838A1014; RM7838B1013 or RM7838C1004 only).
Reset and sequence the relay module.
If fault reappears, remove power from the device, reapply power, then reset and
sequence the relay module.
If the fault persists, replace the relay module.
Reset and sequence the relay module.
If fault reappears, remove power from the device, reapply power, then reset and
sequence the relay module.
If fault does not repeat on the next cycle, check for electrical noise being copied
into the relay module through the external loads or possibly an electrical grounding
issue.
If the fault persists, replace the relay module.
Check wiring and operation of special OEM inputs.
Reset and sequence the relay module.
If fault reappears, remove power from the device, reapply power, then reset and
sequence the relay module.
If the fault does not repeat on the next cycle, check for electrical noise being copied
into the relay module through the external loads or possibly an electrical grounding
issue.
If the fault persists, replace the relay module.
The following is a simplified list of possible problems
and typical causes and remedies. However, it does
not cover all possibilities, and is intended as a guide
only. You might also need to reference the Digital
Control System User Manual for additional troubleshooting and diagnostics.
WARNING: Many of the steps listed on the
following pages require electrical cabinet and
blower access while the unit is powered. High
voltage and moving parts are present, and these
steps should be performed by qualified service
personnel. If any of the controls requiring
manual reset were at fault this is an indication
of a problem with the system that should be
investigated.
– 21 –
SECTION VII - TROUBLESHOOTING continued
Fan and Heat Mode
Symptom
A. Blower does not operate.
B. No voltage at flame
safeguard relay (RE-02)
input terminal and the
fan is enabled.
Cause
Remedy
1. Check power source.
2. Check and replace.
3. Close or connect customer interlock.
4. Enable the fan.
5. Check time clock, night setback
thermostat and field installed controls for proper settings.
6. Reset freeze stat by interrupting
power. Check for proper setpoint
and burner operation.
7. See Digital Control System User
7. DO-1 on UC-01 not energized.
Manual.
8. Check power source and/or re
8. RE-57 contacts open.
place.
9. Check for power at damper motor
9. Damper motor not operating,
and that end switch has been wired
its end switch not making, or the
correctly to the N.O. (normally
damper is binding.
open) contact. Check that the linkage is clear and not binding.
10. Push reset button on starter and
10. Overload Protection on motor
check amps.
starter tripped.
11. Turn off power and check belts.
11. Belts loose or broken.
12. Check and/or replace.
12. Bearings seized.
13. Motor may be burned or incorrectly 13. Turn off power and check motor
and wiring.
wired.
14. Check burner firing rate.
14. Motor overheating.
1. Low or no voltage.
2. Circuit breaker open.
3. Customer interlock not closed or
connected.
4. Fan is disabled.
5. Time clock, night setback
thermostat, or field installed
controls open.
6. Freeze protection tripped. (low
discharge temeprature)
1. Heat mode is disabled.
2. Auxiliary switch on starter not
closed (ST-01).
3. Air flow switches open.
4. Outside air temperature higher
than Heating Economizer Setpoint.
5. DO-2 or RE-28 not energized.
6. RE-27, 56, or 65 contacts open.
7. High temperature limit thermostat
open.
1. Enable the heating mode.
2. Check auxiliary circuit wiring and
contact.
3. Adjust the air flow and external
static pressure to match the rating
plate (Do not adjust switch setpoint).
4. Check setpoint for proper setting.
5. See Digital Control System User
Manual.
6. See Multiplexed Voltage Value Chart.
7. Reset control and correct problem
before restarting.
8. Check gas pressure and reset
8. High-low gas pressure switch
switch.
open (if applicable).
9. Check for power, replace if
9. Field supplied purge timer open (if
necessary.
applicable).
C. Flame safeguard relay
(RE-02) goes into safety
shutdown (lockout).
1. See technical cut sheet on flame
safeguard relay.
1. Determine the cause of (lockout).
Push reset button on flame
safeguard relay.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
– 22 –
SECTION VII - TROUBLESHOOTING continued
Heat Mode continued
Symptom
D. Pilot does not light after
prepurge has timed
out (10 seconds) and
voltage is present on
flame safeguard output
terminals.
Cause
1. Manual pilot shut-off valve closed.
2. Inlet gas pressure lower than
required gas pressure
3. No gas through pilot regulator
with inlet gas pressure ok.
4. No gas through pilot solenoid.
5. Type of gas (natural - LP)
supplied different from factory
required type. Note: components
may change.
6. Flame detection system not
sparking or sensing pilot flame.
(See spark rod diagram in
Section IX.)
7. No voltage on secondary side of
ignition transformer.
E. Pilot does not light after
prepurge has timed out
and there is no voltage
at flame safeguard relay
output terminals.
1. Flame safeguard relay Run/
Test switch in Test position or
functioning problem.
F.
1. Manual gas shut-off valve closed.
No heat with pilot ok
and voltage is present
at flame safeguard relay
output terminals.
2. No gas on outlet side of
regualtors with inlet pressure ok.
3. No gas on outlet side of valve or
actuator with inlet pressure ok.
4. Main flame rod or scanner not
sensing main burner.
5. RE-75 energized
Remedy
1. Slowly open valve.
2. Increase gas pressure.
3. Clear obstruction in vent orifice/
line or replace if defective.
4. Check for correct installation and
voltage. Correct or replace.
5. Replace with factory required
type of gas.
6a. UV Sensor - clean lens and sight
tube and check wiring and spark
plug.
6b. Flame Rod - assure rod is in
flame, check wiring and flame
rod.
7. Check wiring or replace
transformer if correct.
1. Place in run position (see
technical cut sheet on flame
safeguard relay).
1. Disable the fan and heat. Slowly
open all manual gas shut-off
valves before restarting.
2. Clear obstruction in vent orifice/
line or replace if defective.
3. Enable the fan and heat. After
10 seconds of prepurge, pilot will
light. Then after 10 seconds main
valve light will come on. Check to
see if all gas valves have opened.
If not, check voltage at gas valve.
If voltage is found to be correct,
replace gas valve or actuator
(see Section X on Maxitrol
troubleshooting Guide for
modulating valve).
4a. Check burner for low fire
adjustment.
4b. UV Sensor - clean lens and sight
tube and check wiring.
4c. Flame Rod - be sure flame rod is
in main flame, check wiring and
flame rod.
5. Check for power and/or replace.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
– 23 –
SECTION VII - TROUBLESHOOTING continued
Heat Mode continued
Symptom
Cause
Remedy
G. No heat with pilot ok and no
voltage is present at flame
safeguard relay output
terminals.
1. Flame safeguard relay Run/
Test switch in Test position or
fucntioning problem.
1. Place in Run position (see
technical cut sheet on flame
safeguard relay).
H. Burner will not respond
to temperature.
1. For DDC System.
1. See Digital Control System User
manual.
2. Refer to following troubleshooting
guide for RTC controls.
2. For RTC RE-26.
I.
J.
Mixing Box with Airflow
Station dampers not
functioning properly. See
Sequence of Operation
for damper control.
Return air/outside air
or discharge air/profile
damper operation not
functioning properly (see
sequence of operation
for damper control).
K. Burner will not come on
in low speed.
1. Defective or misadjusted
transducer (PT-15).
2. Transducer (PT-15) wired
incorrectly.
3. Transducer (PT-15) not installed
correctly.
4. Unit Control Module (UC-01)
defective.
5. Unit Control Module (UC-01) not
wired correctly.
6. Damper motor defective.
7. Dampers binding and/or loose.
1. Check and/or replace. See
section on troubleshooting PT-15.
2. Check wiring.
1. Building Pressure Transducer
(PT-13), Damper Control
Potentiometer, or null switch
defective or not calibrated.
2. Building Pressure Transducer
(PT-13), Damper Control
Potentiometer, or null switch not
wired correctly.
3. Building Pressure Transducer
(PT-13), Damper Control
Potentiometer, or null switch not
installed correctly.
4. Unit Control Module (UC-01)
defective.
5. Unit Control Module (UC-01) not
wired correctly.
6. Two position switch defective.
7. Damper motor defective.
8. Dampers binding and/or loose.
1. Check and/or replace
components. See section on
trouble shooting PT-13.
1. Low air flow switch open.
1. Check to make sure velocity is
correct.
2. Check and/or replace.
2. Profile damper and/or motor not
closing.
L. Flame length too long
in low speed.
1. High fire set incorrectly.
2. Profile damper not operating
correctly and/or damper motor
defective.
3. Install correctly. See section on
troubleshooting PT-15.
4. Check and/or replace. Contact
Factory.
5. Check wiring.
6. Check and/or replace.
7. Check and repair.
2. Check wiring.
3. Install correctly. See section
on trouble shooting PT-13 and
manufacturer’s cut sheet.
4. Check and/or replace. Contact
Factory.
5. Check wiring.
6. Check and/or replace.
7. Check and/or replace.
8. Check and repair.
1. See Section X for Manifold and
Valve Adjustments.
2. Check and/or replace.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
– 24 –
TROUBLESHOOTING GUIDE FOR AMPLIFIER (RE-26)
The SC-1 signal conditioner
provides signal conversion for a
high impedance 2-10VDC signal
source to drive a 24VDC solenoid.
The control should be powered by
an isolated 24VAC transformer to
drive up to a .5A dc solenoid.
Span Override Switch - When terminals 3 & 4 are
shorted together the span setting is ignored forcing the
ratio to 100%.
Start Up Delay - The unit will pause for 10 seconds
after power is applied to begin driving the output.
Power/Status LED
A solid green LED indicates power and normal
operation.
A slow blinking green LED indicates power but the 10
second start up delay has not completed.
A fast blinking green LED indicates the the input signal
is out of range or may be reversed.
– 25 –
TROUBLESHOOTING GUIDE
Modulating Discharge Temperature (MDT or MDT EXPERT) Controls
Portions reproduced with permission from Maxitrol® Company
Symptom
Possible Cause
A. No Gas Flow
with DO-2
on UC-01
energized.
1. Modulating valve
improperly installed.
1. Arrow on side of valve should
point in direction of gas flow.
1. Install properly.
B. Continuous Low
Fire (Electronics
Problem).
1. Short circuit or no
voltage to the amplifier
(RE-26).
2. Faulty amplifier (RE-26).
1. Check for 24V AC at
amplifier (RE-26) terminals
7 & 8.
2. Check item B1. Check
for 0-10 VDC input signal
from (UC-01) at terminals
1 & 2. Check for 0-20 VAC
output signal to gas valve at
terminals 5 & 6.
3. Check DC Voltage on AO-1.
1. Prove the power source.
3. No output voltage on
UC-10.
4. Jumper not connected
across amplifier (RE-26)
terminals 3 & 4.
C. Continuous Low
Fire (Electronics
OK).
Field Test
4. Inspect.
Remedy
2. If item B1 checks out and
modulating voltages are
still not obtained, amplifier
(RE-26) may be assumed
faulty. Replace.
3. Contact Factory.
4. Correct the wiring.
1. Short circuit or open
circuit in Modulator Coil.
1. Measure resistance across
modulator terminals 5 & 6 with
connecting wires detached.
1. Replace modulator head
if not approximately 45-55
ohms for M611 Valve and
60-80 ohms for MR212
Valve.
2. Clean or replace plunger if
necessary.
2. Plunger missing,
jammed or improperly
installed.
2. Inspect. Plunger should be
installed to operate freely in
solenoid sleeve.
D. Incorrect
Minimum Fire
Erratic or
Pulsating Flame.
1. Incorrect by-pass
metering valve
adjustment.
2. Excessive negative
burner pressure.
1. See valve adjustments in
Section X.
1. Adjust to proper minimum
fire.
2. Close main gas supply and
measure manifold pressure
with blower operating.
Reading should be less than
1.5" w.c. negative pressure.
2. If reading is greater than 1.5"
negative pressure, check
for clogged filters or other
inlet air restrictions. Consult
factory for other solutions.
E. Continuous High
Fire (Electronics
Problem).
1. Open circuit in Outside
Air Temperature Sensor
(TS-01) or Discharge
Air Temperature Sensor
(TS-03) circuit or wiring.
1. Check Outside Air
Temperature Sensor
(TS-01) or Discharge Air
Temperature Sensor (TS-03)
for open internal circuit. See
Thermistor curve.
1. Replace Outside Air
Temperature Sensor (TS-01)
or Discharge Air Temperature
Sensor (TS-03
F. Continuous High
Fire (Electronics
OK).
1. Foreign object holding
valve open.
2. Plunger jammed.
1. Remove bottom plate and
inspect valve and seat.
2. Inspect. Plunger should
be smooth and clean and
operate freely in solenoid
sleeve.
1. Clean seat. Clean valve or
replace if necessary.
2. Clean, or if necessary,
replace plunger.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
– 26 –
TROUBLESHOOTING GUIDE
Modulating Discharge Temperature (MDT or MDT EXPERT) Controls continued
Symptom
G. Incorrect
Maximum Fire.
Possible Cause
1. Inlet pressure too low.
2. Incorrect outlet pressure
adjustment of Pressure
Regulator.
H. Incorrect
Discharge Air
Temperature
1. Unit Enable Potentiometer
(MP-15) not set correctly.
2. Discharge Air
Temperature Sensor
(TS-03) not reading
correctly.
3. The Heating Discharge
Air Setpoint on
MDT-EXPERT Control
System is not set
correctly.
I. Burned out
Transformer.
1. Short circuit in
modulator coil.
2. Short circuit between
amplifier and modulator
valve.
Portions reproduced with permission from Maxitrol® Company
Field Test
Remedy
1. Read pressure at inlet to
modulating valve using
a manometer with unit
operating at full fire.
Pressure should be equal
to the sum of outlet pressure
setting plus pressure drop
of the valve.
2. Read manifold pressure
using manometer and
compare with the pressure
stated on the specification
plate.
1. Increase inlet pressure if
possible.
1. Check setpoint on Unit
Enable Potentiometer
(MP-15)
2. Check Discharge Air
Temperature Sensor (TS-03)
and wiring. See Thermistor
curve.
3. Check setpoint with BACview
or PC.
1. Change to correct setpoint
setting.
1. Measure resistance across
modulator terminals with red
lead wires disconnected.
2. Inspect wiring.
1. Replace modulator head if
less than 40 ohms.
2. See valve adjustments in
Section X.
2. If readings are not correct,
replace Discharge Air
Temperature Sensor (TS-03)
or repair wiring.
3. Change to correct setpoint.
See Digital Control System
User Manual.
2. Correct wiring if short is
found.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
– 27 –
TROUBLESHOOTING GUIDE
Modulating Room Temperature (MRT, MRT-PRO or MRT-EXPERT) Controls
Symptom
Possible Cause
Portions reproduced with permission from Maxitrol® Company
Field Test
Remedy
A. No Gas Flow with
DO-2 on UC-01
energized.
1. Valve improperly
installed.
1. Arrow on side of valve
should point in direction
of gas flow.
1. Install properly.
B. Continuous Low
Fire (Electronics
OK).
1. Open circuit in
modulator coil.
1. If proper resistance values
are not observed, replace
modulator head or repair
wiring.
2. Plunger missing,
jammed or improperly
installed.
3. Ruptured main or
balancing diaphragm.
1. Remove wires connected
to amplifier terminals 5 & 6
and measure resistance.
MR212 (60-80 ohms),
M611 (45-55 ohms).
2. Inspect - plunger should be
installed to operate freely in
solenoid sleeve.
3. Disassemble valve for
inspection of internal parts.
1. No voltage to the
amplifier.
2. Short in modulator
coil circuit.
1. Check for 24V AC at
amplifier terminals 7 & 8.
2. Measure resistance per
item B1.
1. Provide 24V AC to amplifier.
3. Faulty amplifier (RE-26).
3. Check for 0 – 10 VDC input
signal from Unit Control
Module (UC-01) at terminals
1 & 2. Check for 0 – 20 VDC
output signal to gas valve at
terminals 5 & 6.
4. Check voltage on AO-1.
C. Continuous Low
Fire (Electronics
Problem).
4. No output voltage on
UC-01.
D. Incorrect
Low Fire.
1. Incorrect by-pass metering
valve adjustment.
2. Excessive negative
burner pressure.
E. Continuous
Minimum
Discharge Air
Temperature.
1. Incorrect room
temperature.
F. Incorrect
Maximum
or Minimum
Discharge Air
Temperature.
1. Maximum or minimum
heating discharge
temperature setpoint
not set correctly.
1. See Valve Adjustments
Section X.
2. Close main gas supply and
measure manifold pressure
with blower operating.
Should be less than 1.5" w.c.
negative pressure.
2. Clean or replace plunger if
necessary.
3. Replace diaphragm if
ruptured.
2. If proper resistance values
are not observed, replace
the modulator head or repair
wiring.
3. If power source and
modulator coil check out
(items 5 & 6) but proper
modulating voltages cannot
be obtained, then amplifier
may be assumed at fault.
Install replacement amplifier.
4. Consult factory.
1. Adjust to proper low fire.
2. If greater than 1.5" negative
pressure, check equipment
for clogged filters and other
inlet air restrictions. For other
solutions, consult factory.
1a. Check Outside Air Sensor
1a. Replace Sensors if reading is
(TS-01),Space Temperature
incorrect or correct wiring.
Sensor (TS-02) and Discharge
Air Sensor (TS-03) for correct
readings. See Thermistor curve.
1b. Check Space Temperature
1b. Change to correct setpoint.
Sensor (TS-02) and/or Unit
Enabled Poteniometer (MP15) setpoint.
1c. Change to correct setpoint.
1c. Check Heating Occupied
and/or Unoccupied setpoint.
1. Install a BACview 6 or PC.
1. Change to correct setpoints.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
Control circuits external to MRT Controls can cause burner malfunction.
Always check manual valve to be certain gas is on, and check limit controls for normal operation.
– 28 –
TROUBLESHOOTING GUIDE
Modulating Room Temperature (MRT, MRT-PRO or MRT-EXPERT) Controls continued
Symptom
Possible Cause
Portions reproduced with permission from Maxitrol® Company
Field Test
Remedy
G. Continuous High
Fire (Electronics
Problem).
1. Foreign material
holding valve open.
2. Plunger jammed.
1. Remove bottom plate and
inspect valve and seat.
2. Inspect - plunger should be
smooth and clean and operate
freely in solenoid sleeve.
1. Clean, replace valve and/or
seat if necessary.
2. Clean, or if necessary,
replace plunger.
H. Continuous High
Fire (Electronics
OK).
1. Open circuit in Outside
Air Temperature Sensor
(TS-01) or Discharge
Air Temperature Sensor
(TS-03)
1. Measure resistance per
Thermistor Curve.
1. If readings are incorrect,
replace Outside Air
Temperature Sensor (TS-01)
or Discharge Air Temperature
Sensor (TS-03) or repair
wiring.
I. Incorrect High
Fire.
1. Inlet pressure too low.
1. Read inlet pressure at
valve, using a manometer
with heater operating at full
fire. Pressure should be at
least equal to the sum of:
outlet pressure setting and
pressure drop of the valve
plus 1.0" w.c.
2. Read outlet pressure using
manometer and compare
with the pressure stated on
the specification plate.
1. Increase inlet pressure
if possible or change to
larger valve. Consult factory
about possibility of using
special spring to reduce
pressure drop on selected
installations.
2. Incorrect outlet
pressure adjustment.
2. See Valve Adjustments
-Section X.
1. Open circuit in
Discharge Air
Temperature Sensor
(TS-03).
2. Incorrect Maximum
Heating Discharge
Temperature Setpoint.
1. Measure resistance per
Thermistor Curve.
K. Burned out
Transformer.
No Voltage to
Amplifier.
1. Short in modulator
coil circuit.
1. Measure resistance per
item B1.
1. If proper resistances are not
observed, replace modulator
head or repair wiring.
L. Incorrect Space
Temperature.
1. Incorrect Minimum
Heating Discharge
Temperature Setpoint.
1. Check to see if heater
is delivering at Minimum
Discharge Setpoint.
1. If desired Space Temperature
is not reached, increase
Minimum Heating Discharge
Setpoint.
2a. Change to correct setpoint.
J. Continuous
Maximum
Discharge Air
Temperature.
2. Check to see if heater is
delivering at Maximum
Heating Temperature
Discharge Setpoint.
2. Incorrect space setpoint. 2a. Check Unit Enable
Potentiometer (MP-15)
Setpoint.
2b. Check Heating Occupied
and/or Unoccupied setpoint.
3. Insufficient burner
3. Check to see if heater is
capacity.
operating at high fire.
1. If readings are incorrect,
replace Discharge Air
Temperature Sensor
(TS-03) or repair wiring.
2. If desired temperature is
not reached, increase
Maximum Heating Discharge
Temperature Setpoint.
2b. Change to correct setpoint.
3. If desired Space Temperature is not reached with
heater at high fire, it may be
undersized. Consult Factory.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
Control circuits external to MRT Controls can cause burner malfunction.
Always check manual valve to be certain gas is on, and check limit controls for normal operation.
– 29 –
TROUBLESHOOTING GUIDE
Cooling Mode
Symptom
Cause
Remedy
A. There is no voltage at cooling relays
(RE-34) (RE-35) and/or (RE-33) and
the fan is enabled.
1. Cooling mode is disabled
2. Auxiliary switch on starter (ST-01)
is not closed.
3. Air flow switches open.
1. Enable the cooling mode.
2. Check auxiliary circuit wiring and
contact.
3. Adjust the air flow and external
static pressure to match the unit
rating plate. DO NOT ADJUST
SWITCHES.
4. Change to correct setpoints. See
Digital Control User Manual.
4. Cooling Changeover and/or
Economizer Setpoints not set
correctly.
5. DO-3 and/or DO-4 are not
energized.
B. Cooling relays (RE-34) (RE-35)
and/or (RE-33) are energized and
condensing unit or evaporative
cooler is not on.
C. Incorrect Space Temperature.
5. See Digital Control System User
Manual.
1. Cooling relays (RE-34) (RE-35)
and/or (RE-33) contacts are not
closed.
2. Cooling relays (RE-34) (RE-35)
and/or (RE-33) contacts are not
wired correctly.
3. Compressors or evaporative pump
not running.
1. Check and/or replace.
1. Incorrect Maximum Cooling
Discharge Temperature Setpoint.
1. Decrease Maximum Cooling
Discharge Temperature Setpoint.
See Digital Control System User
Manual.
2. Decrease Minimum Cooling
Discharge Temperature Setpoint.
See Digital Control System User
Manual.
3. Change to correct setpoints.
See Digital Control System User
Manual.
4. Change to correct setpoint settings.
See Digital Control System User
Manual.
5. If desired Space Temperature is
not reached and cooling is at full
capacity, it may be undersized.
6. See Troubleshooting Guide for your
condensing unit or evaporative
cooler.
2. Incorrect Minimum Cooling
Discharge Temperature Setpoint.
3. Unit Enable Potentiometer (MP-15)
not set correctly.
4. Cooling Occupied and/or
Unoccupied setpoints not set
correctly.
5. Insufficient cooling.
6. Condensing section or evaporative
cooler is not operating correctly.
2. Correct wiring.
3. See Troubleshooting Guide for your
condensing unit or evaporative
cooler.
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
– 30 –
TROUBLESHOOTING GUIDE
To Calibrate the Building Pressure Transducer
(PT-13)
1. Remove the tubes at the Low and High pressure
fittings.
2. The voltage at –COM and OUT should be 2.5 VDC.
If not adjust Z (do not adjust S).
3. Make sure the Low and High fittings are clean
and clear (do not insert any sharp objects into
the pressure fittings). Make sure the tubing is
also clean, clear of any debris and then reinstall
the tubes on the transducer. It is very important
that the High tube be placed inside the building,
and positioned so that air movement does not
affect it. The Low side should be to atmosphere,
and positioned so it is not exposed to the
weather.
4. With the use of a BACview 6 (KP-01) place the
unit in the Building Pressure mode. (See the Digital
Control System User Manual).
5. The voltage at –COM and OUT will vary between
0 to 5 VDC. O VDC means the building is in a
negative pressure and should open the Outside
Air/Profile and close the Return Air damper. 5 VDC
means the building is in a positive pressure and
should open the Return Air Damper and close the
Outside Air/Profile Damper.
To calibrate the Flow Station Pressure Transducer
(PT-15)
1. Remove the tubes at the Low and High pressure
fittings.
2. The voltage at –COM and OUT should be O VDC.
If not adjust Z (do not adjust S).
3. Make sure the Low and High fittings are clean
(do not insert any sharp objects into the
pressure fittings) make sure the static pressure
sensing pitot tubes and all tubing is also clean,
clear of any debris and then reinstall the tubes
on the transducer. It is very important that
the Low and High tubes from the Flow Station
are installed on the transducer correctly (see
drawing #C000643 on page 8).
4. With the use of a BACview 6 (KP-0l) place the unit
in the Calibration Mode (see the Digital Control
System User Manual). You can also short across
the TS-01 and TS-03 terminals on UC-01 for ten
(10) seconds.This will open the Return Air damper
and close the Outside Air damper. The unit will
calibrate for 5 minutes. IMPORTANT: Be sure
there is no blockage in the return air duct.
5. The voltage at –COM and OUT should be at least
2 VDC. If the voltage is less than 2 VDC contact the
factory.
PT-13
PT-15
SETRA P/N
MESTEX P/N
RANGE
SETRA P/N
MESTEX P/N
RANGE
26510R1WBABT1C
68.0330.69
± .1 IN WC
26510R1WDABT1C
68.0330.66
0 - 0.1 IN WC
2651R25WDABT1C
68.0330.67
0 - .25 IN WC
26510R5WDABT1C
68.0330.68
0 - .5
– 31 –
IN WC
TROUBLESHOOTING GUIDE
Checking The Burner Velocity Pressure
PS-10 & PS-11 air switches are factory calibrated.
Do not adjust.
The permissible pressure range should be marked on
the switches. If it’s close to the high or low trip points of
the airflow switches, you could have nuisance burner
shutdowns. High Velocity Switch open means too
much velocity and Low Velocity Switch open means
not enough velocity across the burner profile plates.
Some adjustments can be made by repositioning the
burner profile plates. If the velocity will allow the High
Velocity Switch to open, you can open the profile
plates. If the velocity will allow the Low Velocity Switch
to open, you can close the profile plates. REMEMBER
to keep the opening between the burner and profile
plates the same on both top and bottom of the burner
when making these adjustments.
Depending on the motor amps, you may want to
change the speed of the fan if the unit has adjustable
sheaves.
Check the velocity pressure by disconnecting both
pressure sensing tubes from the High Velocity Switch.
Connect your manometer to each sensing tube so you
can measure the differential pressure and then enable
the fan.
Enable the burner and get it running in high fire – See
Section X in this manual. Your differential pressure
should now be lower. If it is near the Low Velocity
Switch trip point, you need to increase the velocity.
The ideal velocity is in the middle of the High Velocity
Switch and Low Velocity Switch trip points.
CAUTION: Be sure to turn the power and gas off
to the unit before you access the burner. Follow
proper "lockout/tagout" procedures.
Don’t forget to remove any jumpers and reconnect
the sensing tubes to the switch.
Call the factory if you have any questions.
– 32 –
MULTIPLEXED VOLTAGE CHART
RESISTOR
VALUE
RESISTOR ID
1000
2000
4020
8060
RS1
RS2
RS3
RS4
MULTIPLEXED VOLTAGE
VALUES
SWITCH
CLOSED
OHMS IN
CIRCUIT
VOLTS DC
RS1,2,3,4
RS2,3,4
RS1,3,4
RS3,4
RS1,2,4
RS2,4
RS1,4
RS4
RS1,2,3
RS2,3
RS1,3
RS3
RS1,2
RS2
RS1
NONE
UNPLUGGED
0
1000
2000
3000
4020
5020
6020
7020
8060
9060
10060
11060
12080
13080
14080
15080
NA
0
0.30
0.55
0.76
0.95
1.10
1.24
1.36
1.47
1.57
1.65
1.73
1.80
1.87
1.92
1.98
3.30
IN-3
TO
GND
JUMPER
RE-56
RE-09
SW-72
RS-04
RS-03
RS-02
RS-01
MIXED AIR TEMP
SAFETY CKT STATUS
FLAME FAILURE
100% OA or 100% OUTPUT
= 1.36
= 1.73
= 1.87
= 1.92
IN-4
TO
GND
RE-27
RE-65
RE-12
SW-09
RS-04
RS-03
RS-02
RS-01
BURNER STATUS
FAN STATUS
CLOGGED FILTER
AUXILIARY UNIT ENABLE
= 1.36
= 1.73
= 1.87
= 1.92
CHECK ALL TERMINAL CONNECTIONS FOR TIGHTNESS
The DC voltage is to be checked at the UC-01 board
With the Fan and Burner Enabled:
With the Fan Enabled:
When the fan status relay (RE-65) is energized, the
contacts will close and the VDC at IN-4 & GND will be
1.73.
When the safety circuit relay (RE-56) is energized,
the contacts will close and the VDC at IN-3 & GND
will be 1.73. When the burner status relay (RE-27) is
energized, the contacts will close and the VDC at IN-4
& GND will be 0.76.
– 33 –
SECTION VIII - MAINTENANCE SCHEDULE AND LUBRICATION REQUIREMENTS
WARNING: Failure to comply with the general
safety information may result in extensive
property damage, severe personal injury or
death.
Periodic maintenance is essential to the efficient
operation and extended service life of this equipment.
Failure to provide maintenance as recommended may
void the equipment warranty.
A. Maintenance Schedule
1. Daily
a. Check gauges, monitors, instruments and equipment
settings.
2. After 8 hours of operation
a. Check that fan belts are tight and sheaves are aligned.
The fan belts can be checked every 30 days after the
first 60 days of new belt run-in. CAUTION: Do not
overtighten belts.
b. Check set screws and bolts on the fan, bearings,
couplings, and burner assembly.
c. Check gas pressure at regulator.
3. After 48 hours of operation, check bearings for any
unusual vibration or excessive temperature.
4. Monthly
a. Check all valves, piping and connections for leaks.
b. Check the flame signal.
c. Check the fuel pressure in the fuel supply line to each
heater.
d. Check the burner manifold pressure at full fire.
Care must be taken not to damage optional
lube lines. At low fire setting, be sure there is a
continuous flame along the entire burner length
without any blowout spots.
e. Clean the flame sensor(s) or UV sight tube(s).
f. Inspect filters. Clean or replace as necessary.
g. Inspect the main fan bearings, lubricate is necessary.
See Section VIII on bearing maintenance.
h. Check all dampers, damper actuators and linkages.
Adjust and tighten if necessary.
i. Ensure that there are no obstruction blocking the air
supply to the heater or the air discharge from the
heater.
j. Inspect the area and make sure that no combustible
or hazardous material has been stored within the
clearances as shown on the unit nameplate.
k. Check and clear all air sensing tubes and
fittings. CAUTION: Remove tubes from switches,
transducers, and flow station before using
compressed air to blow through tubing.
l. Test ignition spark. There should be a continuous
spark for 10 seconds with pilot gas turned off.
5. Quarterly
a. Complete the monthly maintenance schedule.
b. Inspect all drives for proper belt tension and wear.
c. Check the alignment of the sheaves and adjust if
necessary.
d. Inspect all bearings set screws for tightness and lubricate bearings if necessary.
e. Check the pilot electrical system. Adjust if necessary.
f. Check the pilot assembly. Clean and adjust if necessary.
g. Inspect the burner carefully. Clean and adjust if necessary.
h. Check voltages and amp draw on main fan motor.
i. Check the operation of all safety controls individually.
j. Check the operation of the automatic gas shut off
valves and check them for leakage at the pressure
test ports provided.
k. On vertical units inspect burner clean out and drain if
necessary.
l. Check that the battery in (UC-01) has 3 VDC. Do
not remove or replace battery with the power
turned off to the control.
6. Off Season or Yearly
a. Complete the monthly and quarterly maintenance
schedule.
b. Inspect all fan wheels and housings. Clean if necessary.
c. Check that all fan wheels, sheaves, and couplings are
securely set on the shaft.
d. Inspect all bearings and alignment. Adjust if necessary.
e. Inspect all V-belts, sheaves, and coupling inserts.
Replace if necessary.
f. Inspect all electrical components, connections and
terminals. Clean and tighten where necessary.
g. Test ignition spark. Adjust gap if necessary.
h. Clean ignition electrodes and check for cracks.
i. Test flame safeguard relay and replace components if
necessary.
j. Inspect all regulators, relief valves, motorized valves,
solenoid valves, vent valves, manual shut off valves
and safety shut off valves. Check their operation and
clean as necessary.
k. Ensure all vents to the atmosphere are clean and free
from obstruction.
l. Inspect and clean all drip legs in the fuel line.
m. Lubricate fan motor as directed by motor manufacturer.
n. Inspect fan motor wiring for loose connections.
o. Lightly oil all door latches.
p. Check that cabinet is weathertight, replace door gaskets and recaulk as necessary.
NOTE: Keep screened air intakes clear of obstructions at all times.
– 34 –
B. Lubrication Instructions
2. Pillow Block Bearings – Pillow block bearings are used
on supply blower(s). Bearings have been pre-lubricated
with high-quality lithium-complex base grease with
an EP additive. The grease is a lithium-complex base
mineral oil, NLGI Grade 2 consistency, with a base oil
viscosity of ISO VG220. Re-lubrication should be done
with lithium-complex thickened grease with a comparable NLGI consistency and base oil type and viscosity.
Wipe all grease fittings clean before adding grease.
Grease should be added slowly, in small amounts at
frequent intervals while the shaft is being manually
rotated.
Item
Manufacturer
Bearing Type
All 3 phase
US., Baldor
Single row ball
fan motors
or equal
bearings
(1 HP to
100 HP)
ODP, TEFC
Recommendation: See following note.
All 1 phase
Century, G.E.,
Bronze sleeve
motors
or equal
bearings
(Fractional
HP) ODP,
TEFC or
TEAO
Recommendation: See following note.
A slight showing of grease at the seals with accompanying normal bearing temperature indicates proper
lubrication. Normal temperature can range from “cool”
to “hot to the touch” depending on size, speed and
surrounding conditions. Excessive bearing temperature
indicates faulty lubrication. An insufficient amount of
grease is suggested by a bearing showing no grease
at the seals, and a higher than normal temperature
and noise level. Excessive leakage of grease at the
seals, and a high operating temperature suggest too
much grease.
Fractional HP Century, G.E.
Bronze sleeve
single phase, or equal
bearings
ODP or
TEFC
Recommendation: See following note.
Fan shaft
bearings
Fafnir
or equal
Self-aligning
single row or
double row
ball bearings,
resilient mounted
Recommendation: See following note.
Dampers
Factory
Sleeve
or equal
Recommendation: See following note.
1. Blower Motors – Some motors require lubrication
while others do not. Those that require lubrication can
be identified by the presence of grease plugs in the
motor casing at each end. Motors that do not have
grease plugs cannot be greased and are lubricated for
the life of the motor bearing.
Lubrication of motors should be done while the motor is warm and at a standstill. Remove and clean all
grease plugs and insert a grease fitting in the upper
hole in the motor casing at each end. (Viewed as if
motor were sitting horizontally on its base). There may
be one or two plugs in each end casing of the motor.
Add a small amount of a clean, good grade ball bearing grease, such as Exxon Polyrex EM or equal, with a
low pressure grease gun. Run the motor five minutes
before removing the grease fittings and replacing the
plugs.
Frequency of Lubrication – Frequency of lubrication depends upon operating conditions. The bearing
operating temperature is the best index for determining a relubrication schedule. The following chart gives
the frequency of relubrication based upon continuous
operation for various operating temperatures and can
be used as a satisfactory guide for determining when
all ball and roller bearings should be relubricated.
Speed
100 RPM
500 RPM
1000 RPM
1500 RPM
Any Speed
Any Speed
Any Speed
Any Speed
100 RPM
500 RPM
CAUTION: An excess of grease will overheat the
bearings.
NOTE: On totally enclosed fan cooled (TEFC)
motors, the rear end fan housing must be removed
to expose the grease plugs.
– 35 –
Temperature Cleanliness Interval
Up to 125°F Clean
4 to 10
months
Up to 150°F Clean
1 to 4
months
Up to 210°F Clean
2 weeks
Over 150°F
Clean
weekly
Up to 150°F Dirty
1 week
to 1 month
Over 150°F
Dirty
daily to
1 week
Any Temp.
Very Dirty
daily to
1 week
Any Temp.
Extreme
daily to
Conditions
1 week
Roller Bearings
Up to 125°F
Up to 150°F
Clean
Clean
1–4
months
1 week to
1 month
Browning Bearing Set Screw Torque Values
Model#
Shaft Size
Torque (in-lbs)
Set Screw
VPS-212
VPS-214
VPS-116
VF2S-116
VPS-219
VF4S-219
VPS-220
VPS-223
VPS-323
VF4S-227
VPS-327
VPS-231
VF4S-231
VPS-331
VPS-235
VF4S-235
VPS-236
VPS-239
VF4S-243
VPS-343
VPS-347
3/4
7/8
1
1
1 3/16
1 3/16
1 1/4
1 7/16
1 7/16
1 11/16
1 11/16
1 15/16
1 15/16
1 15/16
2 3/16
2 3/16
2 1/4
2 7/16
2 11/16
2 11/16
2 15/16
66 - 85
66 - 85
66 - 85
66 - 85
66 - 85
66 - 85
126 - 164
126 - 164
126 - 164
126 - 164
228 - 296
228 - 296
228 - 296
228 - 296
228 - 296
228 - 296
228 - 296
228 - 296
348 - 452
348 - 452
348 - 452
BOA Concentric
VPB-231
VPB-331
1 15/16
1 15/16
220 - 240
220 - 240
Spherical Roller
USFB5000
USFB5000
USFB5000
USFB5000
USFB5000
USFB5000
USFB5000
USFB5000
1 3/16
1 7/16
1 11/16
1 15/16
2 3/16
2 7/16
2 11/16
2 15/16
165
165
165
295
295
295
655
655
Sealmaster Sleevloc
USRB5000A 115C 1 15/16
8. Slide the new shaft through the first blower wheel
hub.
9. Once the shaft is completely through the first
blower wheel, slide a bearing onto this end of the
shaft by pushing on the inner ring. Do not use a
hammer.
10. Slide the shaft through the next blower wheel hub
and add another bearing. Continue this procedure
until the shaft is through all of the blower wheels.
11. Place a bearing on each end of the shaft.
12. Replace the shims as required.
13. Install bearing mounting bolts (do not tighten) and
check alignment.
14. Tighten the bearing bolts to recommended torque
shown below and reattach grease lines. (When
installing USRB5000A 115C bearing, see note of
following page).
15.
ASTM A307 Recommended
Tightening Torque
30
When replacing bearings refer to the manufacturer’s
installation instructions included with the bearing.
Typical Procedure For Changing The Shaft And
Bearings
1. Remove protective shaft coating.
2. Remove the drive side sheave.
3. Disconnect the grease lines from the existing
bearings.
4. Remove mounting bolts for bearings and remove
any shims.
5. Identify the total shim thickness at each bearing
and mark the bearing mount for future reference.
6. Loosen bearing and blower wheel shaft setscrews.
7. Remove the shaft from the unit by sliding the
bearings and blower wheel(s) along the shaft as
the shaft is extracted. Unless a blower wheel is
damaged, it should be unnecessary to remove the
blower wheel from the blower housing.
Bolt Size
TPI
ft lbs
1/4
20
4
5/16
18
7
3/8
16
13
7/16
14
21
1/2
13
32
9/16
12
46
5/8
11
64
16. Adjust the shaft so the blower hub keyways are in
the middle of the shaft keyways.
17. Adjust the shaft so it protrudes past the non-drive
end bearing, the blower sheave keyway mates with
the shaft keyway and the drive side sheave can be
aligned with the motor sheave. Ideally, the blower
sheave should be as close to the drive side bearing
as possible, the motor sheave should be as close
to the motor housing as possible, and the belts
should be straight.
18. Be sure the shaft does not rub on or interfere with
the closing of the access door.
19. Align all bearing setscrews, so that the same
setscrew on each bearing is pointed in the same
direction as the other bearings’ setscrews.
20. Check shaft for freedom of rotation by rotating shaft
by hand in both directions.
21. Place a drop of “BLUE” Loctite on the bearing
setscrews and tighten all of the setscrews. Follow
the mounting instructions procedure on the inside
of the bearing box or accompanying instructions for
proper tightening and torque values.
22. Align the blower hubs’ keyway with those in the
shaft. Be sure the clearance between the blower
wheel and blower housing is the same on each
side.
23. Rotate the shaft by hand to insure free operation.
Correct any rubbing of the blowers on the housings.
– 36 –
24. Place a drop of “BLUE” Loctite on the blower
setscrews and tighten all of the setscrews.
25. Align the blower and motor sheaves using a laser
or straight edge and tighten the blower sheave to
the shaft.
26. Replace the belts and tighten the motor base
adjustment for the proper belt tension. Over
tightening the belt tension will severely reduce
belt and bearing life. Belt deflection should be
approximately 1/64 inch for every inch of span
length.
27. Monitor for excessive heat or vibration during
operation.
28. All bearings are pre-lubricated and should not
initially require greasing. See previous section for
bearing maintenance instructions.
the same type and size. In addition, the factory not
only suggests, but insists, that air filters be checked
every 30 days (daily in icy or snowy weather) and
replaced with new filters (throw-away type) or cleaned
(washable type) as required. Cleanable filters should
be given new application of filter coating after washing
to maintain optimum filter performance.
The frequency of cleaning and replacing air filters
applies twelve months of the year, where blowers
are used for ventilation and heating.
D. Belt Tensions and Adjustments
Belt tension is adjusted during the initial run-in and test
periods at the factory. However, the belts are run as
slack as possible to prevent excessive damage to the
bearings, yet tight enough to prevent slippage.
Note: Drive side Sleevlock bearing installation
(USRB5000A 115C)
WARNING: Do not apply grease, oil, or anti-seize
compound to the tapered surface, bore, or
shafting. If any of these substances are applied,
equipment failure and personal injury may
result.
1. Mount all the bearings and leave all of the bolts
and setscrews loose.
2. Tighten setscrews on the bearing to the
tightening pattern as described in the
installation sheet that comes with the bearing
to a final 30 inch lbs torque while rotating the
shaft. Check to make sure the insert of the
bearing is centered in the bearing housing and
then bolt bearing down.
3. Tighten down the bolts and setscrews on
the remaining bearings per installation sheet
starting from the non-drive end bearing back
towards the Sleevlock while rotating the shaft.
3. Dampers – Dampers should be inspected monthly
(daily in icy or snowy weather) for securely fastened
linkages, and smooth operation. If dampers are binding
or excessively noisy, then lubrication may be required.
Place one drop of #20 wt. machine oil on each blade
bearing, and linkage ball joint. Do not over lubricate,
and wipe any excess from the area. Be sure to note
that dampers over 49 inches long have intermediate
bearings which require lubrication. On outdoor models
with factory supplied discharge dampers, you will need
to remove to top cover to access the damper bushings.
Replace cover and caulk as necessary.
C. Air Filters
All filter banks should be equipped with a manometer
or differential pressure switch to indicate when the
filters are dirty. Filters should be replaced when
the differential pressure across them reaches the
manufacturer’s recommended final value. Dirty filter
elements should be replaced with a clean element of
It is necessary, therefore, to tighten all belts during the
first few months of operation, and to check for proper
tension weekly during the first 60 days, after which
30-day check intervals are sufficient.
NOTE: Turn off all power to the equipment before
checking belt tensions.
CAUTION: Do not attempt to tighten any belt or belts
by changing the pitch of an adjustable pulley, as this
will change the speed of a driven pulley, causing the
unit to be rendered OUT OF AIR BALANCE. Do not
overtighten belts.
Suggested Belt Tension Method is with the use of a
Belt Tension Checker
1. Check tension frequently during the first 24-48
hours of run-in operation. Ideal tension is the
lowest tension at which the belt will not slip under
peak load conditions. Over tensioning shortens belt
and bearing life.
Alternate Belt Tension Method
2. To properly tension a conventional V-belt drive use
the following procedure:
a. Measure the span length.
b. At the center of the span, apply a force perpendicular to the span to deflect the belt 1/64 inch
for every inch of span length. For example, for a
40 inch span, apply a force that will deflect the
belt 40/64 or 5/8 of an inch.
c. Compare the force you have applied with the
values given in the table below. If the force is
between the values for normal tension and 1-1/2
times normal tension, the belt tension should be
satisfactory. If the belt tension is not within this
range, it can be adjusted by loosening the motor
mounting bolts, and adjusting the position of the
motor along its base.
– 37 –
B Section
small
Pounds
pulley
Pounds
Force for
diameter Belt
Force for 11/2 times
range in
Manufacturer
Normal
Normal
Inches
& Type Belt
Tension
Tension
3.4-4.2
Gates Hi-Power
4.4
6.6
4.4-4.6
Gates Hi-Power
4.9
7.4
5.8-8.6
Gates Hi-Power
5.8
8.7
Note: For recommendation of other types of belts,
consult respective manufacturers.
a. Shut the system down totally, disconnecting or
locking out power supply so there can be no
accidental start-up during inspection.
b. Inspect the burner carefully, including upstream
and downstream sides of mixing plates as well
as burner body face. Note that complete burner
assembly may have to be removed for proper
inspection and cleaning. Any accumulation of
scale or foreign material on either side of the
mixing plates should be removed with a wire
brush. Check visually that no holes in the mixing
plates are blocked. If any burner ports are
plugged (even partially) clear them with a piece
of wire. See Maintenance of Gas Ports.
E. Optional Coils And Related Items
1. Coils – Coil surfaces must be kept clean of dirt
and lint in order to operate at rated efficiency.
Coils should be inspected on a regular basis and
cleaned as required.
WARNING: Do not enlarge burner ports or
performance may be drastically affected.
CAUTION: Solutions used to clean coils must
not be corrosive to metals or materials
used in the manufacturer of this equipment. If
cleaning solutions are applied through means
of high pressure spray, care must be taken to
avoid damaging the coil fins. Always follow the
manufacturer’s warnings and directions for the
coil cleaner you are using.
If any mixing plates are loose or missing fasteners,
tighten/replace as necessary. Always use zinc
plated or stainless fasteners. The mixing plates
on the burner may display “hairline” cracks.
These cracks are normal, and caused by
thermal stresses occurring during combustion.
The presence of these “hairline” cracks in no
significant way affects the combustion efficiency
or performance of the heater. Should a large
opening develop, it may cause difficulties in cross
ignition of flame across the face of the burner. If
this does occur, the specific mixing plate or plates
involved must be replaced.
c. Put system back into operation and view burner
while cycling through full firing range. This will
give a visual check for blocked burner ports.
2. Condensate Drain Pan – Periodically flush the
condensate pan and drain system with a water
hose.
F. Gaskets
Gaskets are used on doors, inspection covers, some
filter racks, and some outdoor air dampers. Inspect
gaskets periodically and repair or replace as required.
G. Caulking
Inspect unit and add caulking as required.
H. Casing
Periodic cleaning of the casing is recommended to
remove dirt, grease and any corrosive substances that
may harm the finish. Rusted or corroded spots should
be cleaned and repainted.
2. Inspect the flame rod and ignition electrode for dirt
and moisture. Wipe off if necessary. Examine for
any evidence of premature arcing. If in doubt, check
continuity of flame rod to be sure it is not grounding
out. Replace if required.
The porcelain on the ignition electrode must be
intact - not cracked. The spark gap should be 1/8 of
an inch on Mestek burners.
I. Support Means
Inspect the entire unit and burner support means to be
sure everything is firmly in place.
3. Replace all access panels which have been removed
and operate the unit for a test period. Check for
normal response and function of all controls.
J. Heater
1. At least a yearly inspection is recommended
for heating installations and more frequently for
process applications in year-round operation. Your
own experience is the best guide in determining
frequency of inspection, but as a minimum the
following procedure should be followed:
4. Check all gas piping for possible leaks using a soap
bubble solution.
5. Inspect the support means to be sure that
everything is firmly anchored in place.
– 38 –
SECTION IX - MESTEK LINE BURNERS
Inspection and Maintenance of Gas Ports
Conduct initial inspection within the first month after
commissioning. Visually check the gas ports of new
burner assemblies for any piping scale or debris. Use
Pin Vise with drill bit to remove.
Use of an electric drill motor is not suggested unless
both Pin Vise and Drill can be chucked up in a varispeed drill unit. Use caution, because it is easy to snap
the bits off in a port when using a drill motor. Removal of
broken bits from the gas ports is difficult.
Annual inspections are normally adequate once
the initial piping debris is removed. The operating
conditions of the burner will determine how frequently
maintenance is actually required.
Alternate drill size which may be used is a 5/64" (for
#45).
P001117C - Mestek Line Burners
– 39 –
SECTION X - MANIFOLD AND VALVE ADJUSTMENTS
The I/O Zone 583 Controller
(UC-01) must be calling for the
burner to be enabled. The
DO-2 light will be on and Burner
Enable Relay (RE-28) needs to
be energized. This will put power
to the Burner Relay (RE-02). If
the outside air temperature is
above the Heating Economizer
65°F Setpoint the burner will
be disabled. You will need to
disconnect the plug where the
Outside Air Temperature Sensor
(TS-01) and Discharge Air
Temperature Sensor (TS-03)
are wired to the I/O Zone 583
Controller (UC-01), see High
Fire and Low Fire Adjustment
in following section. Reconnect
the plug if you are getting close
to the Freezestat lockout time,
approximately 3 minutes. To reset
the Freezestat alarm simply turn
the power off and back on at the
disconnect switch.
NOTE: A BACview or PC is
required to change settings.
See the Digital Control System
User Manual for a more detailed
sequence of operation.
Prior to setting high and low
fire you should have your test
equipment installed and be familiar
with the gas valve (VG-07) and
its adjustment, see High Fire and
Low Fire Adjustment in following
section. For High Fire Setpoint
refer to rating plate on unit for
Normal Manifold Pressure in
inches of water column. The typical
high fire flame should be blue and
approximately 12 to 18 inches long
with short orange to yellow tips.
After high fire has been set, low
fire may need to be re-adjusted.
Cycle the burner several times to
be sure it lights off reliably. Low fire
is a visual setting.
CAUTION: There should be a continuous flame along the entire
burner length without any blowout spots.
HIGH AND LOW FIRE MANIFOLD ADJUSTMENT
FOR MAXITROL VALVES WITH DDC
M611
MR212
(MR212)
(M611)
High Fire Manifold Adjustments
Note: Low fire may need to be set
first to get the burner to light off
properly.
1. Disconnect the plug where the
Temperature Sensors (TS-01
and TS-03) are wired to the
unit control module (UC-01). A
minimum of 15vdc is required at
terminals #5 and #6 on electric
relay (RE-26). This causes the
valve to call for continuous high
fire. Caution: The unit will
shut down on freezestat after
approximately 3 minutes.
2. Remove seal cap (A) and turn
regulator pressure adjusting
screw to obtain normal
manifold pressure (clockwise
rotation increases pressure).
High Fire Manifold Adjustments
Note: Low fire may need to be set
first to get the burner to light off
properly.
1. Disconnect the plug where the
Temperature Sensors (TS-01
and TS-03) are wired to the
unit control module (UC-01). A
minimum of 15vdc is required at
terminals #5 and #6 on electric
relay (RE-26). This causes the
valve to call for continuous high
fire. Caution: The unit will
shutdown on freezestat after
approximately 3 minutes.
2. Adjust the gas pressure
regulator (GP-05) to obtain the
normal manifold pressure.
Low Fire or Bypass Adjustments
1. Disconnect wire from (RE-26)
terminal #8. This causes valve
to call for continuous low fire.
2. Remove cap (B) and loosen
lock screw (C). Turn (D) to
desired low fire adjustment.
(Clockwise rotation reduces
minimum flow rate.)
3. Tighten screw (C), replace cap
(B), and reconnect wire to
(RE-26) terminal #8.
4. Reconnect the plug back into
the jack on the unit control
module (UC-01).
– 40 –
Low Fire or Bypass Adjustments
1. Disconnect wire from (RE-26)
terminal #8. This causes valve
to call for continuous low fire.
2. Remove cap (A) and turn
adjusting screw (B) to desired
low fire adjustment. (Clockwise
rotation reduces minimum flow
rate.)
3. Replace cap (A) and reconnect
wire to (RE-26) terminal #8.
4. Reconnect the plug back into
the jack on the unit control
module (UC-01).
CIRCUIT ANALYSIS – MAXITROL GAS VALVES
Connect a DC volt meter (capable of reading 0-24V DC) on the Modulator (M611) or Modulator-Regulator
(MR212) Valve terminals.
The operation of the Valve with regard to voltage is as follows: from 0 volts to approximately 5 volts, the modulating valve should be on bypass flow with the heater operating on low or minimum fire. From approximately 5 volts
to 15 volts DC, the valve should be performing its modulating function, and the heater should be firing at a modulated flow rate between low and high fire, depending upon the voltage. Above approximately 15 volts DC, the Valve
should be delivering full flow to the heater and the unit should be on full fire. If the DC voltage is obtained on the
Valve terminals, but the heater does not respond as described, the problem can be isolated to the valve itself or to
the gas control manifold of the heater.
If the proper voltages are not obtained the problem can be isolated to the electronics and/or electronic relay
(RE-26). See the Trouble Shooting Section and the Digital Control System User Manual.
See the Thermistor Output Curve in the following section.
SECTION XI - THERMISTOR OUTPUT CURVE
Typical 10,000 Ohm Thermistor Output Curve
Resistance (Ohms)
30000
25000
20000
15000
10000
5000
0
32
41
50
59
68
77
86
Temperature in Degrees F
– 41 –
95
104
SECTION XII - REPLACEMENT PARTS
Replacement parts may be ordered from the factory.
All warranty parts will be shipped freight allowed from
factory for normal ground service. Warranty parts must be
returned prepaid within 30 days. Credit will be issued if
part is complete, defective and returned on time.
When parts are ordered, MODEL NUMBER, SERIAL
NUMBER, FACTORY ORDER (F.O.) and PART NUMBERS are required. Belts, filters, and fuses are not
covered under warranty.
Dealer/Contractor Name:
Address:
City:
State:
Zip:
Ph:
SECTION XIII - RECIRCULATION
If gas fork trucks or other fossil fuel powered equipment are utilized in the conditioned area, additional
ventilation requirements for the facility must be addressed separately.
WARNING: On Heaters, which recirculate room
air, outside ventilation air must be provided in
accordance with the information shown on the
heater nameplate.
The heater inlet shall be located in accordance with
applicable building code provisions for ventilation air.
Recirculation of room air may be hazardous in the
presence of:
• flammable solids, liquids and gases
• explosive materials such as grain dust, coal dust,
gunpowder, etc.
• substances such as refrigerants or aerosols which
may become toxic when exposed to heat or flame
Field constructed intake accessories should be properly designed to minimize the entry of snow and rain.
All ventilation air to the heater shall be ducted directly
from the outdoors.
Recirculation is not recommended in uninsulated buildings where outside temperatures fall below 32°F (0°C).
Excessive recirculation or insufficient ventilation air,
which results in inadequate dilution of combustion
products generated by the heater, may create hazardous concentration of carbon monoxide, nitrogen
dioxide, and other combustion products in the heated
space.
If in doubt regarding the application, consult the heater
manufacturer.
ETL labeled recirculation heaters must be equipped
with a control system and an air measuring station
provided by the heater manufacturer and installed on
the return air damper or duct.
– 42 –
– 43 –
4830 Transport Drive, Dallas, TX 75247
Phone: 214-638-6010 Fax: 214-905-0806
www.appliedair.com