DriSteem Vapor-logic3 Operating instructions

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VAPOR-LOGIC 3
®
Microprocessor-based humidifier control system
Installation and operation manual
PLEASE: read this manual!
This manual will guide you through installation,
operation and maintenance procedures for your new
®
VAPOR-LOGIC 3 microprocessor-based humidifier
control system. Proper installation and operating
practices will ensure years of trouble-free service.
Visit our web site:
www.dristeem.com
For information about other DRI-STEEM products,
visit our web site, or contact us using the information
listed below.
For information about your humidifier tank or
dispersion unit, please see the manuals for those
specific products.
Technical support: 800-328-4447
If you have questions, first review Pages 54-70,
which describe typical problems and solutions, and
also list information you will need to give us if you
call. Our toll-free customer support line is
800-328-4447. Technicians are available from 7:30
a.m. to 5:00 p.m. (central standard time) Monday
through Friday, excluding major holidays.
Corporate headquarters
European office
14949 Technology Drive • Eden Prairie, MN 55344
952-949-2415 • 800-328-4447 • 952-949-2944 (fax)
sales@dristeem.com (e-mail)
Bell Place, Bell Lane • Syresham, Brackley • NNN13 5HP, UK
+44 1280 850122 • +44 1280 850124 (fax)
106277.1443@compuserv.com (e-mail)
Product overview
VAPOR-LOGIC 3 features overview.
®
Accurate, responsive
microprocessor control
Our newest controller, VAPOR-LOGIC3,
provides unprecedented, comprehensive control for
DRI-STEEM humidifiers. With expanded
capabilities, easy-to-use keypad, and modular, open
protocol design, the VAPOR-LOGIC3 efficiently
controls all humidifier functions.
Control mode options
•
Expected accuracies: ±5-7% RH
•
Navigating the keypad to adjust or review humidifier
functions is an intuitive process of walking through
easily-read screen menus. The controller’s openprotocol design allows seamless integration with
building management systems.
You will find no other controller in the humidifier
market able to provide such functionality, ease of
use, and accurate RH control.
On-off operating mode controls single or
multiple electric staged outputs.
Time proportioning function controls
humidifier outputs via cyclic actions on
electrical contactors or a modulated signal to
our solid state zero cross-fired SSR power
controllers.
Expected accuracies:
– Contactor action: ±2-4% RH
– SSR action: ±1-3% RH
•
Proportional action controls modulating steam
or hot water valves or GTS burners by providing
a linear analog signal to the motors (for STS,
LTS or GTS humidifiers).
Expected accuracies: ±2-5% RH
More on next page ...
Product overview:
Summary of features
1
Product overview
VAPOR-LOGIC 3 features overview.
®
Summary of features
•
PID control provides the most accurate,
responsive and adjustable relative humidity
(RH) control.
•
Self-diagnostic test at start-up
•
End of season auto-drain
•
Real-time clock allows time-stamped alarm
tracking, and three ways to program drain and
flush cycles:
1. Usage (after a set number of lbs/kg have
cycled through)
2. Usage and time (set number of lbs/kg plus
defined period of time)
3. Scheduled intervals
•
Product overview:
Summary of features
Tank temperature sensor:
– preheats tanks for uninterrupted operation
– senses for freeze protection
– senses for low water/over temperature
protection
•
Sensitivity to low-conductivity water
(important when using a standard
humidification system with low-mineral-content
water)
•
Uses Echelon’s LonTalk®, an open
communications protocol used by most major
control companies, allowing full interaction
with building management systems
•
Single-controller platform; modular design
The new VAPOR-LOGIC3 controller will soon
be standard on all DRI-STEEM humidifiers.
The base configuration includes a main
controller board and keypad. Expansion
modules will increase capability, thereby
allowing all systems to use the same controller
platform and keypad interface.
Redesigned keypad has an intuitive interface
with backlit display and provides:
– menu-driven access to all system functions
– default screen for quick view of system status
and set points
– data reports to track performance and
efficiency
– system diagnostics and alarm tracking for
troubleshooting
– single-point multiple-humidifier control
without an additional system controller
– password protection of setup parameters
– wall-mounting with a standard telephone
plate, flush mounting, or hand-held options
2
•
•
Year-2000 compliant
Product overview
VAPOR-LOGIC 3 circuit board.
®
RJ-11
Cable
keypad
RJ-45
Cable
network
Ready
water
indicator
Service
indicator
Analog
output
5/64" dia.
(6) mounting holes
Power
indicator
Water level
control input
Figure 3-1: VAPOR-LOGIC3 printed circuit board
To expansion
board (ribbon
cable)
4.228
3.548
0.312
Analog
control
inputs
Control
inputs
Control
inputs
To remote
fault indicator
(by others)
Fill
valve
Drain
valve
0.339
Outputs to
relays or
contactors
Jumper connector
R=Resistive input
I=Current input
V=Voltage input
3.523
7.047
7.671
OM-VL3-3
Product overview:
Printed circuit board
3
Product overview
Main control board connections.
®
VAPOR-LOGIC 3 main control board connections
J1 Wire terminal supplies 24 VAC to power the
VAPOR-LOGIC3 control board.
• Double terminal T1 – 24 VAC, 10 VA
maximum load
• Triple terminal T2 – 24 VAC common
J2 RJ11 female modular jack connection for supply
voltage and FTT-10A communication to
keypad/display
J3 RJ45 female modular jack connection for FTT®
10A communication to LonTalk network
J4 Wire terminal connection for FTT-10A
communication to LonTalk network. Terminals
A and B provide the communication lines. The
last terminal is earth ground.
J5 End of line communication terminator pins
J6 1/4" push-on connector for earth ground
J7 0-15 VDC analog output, typically connected to
the input of a steam or hot water valve.
Terminal 34 is the positive output signal and
terminal 35 is common.
J8 Connector receives necessary continuity input
signals from water detection devices:
• Probe system water level detection
– Terminal 30 detects maximum water level
from top probe rod and brown plug wire.
– Terminal 31 detects water level at refill
point from middle probe rod and orange
plug wire.
– Terminal 32 detects water level at its lowest
point from lower probe rod and purple plug
wire.
– Terminal 33 is the common return path for
all water detection rods from the humidifier
tank machine ground back to
VAPOR-LOGIC3 control.
• DI/RO system detection
– Terminals 30 and 31 are not used.
– Terminal 32 is connected to the humidifier
tank low water float switch (normally
open).
– Terminal 33 is the return signal from the
float switch to VAPOR-LOGIC3 control via
machine ground.
J10 Ribbon cable connector for VAPOR-LOGIC3
expansion modules
More on next page ...
4
Product overview:
Main control board connections
Product overview
Main control board connections (cont.).
Main control board connections (cont.)
Important note about J17, J18 and J19:
All connection diagrams show connector shunts
on J17, J18 and J19. The connector shunts and
appropriate software have been selected by
DRI-STEEM based on original customer orders.
Field changing the input connector shunts will
require control input modification: See Page
23 “Changing Control Input.”
J17 Jumper pins determine the configuration of the
type of input control into the RH sensor input
(terminals 21 through 23) for wire terminal
connector J26.
• R = Resistance, 0-150 ohms range
– Used with on-off humidistats, staging
switches, PE switches
– Used with analog 0-150 ohm input device
(pneumatic transducer or humidistat)
• I = Milliamp, 0-20 mA range
– Used with any humidity sensor with
4-20 mA output
– Used with any computer or energy
management system with 4-20 mA output
– Internal resistance 249 ohms, terminal 22
proportional signal, terminal 23 signal
ground
J18 Identical to J17 input selector pins except used
to configure duct high limit RH input (terminals
24 through 26) for wire connector terminal J27
J19 Identical to J17 input selector pins except used
to configure window temperature sensor input
(terminals 27 through 29) for wire connector
terminal J28
J20 Wire terminal connector supplies 24 VAC
voltage via terminals 1 and 2 to the fill valve
and via terminals 3 and 4 to the drain valve.
J21 Wire terminal connector supplies 24 VAC
voltage via terminals 5 and 6 to the power
contactor and via terminals 7 and 8 to the SDU
relay.
J22 Wire terminal connection allows for remote
fault indication. Relay closure is provided
(1 amp max.).
More on next page ...
• V = Volts DC, 0-15 volt range
– Used with any control humidistat 0-15V DC
– Terminal 21 provides positive 21 VDC
supply, terminal 22 proportional signal,
terminal 23 signal ground
Product overview:
Main control board connections
5
Product overview
Main control board connections (cont.).
Main control board connections (cont.)
J23 Wire terminal connection provides optically
isolated connection to air flow proving switch
and safety circuit. Terminal 12 supplies 24 VAC
to proving switch circuit, SPST, which closes
when air flow is present. Terminal 13 is the
return connection from the proving switch into
®
the VAPOR-LOGIC 3 control. Terminal 14
supplies 24 VAC to safety circuit, SPST, which
is closed under normal operating conditions.
Terminal 15 is the return connection from the
safety circuit into the VAPOR-LOGIC3 control.
J25 Wire terminal connector provides input for RTD
tank temperature sensor. Terminal 19 supplies 21
VDC to temperature sensor. Terminal 20 is the
return connection from the temperature sensor
into the VAPOR-LOGIC3 control. Terminal 18
has no connection.
J26 Wire terminal connector receives the necessary
signal from the controlling RH sensor.
• Terminal 21: Positive polarity 21 VDC supply
(25 mA max)
• Terminal 22: Control signal
• Terminal 23: Signal ground
• Input selector pin J17 configures J26 input
6
Product overview:
Main control board connections
J27 Wire terminal connector receives the necessary
signal from the duct high limit RH sensor.
• Terminal 24: Positive polarity 21 VDC supply
(25 mA max)
• Terminal 25: Control signal
• Terminal 26: Signal ground
• Input selector pin J18 configures J27 input
J28 Wire terminal connector receives the necessary
signal from the window temperature sensor.
• Terminal 27: Positive polarity 21 VDC supply
(25 mA max)
• Terminal 28: Control signal
• Terminal 29: Signal ground
• Input selector pin J19 configures J28 input
Product overview
Expansion board connections.
®
®
GTS and VAPORSTREAM expansion board
connections
J1 1/4" push-on connector for earth ground
J2 Blower # 2 control:
• Terminal 21: Positive polarity 21 VDC supply
(25 mA max)
• Terminal 22: Blower tachometer feedback
• Terminal 23: PWM output to blower
• Terminal 24: Common
J3 Blower # 1 control:
• Terminal 17: Positive polarity 21 VDC supply
(25 mA max)
• Terminal 18: Blower tachometer feedback
• Terminal 19: PWM output to blower
• Terminal 20: Common
J5 Ribbon cable connector for VAPOR-LOGIC®3
main controller connection
J6 Ribbon cable connector for additional
VAPOR-LOGIC3 expansion modules
J7 Wire terminal supplies 24 VAC to power the
VAPOR-LOGIC3 expansion module.
• Terminal T1 – 24 VAC, 10 VA maximum
load
• Terminal T2 – 24 VAC common
J8 Wire terminal connector supplies 24 VAC voltage
with terminal pairs 1 and 2, 3 and 4, and 5 and 6
to either contactors or GTS ignition controllers.
(Terminals 1, 3 and 5 supply the 24 VAC.
Terminals 2, 4 and 6 provide the 24 VAC
common.)
J9 Wire terminal connection provides optically
isolated connections for the gas valve feedback.
Terminals 7 and 9 provide 24 VAC and are not
used. Terminal 8 receives a 24 VAC signal back
from gas valve #1. Terminal 10 receives a 24
VAC signal back from gas valve #2.
J10 Wire terminal connection provides optically
isolated connections for the combustion air
damper limit switch, power vent pressure switch
and flue differential pressure switch. Terminal 11
supplies 24 VAC to the combustion air damper
limit switch, which closes when the damper has
opened. Terminal 12 is the return connection
from the limit switch into the VAPOR-LOGIC3
expansion module. Terminal 13 supplies 24 VAC
to the power vent pressure switch which closes
when the fan has started. Terminal 14 is the
return connection from the pressure switch into
the VAPOR-LOGIC3 expansion module. Terminal
15 supplies 24 VAC to the flue differential
pressure switch which closes when the blowers
have started. Terminal 16 is the return
connection from the differential pressure switch
into the VAPOR-LOGIC3 expansion module.
Product overview:
Expansion board connections
7
Product overview
Program code nomenclature.
Program code explained
A 14-digit VAPOR-LOGIC®3 program code appears on
the front of the control cabinet and on the wiring
diagram inside the control cabinet. The program code
specifies the parameters of the VAPOR-LOGIC3
microprocessor, which controls your humidification
system. An explanation of the program code is
detailed below.
VAPOR-LOGIC3 program code
A. Type of units:
E = English
M= Metric
B. VAPOR-LOGIC3 system type:
G = GTS®
S = STS®
L = LTS®
V = VAPORSTREAM®
M = VAPORMIST®
C = CRUV®
U = ULTRA-FOG®
N = Steam Injection
C. VAPOR-LOGIC3 board classification:
1 = One-tank system
2 = Two-tank system
3 = Three-tank system
4 = Four-tank system
5 = Five-tank system
6 = Six-tank system
D. Digital display/keypad features:
1 = Single keypad
E. Type of outputs (0-4):
0 = Steam valve/100% SSR
1 = One heat stage
2 = Two heat stages
3 = Three heat stages
4 = Four heat stages
8
Product overview:
Program code nomenclature
F. System pounds output:
##### = Output capacity
(e.g., 00285 = output capacity in lbs/hr)
G. Type of water level control:
D = DI w/ manual drain
E = DI w/ end of season drain
M = Standard w/ manual drain
A = Standard w/ autodrain
H. Operating mode:
1 = Single staged
2 = Externally staged
6 = GTS
7 = TP
8 = SSR
9 = Steam valve
I. VAV options:
V = Option present
O = Option not selected
S = SDU option
J. Temperature compensation options:
T = Option present
O = Option not selected
K. Type of humidity sensing device:
N = None, for on/off
C = 0-135 ohm humidistat
D = 6-9 VDC humidistat
H = 0-10 VDC humidistat
E = 4-20 mA humidistat
X = 4-20 mA transmitter
Q = Dew point transmitter
S = Special
Product overview
Program code nomenclature.
Program code example
E
M
1
1
1
00048
A
7
O
O
X
A. English
®
B. VAPORMIST
C. One-tank system
D. Single keypad
E.
One heat stage
F.
48 lbs/hr capacity
G.. Standard water with autodrain
H.. TP operating mode
I.
No VAV option
J.
No temp comp option
K. 4-20 mA transmitter
Product overview:
Program code nomenclature
9
Product overview
Two-year limited warranty.
DRI-STEEM Humidifier Company (“DRI-STEEM”)
warrants to the original user that its products will be
free from defects in materials and workmanship for a
period of two (2) years after installation or twentyseven (27) months from the date DRI-STEEM ships
such product, whichever date is the earlier.
If any DRI-STEEM product is found to be defective
in material or workmanship during the applicable
warranty period, DRI-STEEM’s entire liability, and
the purchaser’s sole and exclusive remedy, shall be
the repair or replacement of the defective product, or
the refund of the purchase price, at DRI-STEEM’s
election. DRI-STEEM shall not be liable for any
costs or expenses, whether direct or indirect,
associated with the installation, removal or reinstallation of any defective product.
DRI-STEEM’s limited warranty shall not be effective
or actionable unless there is compliance with all
installation and operating instructions furnished by
DRI-STEEM, or if the products have been modified
or altered without the written consent of
DRI-STEEM, or if such products have been subject
to accident, misuse, mishandling, tampering,
negligence or improper maintenance. Any warranty
claim must be submitted to DRI-STEEM in writing
within the stated warranty period.
10
Product overview:
Warranty
DRI-STEEM’s limited warranty is made in lieu of,
and DRI-STEEM disclaims all other warranties,
whether express or implied, including but not limited
to any IMPLIED WARRANTY OF
MERCHANTABILITY, ANY IMPLIED
WARRANTY OF FITNESS FOR A PARTICULAR
PURPOSE, any implied warranty arising out of a
course of dealing or of performance, custom or usage
of trade.
DRI-STEEM SHALL NOT, UNDER ANY
CIRCUMSTANCES, BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL OR
CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, LOSS OF PROFITS,
REVENUE OR BUSINESS) OR DAMAGE OR
INJURY TO PERSONS OR PROPERTY IN ANY
WAY RELATED TO THE MANUFACTURE OR
THE USE OF ITS PRODUCTS. The exclusion
applies regardless of whether such damages are
sought based on breach of warranty, breach of
contract, negligence, strict liability in tort, or any
other legal theory, even if DRI-STEEM has notice of
the possibility of such damages.
By purchasing DRI-STEEM’s products, the
purchaser agrees to the terms and conditions of this
limited warranty.
Installation
Installation checklist.
Before installing your VAPOR-LOGIC 3 control
system, review this checklist to ensure proper
installation of the product. Failure to follow the
recommendations listed below could result in failure
or damage to the humidifier or microprocessor.
‰ Attach the heater/machine ground lug in the
junction box, on the humidifier, to the subpanel
machine ground lug with the appropriate wire,
sized per equipment grounding section of The
National Electric Code.
‰ Read this manual and information before
starting.
‰ Use 2-wire, 18 gauge shield plenum
nonconduit-rated cable with drain wire for all
humidity and temperature sensor wiring. (Use
Belden Company cable #88760 or equivalent;
see wiring diagram for appropriate connections.)
®
‰ See wiring diagram and information located
inside the control cabinet door. Return all
information to the control cabinet after
installation.
‰ Position the control cabinet so that it is in sight
of the humidifier tank.
‰ Position the control cabinet so that the wire
length from the control cabinet to the
humidifier is 50 feet or less.
‰ Connect an approved electric earth ground to
the earth ground lug in the control cabinet.
‰ Never route the low voltage field control wires
near the line voltage section of the control
cabinet or in the same conduit as line voltage
wires.
‰ Never use shielded cable for water level probe
wiring.
‰ Never ground shield at sensor end. A shield
grounding lug is provided on the control cabinet
subpanel to ground the cable shielding.
‰ Keypad installation precautions:
‰ Do not locate keypad inside control cabinet.
‰ Route modular cable within control cabinet
separated from line voltage circuits.
‰ Verify that VAPOR-LOGIC3 program code,
which is detailed on Pages 8 and 9 of this
manual, matches field requirements.
‰ Follow the recommended control cabinet field
conduit knockout locations shown on the next
page as Figure 12-1.
Installation:
Installation checklist
11
Installation
Proper wiring procedures.
Proper wiring prevents electrical noise
Electrical noise can produce undesirable effects on
electronic control circuits, thereby affecting
controllability. Electrical noise is generated by
electrical equipment, such as inductive loads, electric
motors, solenoid coils, welding machinery, or
fluorescent light circuits. The electrical noise or
interference generated from these sources (and the
effect on controllers) is very difficult to define, but
the most common symptoms are erratic operation or
intermittent operational problems.
Most noise problems can be prevented by using
proper wiring practices and techniques to prevent
coupling or inducing of electrical interference into
control circuits. The following simple wiring
practices should minimize interaction of noise and
controls:
•
Connect humidifier and control cabinets to a
code-approved earth ground.
•
Separate the line voltage wiring from low
voltage control circuit wiring when routing
electrical wiring inside the control cabinet.
•
Use separate electrical conduits for line and low
voltage control wiring from the humidifier to
humidity sensors, airflow switches, etc.
More on next page . . .
Figure 12-1: Control cabinet knockout locations for power and control
Knockouts for
power wiring
Knockouts
for control
wiring
Knockouts
for heater wiring
(for VAPORSTREAM®, STS®, LTS®)
12
Installation:
Wiring techniques
OM-762
CAUTION: When making holes and
knockouts in the control cabinet, protect
all internal components from debris, and
vacuum out cabinet when finished.
Failure to comply with this warning may
damage sensitive electronic components
and void the DRI-STEEM warranty.
Installation
Proper wiring procedures (cont.).
Proper wiring prevents electrical noise (cont.)
•
•
Do not use chassis or safety grounds as currentcarrying commons. No safety grounds should
ever be used as a conductor or neutral to return
circuit current.
When wiring external electrical connections to
humidistats, room/duct humidity and
temperature transmitters, or control signal input
connections from a building control system, use
18-gauge (minimum) plenum-rated twisted-pair
wire, Belden #88760, with cable shielding and
drain wire for grounding.
•
Return all shielded cable connections to the
control cabinet for grounding. Do not ground
shield at the device end.
•
IMPORTANT: Locate the control cabinet
so that wire lengths are 50 feet or less to the
humidifier.
•
Use 18-gauge stranded wire run in conduit (see
Figure 13-1) for probe and low-water cut off
wiring.
•
IMPORTANT: Do not use shielded cable
for probe wiring.
Figure 13-1: Probe wiring
Brown (full) top probe rod Level A
Orange (refill) middle probe rod Level B
Violet (low water) bottom probe rod Level C
or DI model low-water cutoff switch
OM-VL3-11
Probe wiring to be
18-gauge stranded
wire run in conduit
independent of line
voltage wiring.
Do not use shielded
cable for probe
wiring.
Installation:
Wiring techniques
13
Installation
Control cabinet installation and wiring.
®
The VAPOR-LOGIC 3 control board is shipped
mounted with all internal wiring completed within a
control cabinet. All software has been custom
programmed into your VAPOR-LOGIC3 system
according to the original order requirements.
•
VAPOR-LOGIC3 is powered by a low voltage
Class 2 control transformer. The transformer
provides a 24 VAC supply, and is protected by
an integral manual reset circuit breaker.
•
Follow field wire torque requirements shown on
the humidifier wiring diagram when connecting
the power and control wiring inside the
humidifier control cabinet.
•
Use only a 1/8" straight blade screwdriver on
VAPOR-LOGIC3 control board terminal blocks.
•
Use a single 18-gauge pre-tinned wire in each
terminal at the VAPOR-LOGIC3 terminal block.
Torque to 5 inch-pounds.
•
When terminating multiple wires to the
VAPOR-LOGIC3 control board terminal block,
secure the multiple wires and one
additional wire with an appropriately sized wire
nut. Use the single additional wire's opposite
end to connect to the VAPOR-LOGIC3 terminal
block.
•
Never run the control system wires bundled
with, or in the same conduit as, power wires.
Important control cabinet installation points:
•
All humidifier power wiring is represented on
the humidifier wiring diagram located with an
installation guide on the inside of the control
cabinet door. Return all instructions to the
control cabinet after installation.
•
Refer also to the VAPOR-LOGIC3 control
board drawing on Page 3 of this manual for
detail of the board and connection points.
•
Pick a location within sight of the humidifier
tank that will allow for easy access to the
control cabinet and internal electrical
components.
IMPORTANT: Locate the control cabinet
so that wire lengths are 50 feet or less to the
humidifier.
14
•
Mount control cabinet using the mounting tabs.
•
Always wire the VAPOR-LOGIC3 control
board per local and national electric codes.
Installation:
Control cabinet installation and wiring
Installation
Keypad/display installation.
Installing modular cable
Installing the keypad/display
IMPORTANT: When routing modular cable
inside the control cabinet, route cable away from all
power wiring and connect the male modular plug into
®
the VAPOR-LOGIC 3 printed circuit board-mounted
female modular receptacle, J2. Push male plug in
until you hear a “click.” (The cable should be
plugged into the keypad/display as well.) The sixwire cable provides the AC power to the keypad/
display and completes the FTT-10A-type digital
communication between the keypad/display and the
VAPOR-LOGIC3 control board.
IMPORTANT: Do not locate the keypad/display
inside the control cabinet. The hardware is
premounted in the keypad/display case with front
access to the digital display and keypad. Position the
case in a convenient location for easy access.
CAUTION: If a longer cable is needed, do not
attempted to fabricate one. Improper wiring can
permanently damage the VAPOR-LOGIC3 board,
keypad or display. Please contact your local
DRI-STEEM representative for longer cable options.
Note that the keypad/display requires an ambient
temperature range of 32°F to 122°F (0°C to 50°C) to
operate properly. Exceeding these limits will result in
a poor reading or no reading at all.
We recommend that you mount the keypad/display to
a surface using a field-supplied network phone wall
plate. To mount, simply slide the keypad/display onto
the tabs on the phone plate.
Installation:
Keypad/display installation
15
Installation
Sensing devices and humidity control.
16
Important to properly place sensing devices
Other factors that affect humidity control
Humidity sensing devices must be properly placed to
achieve accurate humidity control. A typical small air
handling system is shown in the drawings on Pages
17 and 18 (Figures 17-1 and 18-1). For the best
control, place the humidity sensing device in the
center of a room, or just inside the return air duct
(location “A”). These locations will provide the least
amount of variation caused by air flow patterns and
room temperature. Placement of the duct humidity
sensing device within the outlet of the air handler
(location “D”) is ideal for duct high limit control, but
the actual placement must be downstream from
dispersion tubes a sufficient distance to ensure steam
absorption has taken place. Accurate control of
temperatures in rooms and ducts is also very
important to improve control of relative humidity.
Unsatisfactory humidity control may involve more
than just the controller’s capability to control the
system. Other factors that play an important role in
overall system control are:
Installation:
Sensing devices and humidity control
•
Size of the humidification system relative to
load
•
Overall system dynamics associated with
moisture migration time lags
•
Accuracy of humidistats and humidity
transmitters and their location
•
Dry bulb temperature accuracy in space or duct
•
Velocities and air flow patterns in ducts and
space environments
•
Electrical noise or interference
Installation
System Diagram.
Figure 17-1: System diagram
Line voltage
ULTRA-SORB®
dispersion unit
Liquid level detectors
Electrical supply
Keypad/display
24 volt
Line voltage
Control cabinet
OM-3007
VAPORSTREAM®
VLC humidifier
Installation:
Component placement
17
Installation
Placement of sensing devices.
Figure 18-1: Recommended sensor locations
A
Best
B
Alternative location
C
Not recommended
D
Best duct high limit humidistat
High limit humidistat
or high limit transmitter
(set at 90% RH max.)
placement for VAV
applications
10' min.
(3 meters)
Outside air
Return air
Relief air
B
AHU
(Air handling unit)
D
Air flow switch
(sail type
recommended
for VAV
application)
Vapor absorption
has taken place
Point of vapor
absorption
B
B
C
A
A
B
North or northeast
facing window
OM-3008
Temperature compensation transmitter
located on lower corner of the inside
surface of double pane window glass
18
Installation:
Placement of sensing devices
Humidifier tank
Installation
Wiring of sensing devices.
Wiring on-off humidistats
DRI-STEEM provides three types of on-off controls:
wall-mounted humidistat, duct-mounted humidistat,
or pneumatic/electric relay. The wiring diagram
(found on the inside of the humidifier control
cabinet) will show proper wiring for these controls.
Wiring modulating humidistats
The signal from a humidistat directly controls the
amount of output from the humidifier. The standard
modulating humidistat controllers DRI-STEEM
provides are either duct or wall-mounted.
The humidistats are powered by a 21 VDC supply
®
provided by the VAPOR-LOGIC 3 control board. A
variable control signal is returned to provide the
modulating function on the humidifier.
For a pneumatic modulating signal, DRI-STEEM
may provide a transducer, which accepts a 3-20 psi
pneumatic input range.
Wiring modulating humidity
or temperature transmitters
Transmitters provide an analog signal proportional to
the process variable being measured. All transmitters
provided by DRI-STEEM are two-wire devices. (See
your wiring diagram for proper connections.) The
humidity transmitters have a range of 0-100% RH
with an output of 4-20 mA. The temperature
transmitter has a range of -20° to 160°F
(-29° to 71°C) with a 4-20 mA output.
Calculation of transmitter % RH
% RH = (milliamp reading minus 4)
.16
Example:
12 mA - 4 = 50%
.16
Installation:
Wiring of sensing devices
19
Installation
Wiring of sensing devices.
Figure 20-1: Example of proper shielding techniques when
®
connecting humidity or temperature devices to VAPOR-LOGIC 3 control inputs
Note: The wiring diagram (found on the inside of the
humidifier control cabinet) will show the proper controls
wiring.
OM-VL3-17
IMPORTANT: Consult control cabinet wiring diagram. Control changes require wiring and programming changes.
20
Installation:
Wiring of sensing devices
Installation
Wiring VAV sensing device.
Variable air volume (VAV) option
This option is identified as a “V” in the third-from-last
place of your program code nomenclature (for
example: EV11400285A7VOX).
When the VAV control option is requested we provide
a duct mounted humidity transmitter (4-20 mA output
over 0-100% RH range). Install using shielded cable
(see Figure 21-1 below).
The modulating high limit transmitter signal operates
in conjunction with the room or duct controlling
®
transmitter signal through the VAPOR-LOGIC 3
control system to prevent over humidification in the
duct work. VAPOR-LOGIC3 will start lowering the
humidifier output when the duct relative humidity is
within six percent of the duct high limit set point.
When this occurs, the keypad/display will show the
message “VAV output limit.” If necessary, the
reduction of the humidifier output will continue until
maximum high limit set point has been reached,
shutting off the humidifier completely.
When the high relative humidity starts to decrease in
the duct, VAPOR-LOGIC3 will slowly start to
increase the production of steam vapor. When the
duct relative humidity decreases to a point greater
than six percent below the duct high limit set point,
the control transmitter will be restored as the primary
controller and the keypad/display will no longer
show the “VAV output limit” text, returning the
control system to normal operation.
Figure 21-1: Shielded cable
OM-VL3-18
NOTE: Ground shield at control panel end only.
Do not ground shield at device end.
Installation:
Wiring VAV sensing device
21
Installation
Temperature compensation transmitter.
Temperature compensation offset option
This option is identified as a “T” in the second-fromlast place of your program code nomenclature (for
example: EV11400285A7OTX).
The transmitter provided with VAPOR-LOGIC3 is
calibrated for -20°F to 160°F (-29°C to 71°C) with
output from 4-20 mA. For example, a temperature
reading of 70°F should produce a measurement of
12 mA.
When selected as an option, DRI-STEEM provides a
temperature compensation (temp comp) transmitter.
The temperature compensation transmitter
continually monitors the interior window glass
temperature and transmits this temperature to
®
VAPOR-LOGIC 3. VAPOR-LOGIC3 then compares
the glass temperature to the desired RH set point in
the humidified area and calculates the dew point (°F)
for the space.
Install using an 18-gauge plenum-rated shielded
cable for transmitter wiring with grounding shield at
the shield ground lug in the control cabinet (see
Figure 21-1 on the previous page).
VAPOR-LOGIC3 will lower (offset) the desired RH
set point so that moisture does not form on windows.
The keypad/display will show the amount of offset
that has taken place as a modified set point. As the
interior window glass temperature increases,
VAPOR-LOGIC3 will reduce the offset and restore
system control to the normal RH set point for the
space.
See Figure 22-1 below.
Temperature compensation
transmitter placement
1.
Position the temperature compensation
transmitter control box on a wall adjacent to a
window frame facing north or northeast.
2.
Place flat surface of temperature sensor tip on
lower corner of glass surface.
3.
Temporarily hold the sensor tip in place with
strips of masking tape.
4. Apply a small amount of clear RTV silicone
adhesive over and around the sensor tip (making
sure the sensor tip is in contact with the window
glass).
Figure 22-1: Temperature compensation
transmitter placement
5.
Window
framing
Thermostat
control wires
Surface-mounted
thermostat
Typical
temperature
sensor
control
cord routing
box on wall
Double
pane
window
glass
Secure temperature
sensor tip to inside
surface of window glass
using clear RTV silicone
adhesive
OM-337
22
Installation:
Temperature compensation transmitter
After adhesive has cured, remove masking tape.
Installation
Changing control input.
Changing control input
4.
Change the last character in the configuration
string to the desired input signal type identified
from the program coded nomenclature
information on Pages 8 and 9.
5.
Adjust the shunt connector J17 to the proper
signal type, if necessary:
®
VAPOR-LOGIC 3 has the ability to accept different
types of demand signals from either an energy
management system or a humidistat. Follow these
steps when a signal change is needed:
1.
Remove the old signal wires from the board
(terminals 21, 22 and 23).
2.
Refer to program code nomenclature on Pages 8
and 9. Refer to: “K. Type of humidity sensing
device” to identify the new signal that is needed.
3.
Enter the “Set Up” screen on the
VAPOR-LOGIC3 keypad and scroll to the
“Configuration String” screen.
– If the signal is current, the jumper should be
on I.
– If the signal is voltage, the jumper should be
on V.
– If the signal is resistance, the jumper should
be on R.)
6.
Connect the new signal to the board.
Installation:
Changing control input
23
Operation
Start-up checklist.
Note:
Your humidification system may not have all
of the options listed below. If an item does not
appear, skip to the next item and continue the
process.
‰ Verify that wiring is done per instructions in this
manual and the unit wiring diagram.
‰ Make sure that the keypad/display is not inside
the control cabinet.
‰ Check water level control voltages. The reading
should be 2.5 VAC without water; and 0 VAC
with water from ground (Pin 33-J8) to probe
inputs (Pins 30, 31 and 32-J8).
‰ Check the proportional band setting in the
“System Set Up” menu of the keypad/display
(default is 10%).
‰ Check the cycle setting in the “System Set Up”
menu of the keypad/display (default is 60
seconds; 2 seconds for SSR).
‰ Check the proportional gain setting in the
“System Set Up” menu of the keypad/display
(default is 80).
‰ Check the integral gain setting in the
“System Set Up” menu of the keypad/display
(default is 40).
‰ Check the derivative gain setting in the
“System Set Up” menu of the keypad/display
(default is 0).
‰ Check drain duration (default is 8 minutes).
‰ Check flush duration (default is 8 minutes).
‰ Check RH setting.
‰ Check control signal.
‰ Check amp draw of heaters for electric units;
refer to wiring diagram for proper rating. If unit
is powered by steam, check for steam flow. For
gas fired units, verify gas flow and combustion.
‰ Confirm that the control signal being connected
®
to the VAPOR-LOGIC 3 system is compatible
with the VAPOR-LOGIC3 program. Identify the
VAPOR-LOGIC3 program code on the wiring
diagram or on the outside of the control cabinet
door. Refer to the VAPOR-LOGIC3 manual to
decipher the code using the nomenclature
description on Pages 8 and 9.
More on next page ...
24
Operation:
Start-up checklist
Operation
Start-up checklist (cont.).
‰ Confirm that all wiring is correct per the wiring
diagram.
‰ Confirm that proper grounding and an approved
earth ground are provided.
‰ Confirm that the J17, J18 and J19 shunt
®
connectors on the VAPOR-LOGIC 3 board are
in their correct position per the wiring diagram.
See Page 3 for the physical locations.
‰ Confirm that the keypad/display is mounted on
the outside of the control cabinet with modular
cable routed away from high voltage circuits
and connected to the J2 female connector on the
control board.
‰ Turn water supply on and confirm that the drain
valve (if available) is closed.
‰ Turn power on and confirm that the display
shows the “Main Menu” screen with an
operational clock.
‰ Enter the “Control Modes” screen and make
sure the system is in auto mode.
‰ When the keypad/display shows “Filling” as
part of the idle screen information, confirm that
the tank is filling with water.
‰ Confirm that the airflow switch is closed.
‰ Confirm that the high limit humidistat input is
closed or that the variable air volume (VAV)
control system high limit transmitter is
connected.
‰ With sufficient water in the tank, the air flow
switch closed, the high limit humidistat closed,
the safety interlock circuit closed, and a call for
humidity, verify that the heat outputs are
activated.
IMPORTANT: Confirm that the tank has
sufficient water. If the tank does not contain
water and the heat outputs are activated, or the
burners are fired by the VAPOR-LOGIC3
control system, a serious failure will result. If
this happens, immediately remove power from
the system and verify that all wiring is done per
the wiring instructions in this manual and the
unit wiring diagram.
‰ During normal operation, the keypad/display
will show humidifier operating status. See Pages
27 through 36 for descriptions of keypad/
display menu items. To change any of the
operating parameters, please refer to the above
pages.
‰ If you experience difficulties, have the above
information available with the model and serial
numbers of the humidifier and the
VAPOR-LOGIC3 program code and call
DRI-STEEM for help.
Operation:
Start-up checklist
25
Operation
Keypad/display overview.
Components of the keypad/display
®
The VAPOR-LOGIC 3 keypad/display consists of
(see Figure 26-1 below):
•
•
•
•
A 128 x 64-pixel backlit LCD display
A power light
An alarm light
Eight keys:
– Four arrow keys
– An Enter key
– Three soft keys
A soft key’s function is determined by the screen
currently displayed.
The arrow keys are used to adjust the values of the
different parameters of the humidifier.
The Enter key is used to make selections on various
screens.
The power light is illuminated whenever power is
applied to the keypad/display.
The alarm light is activated any time a fault condition
is detected.
Figure 26-1: VAPOR-LOGIC3 keypad/display
26
Operation:
Keypad/display overview
The menu system
The VAPOR-LOGIC3 keypad/display software
organizes the control of the humidification system
under six top-level screens:
•
•
•
•
•
•
Status
Control Modes
Alarms
Set Up
Diagnostics
Reports
Each one of these screens is used to view or modify a
different characteristic of the humidifier. To access
any of these screens, activate the Main Menu of the
keypad by depressing the “Main” soft key whenever
it is visible. This will immediately take you to the
Main Menu selection screen, allowing you to choose
where you would like to go next using the up and
down arrow keys followed by the Enter key. The
menu structure is diagramed on the opposite page,
with a brief description of the submenus on the pages
following.
Operation
VAPOR-LOGIC 3 menu structure.
®
Main Menu
1) Status
Soft key) Main – Returns to the Main Menu screen
Soft key) Back – Scrolls to the previous Status item
Soft key) Next – Scrolls to the next Status item
2) Control Modes
1) Auto Mode
2) Test Mode
3) Manual Drain
4) Standby
Soft key) Main – Returns to the Main Menu screen
Soft key) Idle – Switches display to the Idle screen
3) Alarms
Soft key) Main – Returns to the Main Menu screen
Soft key) Acknlg – Acknowledges the selected Alarm
Soft key) Clear – Clears the selected Alarm
4) Set Up
Soft key) Main – Returns to the Main Menu screen
Soft key) Back – Scrolls to the previous Set Up item
Soft key) Next – Scrolls to the next Set Up item
5) Diagnostics
Soft key) Main – Returns to the Main Menu screen
Soft key) Back – Scrolls to the previous Diagnostics item
Soft key) Next – Scrolls to the next Diagnostics item
6) Reports
1) H2O Converted
2) Energy Used
Soft key) Main – Returns to the Main Menu screen
Soft key) Idle
Soft key) Main – Returns to the Main Menu screen
Soft key) Control – Switches display to the Control Modes screen
Soft key) Alarms – Switches display to the Alarms screen
Operation:
Menu structure
27
Operation
“Set Up” menu information.
“Set Up” menu
readout
“Set Up” menu
description
Range
Default
RH Set point
RH Offset
Dewpoint Set point
Dewpoint Offset
PID Band
Kp
Ki
Kd
Duct High Lim RH
RH Offset
Temp Comp Offset
ADS Mode
Relative humidity set point
RH offset calibration
Dew point set point
Dew point offset calibration
PID loop modulation band
Proportional gain factor
Integral gain factor
Derivative gain factor
Duct high limit RH set point
Duct RH offset calibration
Temp comp sensor calibration
ADS operating mode
35%
0%
50°F/10°C
0°F/0°C
10%
80
40
0
80%Duct
0%
0°F/0°C
Use
Lbs of H20 until ADS
Lbs/kg of water
that must be boiled
for ADS to start
Day to start ADS sequence
Current day of the week
Hour to start ADS sequence
20-80% RH
±20% RH
20-80°F/-7-27°C
±20°F/±20°C
1-20% RH
1-1000
0-1000
0-1000
50-95% RH
±20% RH
±20°F/±20°C
Use
Use + Interval
Interval
6-32,767 lbs/
3-14,863 kg
Sunday - Saturday
Sunday - Saturday
0-23
(midnight–11:00 p.m.)
0-180 days
1
1
0
7 days
Skim time duration
Cycle time
0-120 minutes
0-15 minutes
100-3,276,700 lbs/
100-1,486,300 kg
0-120 seconds
30-99 seconds
8 minutes
8 minutes
System
dependent
3 seconds
60 seconds
Cycle time
1-30 seconds
2 seconds
1-30 minutes
40-180°F/4-82°C
1-168 hours
2 minutes
40°F/4°C
72 hours
0-32767
(0 = password disabled)
System dependent
0
Configuration String
SDU delay duration
Aquastat set point
Inactivity time until EOS
drain cycle starts
Password required to
enter the “Set Up” screen
See program code nomenclature
Real Time Clock
Clock and date settings
N/A
ADS Day
Today
ADS Hour
ADS Interval
ADS Duration
AFS Duration
Service Setpoint
Skim Duration
Heater Cycle Time
(TP-type control)
Heater Cycle Time
(SSR-type control)
SDU Duration
Aquastat
Inactivity Until EOS
Set Up Password
28
Number of days
between ADS cycles
Autodrain sequence duration
Auto flush sequence duration
Service interval set point
Operation:
“Set Up” menu information
System
dependent
System
dependent
Current
date/time
Operation
Keypad/display readouts.
Readout displayed
Description
Filling
The unit is filling with water.
Skimming
The unit has completed a fill cycle and is now skimming.
Draining
The unit is draining.
Flushing
The unit is flushing.
No Duct Air Flow
The air flow proving switch is open.
Interlock Disable
The interlock circuit is open.
VAV Output Limit
The unit is approaching or has reached the duct RH high limit set point.
Preheating Tank
The unit has received a call for humidity and is preheating the tank.
Freeze Protection
The tank temperature has fallen below the aquastat set point and the unit
is being heated.
End of Season Drain
The unit is in end of season drain mode.
End of Season
The unit is in end of season.
Low Tank Level
The water level is below the probes on a standard water unit or below
the float on a DI/RO water unit.
Temp Comp
The RH set point has been temporarily modified to prevent moisture
from forming on the windows. The modified set point is identified with
an asterisk.
Duct RH High Limit
The duct high limit RH has been reached.
Service Humidifier
It is time to perform routine service on the humidifier.
Replace Probes
The system has detected the need to clean or replace the probe
rod assembly.
Operation:
Keypad/display readouts
29
Operation
Main menu: 1) Status.
Status
The Status screen is used to view some of the
operating parameters of the humidification system.
Some of the parameters that may be displayed
include:
30
•
RH setpoint
•
Room RH
•
Dewpoint setpoint
•
Measured dewpoint
•
Duct setpoint
•
Duct RH
•
Window temp
•
System demand (%)
•
System output (pounds/hour or kilograms/hour)
•
Tank temp (°F or °C)
•
Water until ADS
•
Water until service
Operation:
Main menu: 1) Status
Operation
Main menu: 2) Control Modes.
Control Modes
In the Control Modes screen, the operational mode of
the humidifier can be set. You may choose from auto,
test, manual drain or standby.
In Auto Mode, the humidifier operates normally. All
inputs and outputs are monitored and controlled. If
there is a call for humidification, the system will
react.
In Test Mode, the controller sequentially cycles
through all outputs so that their operation may be
confirmed. Once all outputs have been cycled on and
off, the controller reverts to the Standby Mode.
In Manual Drain Mode, the automatic drain valve
(if so equipped) is opened and the tank is drained. All
humidifier operation is suspended and the drain valve
is held open until the unit is taken out of Manual
Drain Mode.
In Standby Mode, the humidification system is
taken off line. All humidity control inputs are
displayed but not acted upon.
To select a new mode, use the vertical arrow keys to
move the selection pointer on the left hand side of the
screen up or down. When the pointer is positioned
next to your new selection, press the Enter key. Your
new selection will now appear as inverted text.
Note that the current mode of the humidifier is
always shown as inverted text on this screen.
Operation:
Main menu: 2) Control Modes
31
Operation
Main menu: 3) Alarms.
Alarms
The Alarms screen is used to view the alarm log. Use
the vertical arrow keys to scroll through the alarm
log. The alarm log contains a record of the previous
10 faults that have occurred on the humidifier. The
alarms may either be acknowledged or cleared using
the soft keys below the display. If an alarm is
acknowledged, it will be cleared and left in the log
for future reference. If an alarm is cleared, it will be
cleared and removed from the log.
32
Operation:
Main menu: 3) Alarms
Operation
Main menu: 4) Set Up.
Set Up
In the Set Up screen, the operational parameters of
the humidifier can be set. Depending on system
options, parameters available may include:
•
RH setpoint
•
RH offset
•
Dewpoint setpoint
•
Dewpoint offset
•
Duct high lim RH
•
Duct RH offset
•
Temp comp offset
•
PID band
•
PID gains (Kp, Ki, Kd)
•
ADS mode
•
Lbs of H2O until ADS
•
ADS day
•
Today
•
ADS hour
•
ADS interval
•
ADS duration
•
AFS duration
•
Inactivity until EOS
•
Service setpoint
•
Water until service
•
Heater cycle time
•
Skim duration
•
SDU duration
•
Aquastat
•
Configuration string
•
Date/Time set
•
Set up password
To modify a value, use the Next and Back soft keys to
locate the parameter in need of modification. Once the
parameter has been located, use the vertical arrow
keys (or + and - keys) to change values, and use the
left and right arrow keys to move to different place
holders. When you are finished, you must press
either the Next or Back soft keys, or the Enter key
to save your change. If you press the Main soft key
without first pressing one of these other keys, your
modification to that particular parameter will be lost.
Operation:
Main menu: 4) Set Up
33
Operation
Main menu: 5) Diagnostics.
Diagnostics
The Diagnostics screen enables you to troubleshoot
some of the hardware input and output points of the
®
VAPOR-LOGIC 3 control system. The soft keys Next
and Back are used to move through the diagnostic
options. Once you have found the item you would
like to troubleshoot, view the reading and compare it
with what the value should be.
For example, if you were going to troubleshoot the
RH signal input, you would select RH Signal on the
Diagnostics screen. The display would then tell you
what the current input signal is in mA. It would also
tell you what this voltage translates to in terms of
relative humidity. You can then verify that the input is
working correctly.
34
Operation:
Main menu: 5) Diagnostics
Depending on system options and type, diagnostics
available may include:
•
RH input
•
Demand input
•
Dewpoint input
•
Duct HL input
•
Temp comp input
•
High probe voltage
•
Mid probe voltage
•
Low probe voltage
•
DI float
•
Tank temp input
•
Air flow switch
•
Safety interlock
•
Blower #1 RPM
•
Blower #2 RPM
•
Burner #1 gas valve
•
Burner #2 gas valve
•
Combustion air switch
•
Power vent switch
•
Flue differential pressure switch
Operation
Main menu: 6) Reports.
Reports
The Reports screen is useful for viewing historical
information about your humidifier. In this section,
you are able to view the amount of water that has
been used by your humidifier and the amount of
energy it has consumed.
Operation:
Main menu: 6) Reports
35
Operation
Main menu: Idle screen.
Idle Screen
The Idle screen allows you to monitor the
humidifier’s basic operation. Depending on system
options, you may view system set point, the actual
space condition and the system demand.
The top line of the display informs you of the current
mode of the humidifier.
The second line is a system status line. This line will
continuously scroll through any system status items
that are currently present. This may include
(depending on your system’s options) Filling,
Skimming, No Duct Air Flow, High Limit Disable,
etc. The soft keys in this mode provide quick, direct
access to the Control Modes screen, the Alarms
screen or back to the Main Menu screen.
36
Operation:
Main menu: Idle screen
Operation
Control modes.
On-off control
Demand signal control
On-off control is the simplest control scheme, and
does exactly what its name implies: the output device
turns fully on, then fully off.
With demand signal control, the VAPOR-LOGIC3
controller provides the output level that a master
control signal calls for. This signal can either be
generated by a humidistat or by a building energy
management system. The signal that is sent to the
VAPOR-LOGIC3 board is a modulating signal
(typically 4-20 mA or 0-10 VDC). The board
responds to this signal by producing a directly
proportional output. In other words, with a
4-20 mA signal, a command of 4 mA would produce
no output. A command of 12 mA would have the
humidifier running at 50% capacity, and a command
of 20 mA would have the humidifier running at
100% capacity. With a humidistat provided by
DRI-STEEM providing this signal, the humidity set
point is set at the humidistat. The keypad/display is
then used for maintaining and troubleshooting the
humidification system, with humidifier control
stemming from the humidistat itself. With an energy
management system (EMS) providing the signal, the
humidity set point is established somewhere on the
EMS and the humidifier responds to the EMS
commands.
The on-off humidistat differential is designed into the
control action between the on and off switching
points. The differential is established at a range
sufficient to prevent output short-cycling. In other
words, the humidity level will have to fall a little
below set point before the humidistat will close and
energize the humidifier. Once the humidifier is
energized, the humidistat will stay closed until the
humidity is a little above set point. This creates an
operating range that prevents the humidifier from
running for very short periods of time.
This type of operation is applicable to all
DRI-STEEM humidification systems controlled by
®
VAPOR-LOGIC 3. In applications where there are
multiple contactor outputs, such as a
®
VAPORSTREAM , the contactors for the different
heat stages are pulled in one at a time with a two
second interval between them. In applications with a
®
®
variable output stage, such as an STS or GTS , the
outputs are ramped up until they reach 100%.
Transmitter control
With transmitter control, the VAPOR-LOGIC3 board
receives a linear signal that corresponds to the actual
humidity level being measured. (With a
DRI-STEEM-provided transmitter, the signal is
4-20 mA, which corresponds with 0-100% RH.) The
VAPOR-LOGIC3 controller then uses this humidity
measurement, along with a user defined desired
humidity set point, and calculates a demand level.
This demand level is the level at which the
humidifier will run.
Operation:
Control modes
37
Operation
Modulation types: TP modulation.
TP modulation
The standard form of modulation with an electric
humidifier is TP (time-proportioning) modulation.
With this type of modulation, the outputs are cycled
on and off at a certain rate to approximate humidifier
demand.
®
For example, if a VAPORSTREAM humidifier has
four heat output stages (four contactors) and a
demand of 55%, two of the contactors will be
energized all of the time, one contactor will be
cycling on and off at a certain rate, and one contactor
will be off all of the time. The rate at which the third
contactor cycles is determined by the demand and the
TP cycle time. Continuing with our example, if we
have a TP cycle time of 60 seconds and a demand of
55%, the third contactor will be cycling at a rate of
12 seconds on and 48 seconds off.
To calculate the above example, imagine that each
contactor represents 25% of the output of the
humidifier. With a 55% system demand, we need two
full contactors plus 5/25 of a third contactor.
Therefore, two contactors will be full on and a third
contactor will be on for 5/25 of 60 seconds, or 12
seconds.
38
Operation:
TP modulation
To minimize wear on the contactors that are cycling,
®
VAPOR-LOGIC 3 keeps track of the number of
cycles on all contactors and it will rotate the TP
cycling contactor through the stages to ensure that
they all get equal wear. In addition, no contactor will
ever have a cycle time of less than two seconds or
greater than two seconds less then the TP cycle time.
In other words, if a contactor needs to be on for less
than two seconds because of the way the math turns
out, the contactor will be energized for the minimum
two second period. Also, if a contactor needs to be
de-energized for less than 2 seconds, it will stay on.
This prevents quick cycling of the contactors and
extends their life. On a TP system with contactors,
the TP cycle time is user-adjustable and can be set
from 30 seconds to 99 seconds via the
VAPOR-LOGIC3 keypad/display.
Operation
Modulation types: SSR modulation.
There are two basic types of SSR modulation: SSR
modulation with contactors, and 100% SSR
modulation.
SSR modulation with contactors
With SSR modulation with contactors, the operation
of the unit is the same as it is with TP Modulation. In
this scenario, one of the cycling contactors is
replaced with an SSR. The SSR is now the device
that carries out all of the cycling duties. The
contactors will always be either on or off. Any TP
cycling that is needed will be handled by the SSR
stage.
This provides two distinct advantages over standard
TP modulation. First, an SSR can turn on and off
much faster than a contactor can. Therefore, as the
unit modulates around a demand signal, tighter
control is achieved because the cycle time on an SSR
system is factory-set at one second. This means that
every second, the controller can adjust the on and off
times on the SSR to very closely track the desired
demand.
100% SSR modulation
The ultimate in electric humidifier modulation is 100%
SSR Modulation. With this type of control, all heat
stages are controlled by SSRs. This allows the output
of the humidifier to track the actual demand very
closely because all heat stages can now cycle on and
off at the rapid SSR cycle rate.
With 100% SSR modulation, a contactor is still
provided in series, with the SSR device as an
additional safety feature. This contactor is energized
any time there is demand on the humidifier, and
remains energized until the demand is satisfied. In
this way, if there is a failure in the SSR device, the
contactor is there as a backup to shut the humidifier
down.
The second major advantage over standard TP
modulation is reliability. With a solid state device
like an SSR, component wear and tear is almost
nonexistent when compared with an
electromechanical device such as a contactor.
Therefore, with the SSR doing all of the heavy
cycling work, the life expectancy of the contactors is
extended.
Operation:
SSR modulation
39
Operation
Modulation types: valves and burners.
®
®
®
STS , LTS and ULTRA-FOG valve modulation
With a valve system, the modulation is very simple.
The demand signal simply determines how far the
valve is going to open. In other words, if the system
demand is 25%, the valve will be open 25%.
®
GTS burner modulation
The burner modulation technique used on a GTS is
probably the most complicated. The burners can
operate anywhere from 25% to 100% of their
capacity. To accomplish this turndown, the blower
®
speed is varied by the VAPOR-LOGIC 3 controller.
(The blowers used on the GTS are variable speed
blowers with a tachometer feedback. The
VAPOR-LOGIC3 controller monitors this feedback
and uses it, in conjunction with the demand signal, to
control the blower speed.) As the blower speed
varies, the gas valve automatically adjusts the amount
of gas being introduced into the burner. This variable
combination of gas and air results in clean
combustion in the range of 25-100% of burner
capacity.
When individual burner demand falls to below 25%
of capacity, the operation changes. Basically, a oneburner GTS has full modulation in the range of
25-100%. Below 25%, the unit essentially time
proportions. A two-burner GTS has full modulation
in the range of 13-100%. Below 13%, the two-burner
unit will time proportion.
To explain this, lets first look at the operation of a
one-burner GTS. As the demand on the unit increases
from 0, the unit will remain off until the demand
reaches 14%. Once 14% demand is reached, the
controller will fire the burner and run it at 25% of its
rated capacity. (When a GTS burner fires, it fires at
72% of its rated capacity. If the tank is warm, then it
immediately modulates up or down to the desired
demand. This is done to provide the smoothest,
quietest, most reliable ignitions. If the tank is cold,
the unit will run at 100% capacity to preheat the tank.
Once the tank is hot, it will resume normal
operation.) The lit burner will stay at 25% of its rated
capacity unless the demand on the system exceeds
40
Operation:
Valve and burner modulation
25%. At this point, the burner output will exactly track
with the demand. In other words, if the demand on the
system is 55%, the burner will be running at 55%
output. As the system demand drops down below
25%, the burner will continue to run at 25% until the
system demand drops to 11%. At this point, the
burner will be shut down. The controller will not fire
the burner again until the demand goes back to 14%
or higher. Then, the burner will again fire and run at
25% of its rated capacity. What this results in is a
modified time proportioning system for a system
demand below 25%, and exact demand tracking for
any system demand over 25%.
A two-burner GTS operates in much the same way
with a few slight differences. As demand increases
and reaches 8%, one of the burners will fire and run
at 25% of its rated capacity. This burner will run at
25% of its capacity until the system demand reaches
13%. At this point, the lit burner will be ramped up in
output, tracking with the total system demand. Once
the system demand reaches 30% (60% demand on
the one lit burner), the controller will fire the second
burner. Both burners will now be lit and running and
they will track the system demand together. In other
words, if the system demand is 48%, both burners
will be running at 48% of their rated capacities. Next,
as the system demand falls and reaches 25%, one of
the burners will shut off and the other burner will be
brought back up to 50% of its rated capacity. This
results in an overall system output of 25%. As the
demand continues to fall and reaches 13%, the one
operating burner will remain at 25% of its rated
capacity. When the total system demand falls
and reaches 5%, the one burner left running will be
shut off.
Operation
Control functions: adjusting set point.
Adjust set point through Set Up menu
Set point adjustments are accomplished through the
Set Up menu, which is under the Main Menu (refer to
the menu structure diagram on Page 27).
Once you have accessed the Set Up menu, you will be
able to adjust a number of parameters including the
set point of the unit. To adjust the humidity set point,
your unit must be configured for a humidity
transmitter. You may enter a desired humidity set
point anywhere in the range of 20% to 80%. Your set
point modifications will take effect as soon as you
press the Enter key or move to another parameter
using the Next or Back soft keys, or exit the set up
menu using the Main soft key.
Depending on your options, you may also be able to
adjust the high limit humidity set point and the dew
point set point. The high limit set point has a valid
range of 50% to 95%. The dew point set point has a
valid range of 20°F (-7°C) to 80°F (27°C). If your
unit is equipped with the dew point control option,
you will not have a desired humidity set point option.
Operation:
Adjusting set point
41
Operation
Control functions: PID tuning.
Tune your system with PID loop
The proportional term
When your unit is equipped with a humidity or dew
point transmitter (when you are able to adjust the set
point through the keypad/display) control is
accomplished through a PID control loop. PID stands
for Proportional, Integral and Derivative.
The proportional band is the band (in % RH, or °F/°C
for dew point control) in which the humidifier will
modulate.
With a PID loop, you are able to “tune” your system
for maximum performance using the proportional
(Kp), integral (Ki) and derivative (Kd) gain terms.
These gain factors work in the following way: The
overall demand in a PID system is made up of three
distinct parts that are added together. There is the
proportional piece, the integral piece and the
derivative piece. Each one of these parts is calculated
and then multiplied by a gain factor. These gain
factors are the setup variables that you have access
to. By making a gain factor larger, you increase its
component’s overall influence on the system demand
equation. Once the multiplication has taken place, all
three terms are added together to determine the
overall demand percentage. One other term that is
user-controlled in the PID equation is the
proportional band.
For example, if starting with a set point of 35% and a
proportional band of 10%, the humidifier operation
will be as follows: On initial start-up, assume an
actual humidity level of 15%. The proportional band
is 10% so the humidifier will modulate when the
actual humidity is in the range 25-45%. If the actual
humidity is lower than 25%, the humidifier will be
full on. If the actual humidity is above 45%, the
humidifier will be full off. In the example, starting at
an actual humidity level of 15%, the humidifier will
be full on. As the actual humidity level climbs into
the range of the proportional band (25-45%), the
humidifier will begin to modulate down. Once the set
point of 35% is reached, the humidifier will be full
off.
Looking at this scheme a little closer, a problem can
be found. In almost all applications there will be
some constant load on the humidifier just as there is a
constant load on the heating equipment. With this
control scheme, the actual humidity must be less than
the set point for the humidifier to be on. What ends
up happening is the humidifier finds a “happy
medium” where the actual humidity is something less
than the set point, which allows the humidifier to
continue to run. This difference between the set point
and the actual running humidity level is called the
“droop.” This droop can be corrected using the next
term, the integral gain.
The integral term
The integral gain affects how fast the humidifier will
react to a droop condition. The higher the number,
the faster the reaction. (An integral term of zero
disables this variable and allows the unit to run on the
proportional band only.) The way this term works is
as follows: When the actual humidity is in the
proportional band, the humidifier demand is
somewhere between 0 and 100 percent. Every 1/2
42
Operation:
PID tuning
Operation
Control functions: PID tuning (cont.).
second the demand is updated. With an integral gain
term greater than zero and an actual humidity below
set point, each time the demand is updated it is
increased slightly. If the actual humidity is above set
point, the demand will be decreased slightly. The
amount it is increased or decreased is dependent on
the difference between the actual humidity and set
point. (The closer you are to the set point, the smaller
the addition or subtraction.)
When looking at this control scheme, something
interesting is found. The total demand signal for the
humidifier is the sum of the proportional part, the
integral part and the derivative part. As the actual
humidity approaches the set point, the integral
portion makes up the majority of the demand and the
proportional part makes up very little. Once the set
point is achieved and the unit stabilizes, the entire
demand is made up of the integral part because the
proportional part is zero. If the actual humidity goes
over the set point, the integral term will start to
decrease. In addition, the proportional term will go
negative and actually start to subtract from the total
system demand. These two items work in conjunction
with each other to bring the humidifier back to set
point.
The derivative term
A derivative term’s basic function in a PID loop is to
anticipate where the demand is going and to help it
get there. Its basic operation is as follows: As the
humidifier is running, the PID loop is generating an
error term. (The error term is the mathematical
difference between the RH set point and the actual
measured RH.) If the actual measured RH is below
set point and is rising, the derivative term will
subtract from the demand in anticipation of the
approaching set point. If the actual measured RH is
below set point and is falling, the derivative term will
add to the demand in anticipation of the need to get
the demand up faster and start climbing toward set
point. The same is true for situations above the set
point. If the actual measured RH is above set point
and is rising, the derivative term will subtract from
the total demand in anticipation of needing to reduce
demand and get closer to set point. If the actual
measured RH is above set point and falling, the
derivative term will add to the overall demand in
anticipation of the approaching set point. In the
majority of control situations, the derivative term is
not needed and is simply set to zero. The
proportional term and integral term will provide very
tight, accurate control without the addition of the
derivative term.
PID setup tips
A large proportional band (10 to 20%) will yield
tighter and more stable control with longer response
times. A small proportional band will produce
quicker response times but control may become
unstable. As a rule of thumb, start with a band of
10%. If the unit does not “hunt” and a quicker
response is needed, the band can be lowered. If the
unit hunts or the fast response is not needed, increase
the band. This will result in more system stability.
(To increase or decrease the effect of the proportional
band on system performance, the proportional gain
factor may be adjusted. However, for the majority of
systems, the factory default setting of 80 is
sufficient.) A moderate integral gain term (30 to 50)
will also yield tighter and more stable control with a
longer response time. A large integral gain will
quicken the response but may cause the system to
become unstable. As a rule of thumb, start with an
integral term of 40. If the unit does not hunt and
quicker response is needed, raise the integral gain. If
the unit hunts or does not need the fast response,
decrease the integral gain.
Operation:
PID tuning
43
Operation
VAV, temp comp, dew point control.
VAV control
Dew point control
With VAV control, the system is equipped with a duct
high limit transmitter. This transmitter sends a signal
®
back to the VAPOR-LOGIC 3 controller. The controller
then compares the measured duct RH with the high
limit set point (Duct High Lim RH) that is entered
through the keypad/display in the Set Up screen. As
the measured duct RH approaches the high limit set
point, the system output is proportionally throttled
back. (This scaling of the output starts once the
measured RH is within 6% of the high limit set point.)
Once the measured duct RH drops, full system output
is automatically restored.
Dew point control functions in exactly the same way
as RH control except the dew point is being
measured instead of the RH. The dew point
transmitter sends a signal back to the
VAPOR-LOGIC3 controller. The user is able to
modify the dew point set point and PID parameters
through the keypad/display just as they could with an
RH transmitter.
Temperature compensation control
With temperature compensation (temp comp) control,
the system is equipped with a window temperature
transmitter. This transmitter sends a signal back to the
VAPOR-LOGIC3 controller. As the window glass
temperature decreases and approaches the dew point
of the room, the RH set point is automatically
decreased to prevent moisture or ice from forming on
the window. Once the window temperature rises, the
original RH set point is restored. This option is only
available when the system is equipped with an RH
transmitter. It is not available when a remote
humidistat or energy management system is used to
control the humidifier.
44
Operation:
VAV, temp comp, dew point control
Operation
Aquastat, heat-up, SDU, offsets, metric.
Aquastat operation
SDU timer
The aquastat set point is the minimum tank
®
temperature the VAPOR-LOGIC 3 controller should
maintain. It is adjusted through the Set Up screen.
This feature is typically used to keep the tank from
freezing in a cold environment. However, it can also
be used to hold a higher minimum temperature if a
quick response to a demand signal is needed. For
example, if the aquastat is set at 180°F (82°C), when
a call for humidity occurs, the tank will only need to
warm up 32°F (18°C) to reach the boiling point and
start producing steam. However, if the aquastat is at
its minimum setting of 40°F (4°C) and the tank is in
an average-temperature occupied room, the tank will
be sitting at about 70°F (21°C). Now, when a call for
humidity occurs, the tank will need to warm up
142°F (79°C) to reach the boiling point and begin
producing steam. This feature is standard on all
DRI-STEEM humidifiers with VAPOR-LOGIC 3
®
control except ULTRA-FOG and Steam Injection
humidifiers.
If your humidifier is equipped with a Space
Distribution Unit (SDU) or an Area-Type fan, you
have the option of controlling how long the fan will
run after a call for humidity has ended. This delay
(SDU Duration) is adjustable in one-minute intervals
through the Set Up screen.
Sensor offsets
All external transmitters shipped with
VAPOR-LOGIC3 can be field calibrated using the
keypad/display through the Set Up screen. For
example, if the system is equipped with an RH
transmitter, there will be an RH offset setting. The
factory default for all transmitter settings is zero.
However, if an adjustment is necessary, the keypad
can be used to adjust the transmitter reading up or
down through this setting. The sensors that have this
adjustment capability are the humidity, VAV high
limit, temp comp and dew point transmitters.
Tank heat-up feature
The tank heat-up feature uses the tank temperature
sensor to quickly heat a tank in response to a demand
signal. Its operation is as follows: If the tank is cold
(70°F) and a small demand signal is delivered, the
VAPOR-LOGIC3 controller will override the
demand signal and run the humidifier at 100%
demand until the tank temperature is 190°F (88°C). At
this point, control will be returned to the original
demand signal and the humidifier will begin normal
operation. This allows the system to respond quickly
to even the smallest demand. This feature is standard
on all DRI-STEEM humidifiers with
VAPOR-LOGIC3 control except ULTRA-FOG and
Steam Injection humidifiers.
Metric conversion
VAPOR-LOGIC3 is capable of displaying all
information in metric as well as standard units.
Operation:
Aquastat, heat-up, SDU, offsets, metric
45
Operation
Water level control: conductivity probe.
Probe system
Standard water systems use a conductivity probe to
control water levels for optimum operating
efficiency. The three-probe system is monitored by
the VAPOR-LOGIC®3 board, which performs all the
necessary logic and timing functions to provide total
water level control and safety shutdown.
VAPOR-LOGIC3 automatically maintains the water
level between the upper two probes A and B (see
Figures 46-1 and 46-2 below). When the water level
falls below probe B, the fill valve is opened until the
water level reaches the upper probe A. Water must
remain in contact with the probe surface for a
minimum of two seconds for VAPOR-LOGIC3 to
determine that the water is at the probe's level,
ensuring that turbulence does not cause an incorrect
level reading.
Figure 46-1: Conductivity probe system
®
®
®
®
for GTS , VLC , VAPORMIST and CRUV
Each time the fill valve is energized, the probe system
is tested by the VAPOR-LOGIC3 system. If the signal
from the probe assembly is beginning to deteriorate,
the message “Replace probes” will appear. Once the
probe system has reached its maximum usable life, the
humidifier will shut down and the message “Probe
fault” will appear.
An adjustable skim time allows for an extended skim
period (0-120 seconds) to reduce surface mineral
accumulation. When skimming, the fill valve remains
energized for the designated delay time after the
water level reaches the upper probe A.
Probe C provides low water protection for the
heating elements. If the water level falls below probe
C, the heaters are de-energized.
Figure 46-2: Conductivity probe system
®
®
for STS and LTS
Water level - A
Water level - B
Water level - A
Water level - C
Water level - B
OM-632
46
Operation:
Conductivity probe
Water level - C
OM-270
Operation
Water level control: float valve.
Float valve system
®
DI/RO water systems (except for ULTRA-FOG ) use
a float valve system to control water levels for
optimum operating efficiency. DI/RO systems are
used where water/steam purity is important, where
demineralized water is needed to improve
performance or lessen maintenance requirements, or
where a potable water source has minimal or no
conductivity, thus requiring a float rather than a
probe to sense water levels.
The float valve system consists of a fill float and a
low-water cutoff float.
The fill float regulates how much water is added
to the tank via a float, float arm and mechanical
valve. The valve is adjusted to within 1/4" of the
overflow (skimmer) port allowing heated and
therefore expanded water at start-up to fill the
external P-trap.
The low-water cutoff float has an electrical switch
that closes when a ready-water condition is
reached. A low voltage AC current runs from the
®
VAPOR-LOGIC 3 controller to the switch allowing
the controller to sense when the voltage drops as the
switch closes to ground at a ready-water condition.
Figure 47-1: Float valve system
used with DI/RO systems
Stripe mark indicates proper float ball placement on
stem. Switch is normally open when float ball is at its
lowest point on stem.
Stem
OM-3009
Operation:
Float valve
47
Operation
Drain and flush, skim.
Drain and flush options
®
VAPOR-LOGIC 3 is preprogrammed to enter an
automatic drain, flush and refill cycle to help keep
mineral concentrations in the tank to a minimum. The
method by which this is accomplished is selected by
the user through the keypad/display in the Set Up
screen. The three options available are:
1. Flush after usage
2. Flush at a certain time after usage, and
3. Flush at a certain time
Please note that these options are only available with
a standard water system having an automatic drain
valve. If the humidifier is configured for DI/RO
water, or if the unit has a manual drain valve, these
drain and flush options are not available.
In the flush after usage mode, the humidifier will
enter the drain and flush sequence after a userselected amount of water has been converted to
steam. In other words, if the user set the drain and
flush interval to 10,000 pounds, the unit will enter the
drain and flush sequence the moment 10,000 pounds
of water have been boiled.
In the flush at a certain time after usage mode, the
humidifier will enter the drain and flush sequence at
a specific time after a user-selected amount of water
has been converted to steam. In other words, if the
user sets the drain and flush interval to 10,000
pounds and the ADS Hour to 2, the unit will enter the
drain and flush sequence at 2:00 am after 10,000
pounds of water have been boiled. This allows the
user to keep the humidifier on line until a convenient
time for the drain and flush sequence.
48
Operation:
Drain and flush, skim
In the flush at a certain time mode, the humidifier will
enter the drain and flush sequence at a specific time,
ignoring the amount of water that has been converted
to steam. In other words, if the user sets the ADS
Hour to 2, and the ADS Interval to 7 days, the unit will
enter the drain and flush sequence every 7 days at
2:00 am.
When VAPOR-LOGIC3 initiates the drain and flush
sequence, all activated heat sources are deactivated.
The drain valve is then opened to allow the tank to
drain. The drain valve remains open during the flush
sequence for drainage while the fill valve is open. At
the completion of the flush cycle, the drain valve
closes allowing the fill valve to refill the tank. For
multiple tank systems, only one tank at a time enters
the drain and flush sequence in order to keep as much
capacity available as possible.
Skim timer
With a standard water configuration, the
VAPOR-LOGIC3 controller comes equipped with a
skim timer. This timer is activated at the end of each
fill cycle. The timer keeps the fill valve open for a
user-determined amount of time after the tank has
filled to skim minerals off the water surface. The
skim time is adjusted through the Set Up screen on
the keypad/display.
Operation
Service interval, EOS, date set.
Setting date and time
Service interval
®
The VAPOR-LOGIC 3 controller keeps track of how
much water has been converted to steam. After a
user-defined number of pounds/kilograms have been
boiled, a service humidifier message will appear on
the keypad/display. However, the humidifier will
continue to operate after the message appears. The
message is simply to notify the user that the service
interval has been reached. This service interval is
adjustable through the Set Up screen on the keypad/
display.
The VAPOR-LOGIC3 controller contains a real-time
clock that is used for several features including the
drain and flush sequence and the logging of alarms.
If it becomes necessary to reset the date or time, they
are accessible through the Set Up screen on the
keypad/display.
End of season drain
If there is no call for humidity for a preset time
period, the humidifier will be placed in End of
Season (EOS). When the unit enters End Of Season,
the humidifier is placed in Standby Mode. The drain
valve is held open for one hour to allow the tank to
drain and then it is closed. If the humidifier receives
a call for humidity after the end-of-season drain, it
automatically leaves the Standby Mode and returns to
the Auto Mode. The tank is refilled and the
humidifier resumes normal operation. The amount of
inactivity time that is needed before the humidifier
enters End Of Season is adjustable through the Set
Up screen on the keypad/display (Inactivity Until
EOS). This option is only available on units that are
equipped with automatic drain and fill valves.
Operation:
Service interval, EOS, date set
49
Operation
Safety features.
Over-temp fault
Fill timer
®
The VAPOR-LOGIC 3 controller keeps track of
approximately how much water, in the form of steam,
has left the tank. If this total amount exceeds a preset
limit without the fill valve being energized, a low water
condition is assumed and the humidifier is shut down.
Each time the fill valve is energized, the total is reset
to zero. Note that this system is not used on a DI/RO
humidifier because the fill valve is not an electricsolenoid type. On a DI/RO tank, a mechanical fill
valve maintains the proper water level. This fill valve
operates independently of the VAPOR-LOGIC3
controller. Therefore, on a DI/RO system, there is no
way to reset the steam total to zero as the tank fills.
50
Operation:
Fill timer, over-temp fault
The tank temperature is constantly monitored by the
VAPOR-LOGIC3 controller. If the temperature ever
rises above a preset limit, the humidifier is shut down
and a thermal trip fault is given on the Alarms screen
of the keypad/display. This fault must be cleared or
acknowledged on the Alarms screen by the user
before humidifier operation will resume.
Operation
Fault messages, diagnostics.
Alarms screen
Fill and drain faults
The Alarms screen on the keypad/display logs the
last ten alarms that have occurred on the humidifier.
To scroll through the alarms, use the up and down
arrow keys. You can acknowledge or clear any one
of the alarms using the appropriate soft keys. If an
alarm has occurred that you would like to get more
information about, highlight that alarm using the
arrow keys and then press the Enter key. A screen
will appear that gives you the time and date the alarm
occurred as well as a more detailed explanation of
what the alarm means.
The following is a list of fill and drain faults that can
occur. Please note that this is a complete list of faults.
Your system may not have all of these options. The
text in parentheses is what will actually appear in the
alarm log.
•
Fill fault (Fill Fault)
The fill valve has been energized for more than
40 minutes without the water reaching the top
probe.
•
Drain fault (Drain Fault)
The drain valve has been energized for more
than 20 minutes without the water falling off the
bottom probe.
•
Low water timer fault (Fill Time Flt)
The unit has run too long without the fill valve
opening.
•
LL probe fault (LL Probe Fault)
The water in the tank has reached the middle or
upper probe without reaching the lower probe.
•
ML probe fault (ML Probe Fault)
The water in the tank has reached the upper
probe without reaching the middle probe.
•
Probe assembly fault (Probe Assy Flt)
The system has detected the deterioration of the
probe assembly to a point that replacement is
necessary.
Sensor faults
The following is a list of sensor faults that can occur.
Please note that this is a complete list of faults. Your
system may not have all of these options. The text in
parentheses is what will actually appear in the alarm
log.
•
Humidity transmitter fault (RH Trans Fault)
The humidity sensor is incorrectly wired or bad.
•
Dew point transmitter fault (DP Trans Fault)
The dew point sensor is incorrectly wired or
bad.
•
VAV humidity transmitter fault
(VAV Tran Fault)
The duct humidity sensor is incorrectly wired or
bad.
•
Temp comp transmitter fault
(Temp Trans Flt)
The temperature compensation sensor is
incorrectly wired or bad.
Operation:
Fault messages, diagnostics
51
Operation
Fault messages, diagnostics (cont.).
52
Humidifier faults
Sensor meter feature
The following is a list of humidifier faults that can
occur. Please note that this is a complete list of faults.
Your system may not have all of these options. The
text in parentheses is what will actually appear in the
alarm log.
The Diagnostics screen on the keypad/display
contains the sensor meter feature. This feature allows
the user to read the state of all of the current inputs to
®
the VAPOR-LOGIC 3 controller.
•
Temperature sensor fault (Tank Temp Flt)
The temperature sensor on the humidifier tank is
incorrectly wired or bad.
•
Thermal trip fault (Thermal Trip)
The tank temperature has exceeded 245°F
(118°C).
•
SDU fault (SDU Fault)
The SDU blower pressure switch failed to close
when the SDU was started.
•
EEPROM fault (EEPROM Fault)
The controller has detected a check sum fault in
the EEPROM memory.
•
Flue fault (Flue Fault)
The air damper limit and/or the power vent
pressure switch failed to close.
•
Burner # fault (Burner # Fault)
The burner failed to light after three ignition
attempts.
•
Ignitor # fault (Ignitor # Fault)
The ignition module failed to energize the gas
valve.
•
Blower # fault (Blower # Fault)
The blower was unable to reach the desired
speed.
•
GTS only: Slave # fault (Slave # Fault)
One of the humidifiers in a multiple tank system
is not responding to communication requests.
•
Boil time fault (Boil Time Flt)
The water in the tank failed to boil within the
maximum boil time.
®
Operation:
Fault messages, diagnostics
To scroll through the screens, use the Next and Back
soft keys to select the input you wish to check. When
you are done, press the Main soft key to return to the
Main Menu screen.
Operation
Reports, multiple tank systems.
Energy usage report
Multiple tank systems
The energy usage report gives an approximate total of
how much energy has been consumed by the
humidifier since the last service interval. Depending
on the system type, this number may be in KWH,
MBTU, therms, etc.
The VAPOR-LOGIC 3 controller has the ability to be
®
connected via a LonTalk network to control up to six
tank humidification systems. These multiple tank
systems operate in exactly the same way as single
tank systems. The multiple tanks work together to
generate the desired level of humidity. The
humidifiers are brought on line sequentially, which
means that one humidifier must be running at full
capacity before the next one is brought on line.
However, the VAPOR-LOGIC3 controller monitors
the demand signal and will begin to preheat
additional tanks as the demand signal rises so that
there is a seamless transition in output when
additional tanks are brought on line.
Water usage report
The water usage report gives an approximate total of
how many pounds/kilograms of water have been
converted to steam since the last service interval.
®
Operation:
Reports, multiple tank systems
53
Operation
Troubleshooting 1, 2, 3.
1.
3.
Review troubleshooting index
Call us if you’re still having problems
If you find that you are having a control-related
problem, first check the problem list on the next
page. If you are having a tank- or dispersion-related
problem, you may also need to refer to those specific
product manuals.
If the troubleshooting guide does not help you solve
your problem, call us with the following information
available:
2.
Review possible causes and
recommended actions
The troubleshooting section presents possible causes
and recommended actions for typical problems.
1. Product name, program code, and order
number
You’ll find this information on the wiring
diagram and on the outside of the control cabinet
door.
2. Problem definition
(Water leaking, low humidity, high humidity,
etc.)
3. Time problem began
(Always, after remodel, after a change in
weather)
4. System changes
(Pressure, new boiler, new service, new
controller, relocation, change in maintenance)
Humidifier model number ___________________
Humidifier serial number ___________________
VAPOR-LOGIC3 program code ________________
54
Operation:
Troubleshooting introduction
Operation
Index to troubleshooting guide.
The following is an index to possible control-related problems described on the following pages. To find
solutions, refer to either the problem number or the page number shown.
#
Description
1.
2.
3.
Green power indicator light is off .................. Page 56
No remote fault indication ............................. Page 56
No readable information on keypad/display .. Page 56
Faults
4. Humidity transmitter fault .............................. Page 56
5. Dew point transmitter fault ............................ Page 56
6. Humidistat fault .............................................. Page 57
7. VAV humidity transmitter fault ..................... Page 57
8. Temp comp transmitter fault .......................... Page 57
9. Fill fault .......................................................... Page 57
10. Drain fault ...................................................... Page 58
11. Low water timer fault ..................................... Page 58
12. LL probe fault ................................................ Page 58
13. ML probe fault ............................................... Page 59
14. Replace probes fault ....................................... Page 59
15. Probe assembly fault ...................................... Page 59
16. Temperature sensor fault ................................ Page 59
17. Thermal trip fault ........................................... Page 59
18. SDU fault ........................................................ Page 59
19. EEPROM fault ............................................... Page 59
20. Flue fault ........................................................ Page 60
21. Burner # fault ................................................. Page 60
22. Ignitor # fault .................................................. Page 60
23. Blower # fault ................................................. Page 60
24. Slave # fault .................................................... Page 61
Operation problems
25. Control does not energize ............................... Page 61
26. Unit does not fill with water ...................... Page 61-62
27. Fill valve does not close ............................ Page 63-64
28. Reduced or no output ..................................... Page 64
29. Fill valve cycles on and off frequently ........... Page 65
30. Heater burnout ................................................ Page 65
31. Noisy operation .............................................. Page 66
32. Humidity below desired level ...................Page 67-68
33. Humidity above set point ..........................Page 68-69
34. Hunting ........................................................... Page 69
35. Will not perform autodrain ............................. Page 70
Operation:
Index to troubleshooting guide
55
Operation
Troubleshooting guide.
Problem
number
1
2
Problem
Possible cause
Action
Green power indicator
light is off.
• No control voltage
present
• Check for proper supply voltage.
• Heater fuses open
• Check heater fuses for voltage present
at transformer.
• Transformer
secondary circuit
breaker tripped
• Check for wiring shorts; reset breaker.
• Field wiring not
installed
• Provide field wiring to a remote fault
indicator from VAPOR-LOGIC®3
terminal block J22.
No remote fault
indication
• Field-supplied remote • Check if lamp by others is burned out;
replace if needed.
fault indicator lamp is
burned out.
• Check relay continuity
• Remote fault
(VAPOR-LOGIC3 terminal J22) for
VAPOR-LOGIC3
relay is not switching.
contact closure.
3
No readable
information on
keypad/display
• No power, or
incorrect voltage to
VAPOR-LOGIC3
board
• Check main power supply.
• Modular
communication cable
is disconnected.
• Connect modular cable.
4
Humidity transmitter
fault
• Open, shorted, or
incorrect wiring of
transmitter
• Check wiring terminals
(VAPOR-LOGIC3 terminal J26) for
correct wiring and voltages.
5
Dew point transmitter
fault
• Open, shorted, or
incorrect wiring of
transmitter.
• Check wiring terminals
(VAPOR-LOGIC3 terminal J26) for
correct wiring and voltages.
More on next page ...
56
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
6
Problem
Possible cause
Action
Humidistat fault
• Open, shorted, or
incorrect wiring of
humidistat
• Check wiring terminals
(VAPOR-LOGIC®3 terminal J26) for
correct wiring and voltages.
• Signal by others is
incorrect, out of
range, or miswired.
• Check wiring terminals
(VAPOR-LOGIC3 terminal J26) for
correct wiring and voltages.
• Control signal by
others has exceeded
the range limits.
• Correct control signal to 0-20 mA,
0-135 ohms, or 0-15 VDC.
7
VAV humidity
transmitter fault
• Open, shorted, or
incorrect wiring of
transmitter
• Check wiring terminals
(VAPOR-LOGIC3 terminal J27) for
correct wiring and voltages.
8
Temp comp
transmitter fault
• Open, shorted, or
incorrect wiring of
transmitter
• Check wiring terminals
(VAPOR-LOGIC3 terminal J28) for
correct wiring and voltages.
• Sensor improperly
located
• Transmitter must be on inside window
glass only.
• When in the fill
sequence,
VAPOR-LOGIC3
allows 40 minutes
for the water to reach
the maximum proper
level.
• Check water supply shut-off valve. If it
is closed, open the valve.
• If the water does not
reach the designated
level, and the probe
system is not
satisfied, a fault will
be indicated.
• Check if the in-line strainer or valves
are plugged. Clean them as needed.
• Check if there is 24 VAC present at
control board terminals 1 and 2. If yes,
replace valve.
• Verify proper fill valve wiring.
• Clean or replace probe.
• Verify drain valve is closed.
• Verify proper water pressure,
minimum 25 psi.
9
Fill fault
More on next page ...
Operation:
Troubleshooting guide
57
Operation
Troubleshooting guide.
Problem
number
Problem
Possible cause
Action
10
Drain fault
• When in autodrain
sequence, end-ofseason, or manual
drain,
VAPOR-LOGIC®3
allows 20 minutes
for the water level to
drop from the top
probe to below the
lowest probe. If the
tank does not drain
to this level in the
time allotted, a fault
will be indicated.
• Check drain valve wiring.
• Check for voltage present at the valve.
If present, clean or replace valve.
• Check if the tank drain outlet is
plugged. Clean outlet if needed.
11
Low water timer fault
• Fill valve is stuck
open.
• Check valve for foreign matter.
• Fill valve is installed
backwards.
• Check arrow direction on strainer. “In”
should be visible on fill valve body.
• Water probes have
not proven.
• Drain valve may be stuck open. Clean
or replace valve.
• Water is not conductive for probe
system. Add salt or convert to DI
control.
• Improper water level
changes inside the
tank
• Verify proper wiring of probe system.
• Clean or replace probe rod assembly.
• Rewire probes using nonshielded 18gauge wire routed in conduit separate
from power wiring.
• Check that wiring between control
cabinet and humidifier does not exceed
the recommended 50-foot limit.
• Check for plumbing problems.
12
LL probe fault
More on next page ...
58
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
Problem
Possible cause
Action
13
ML probe fault
• Improper water level
changes inside the
tank
• Verify proper wiring of probe system.
• Clean or replace probe rod assembly.
• Rewire probes using nonshielded 18gauge wire routed in conduit separate
from power wiring.
• Check that wiring between control
cabinet and humidifier does not exceed
the recommended 50-foot limit.
• Check for plumbing problems.
14
Replace probes fault
• Dirty probes
• Clean probes.
15
Probe assembly fault
• Deterioration of probe • Replace probe rod assembly.
rod assembly
16
Temperature sensor
fault
• Open, shorted, or
incorrect wiring of
sensor
• Check wiring terminals
(VAPOR-LOGIC®3 terminal J25) for
correct wiring and voltages.
17
Thermal trip fault
• Unit has overheated.
• Check for proper water level in tank.
18
SDU fault
• SDU blower or AFPS
is incorrectly wired.
• Check SDU for proper wiring.
• SDU blower motor is
defective (SDU fan
does not start).
• Replace SDU blower.
• Internal program
changed
(VAPOR-LOGIC3
detected a change
from its previous
program check)
• Consult DRI-STEEM for
reprogramming instructions.
19
EEPROM fault
More on next page ...
Operation:
Troubleshooting guide
59
Operation
Troubleshooting guide.
Problem
number
Problem
Possible cause
Action
20
Flue fault
• The combustion air
damper is incorrectly
wired or has failed to
open.
• Check for proper combustion air
damper wiring.
• The power vent
pressure switch is
incorrectly wired or
the power vent has
failed to start.
• Check for proper power vent wiring.
21
22
23
Burner # fault
Ignitor # fault
Blower # fault
• No gas supply to unit
Verify that gas service valve is on and
receiving minimum pressure to
manifold per rating plate.
• Gas valve is off or
there is no power to
the valve.
• Verify that valve is in “on” position and
that there is power to the valve.
• Broken ignitor
• Verify that ignitor glows.
• Gas valve/ignitor/
sensing electrode is
out of sequence
• Verify wire connections to these
components.
• Gas valve outlet
pressure is too low.
• Verify out pressure is set per rating
plate.
• Blower inlet is dirty
or obstructed.
• Clean inlet and check for obstructions.
• Broken ignitor
• Verify that ignitor glows.
• Gas valve/ignitor/
sensing electrode is
out of sequence.
• Verify wire connections to these
components.
• The blower is
incorrectly wired or
the blower failed to
start.
• Check for proper blower wiring.
More on next page ...
60
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
24
25
26
Problem
Possible cause
Slave # fault
• LonTalk®
• Connect LonTalk communications
communications cable
cable.
is not connected
between boards.
Control does not
energize.
Unit does not fill with
water.
Action
• Slave board does not
have power or has
incorrect power.
• Verify power wiring on slave board.
• Nonexistent supply
voltage to unit
• Check main line fuse.
• Check main line safety switch.
• Check heater fuses.
• Nonexistent control
voltage
• Check for proper supply.
• Verify proper transformer voltage
characteristics.
• Verify proper wiring of transformer.
• Check for control circuit voltage, 24
VAC. If voltage is not present, check
transformer circuit breaker. Reset if
needed.
• Heater overtemperature
thermostat open
• Reset manual switch located above
heater or humidifier cover.
• Malfunctioning fill
valve
• First, disconnect brown wire and then
®
the orange wire from VAPOR-LOGIC 3
board terminals 30 and 31 of terminal
block J8. Fill valve should open.
• If fill valve does not open, verify
proper 24 VAC (terminals 1 and 2) to
fill valve. If voltage is present and
valve does not open, replace valve or
valve coil.
• Verify that coil is 24 VAC.
• Verify that valve stem moves freely.
• No water supply to fill • Check if water supply line strainer is
valve
plugged.
• Verify that manual water line shut-off
valve is open and that pressure exists.
More on next page ...
Operation:
Troubleshooting guide
61
Operation
Troubleshooting guide.
Problem
number
26
Problem
Possible cause
Action
Unit does not fill with
water (cont.).
• Unit is not in auto
mode.
• Go to Control Modes screen and select
Auto Mode.
®
• VAPOR-LOGIC 3
control is in “end of
season” drain mode.
• Check for humidity demand
(VAPOR-LOGIC3 control board
terminals 21, 22 and 23 of terminal
block J26).
• Malfunctioning level
control system
• Disconnect brown and orange wires
connected to VAPOR-LOGIC3 board
terminals 30 and 31 of terminal block
J8. If fill valve does not open, check
for proper 24 VAC (terminals 1 and 2)
to fill valve coil. If proper voltage is
not present, the control board is
defective.
• Check terminals 30, 31, 32 and 33 on
VAPOR-LOGIC3 control board
terminal block J8 for correct voltage:
– 32 (purple) to 33 (yellow),
no water present > 2 VAC
– 32 (purple) to 33 (yellow),
water present < 1/4 VAC
– 31 (orange) to 33 (yellow),
same readings as above
– 30 (brown) to 33 (yellow),
same readings as above
• Inlet water needle
valve is closed.
• Check needle valve.
More on next page ...
62
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
27
Problem
Fill valve does not
close.
Possible cause
Action
• Open drain valve
• If automatic drain valve is locked in
manual open position, reset to
automatic.
• Replace valve if there is a broken
return spring on the drain valve.
• Clean or replace drain valve if an
obstruction in the valve will not allow
complete closure.
• Close manual drain valve, if it is open.
®
• If VAPOR-LOGIC 3 shorted output to
fill valve coil, replace board.
• Malfunctioning level
control system
• Check if probe head is fully plugged
in.
• If needed, clean probe rod tips.
• Verify if VAPOR-LOGIC3 control
board with nylon mounting standoffs
terminal 33 needs to be grounded.
• If there is low water conductivity, add
salt to tank water. (If this solves the
problem, consult DRI-STEEM for
further advice.)
• Replace board if VAPOR-LOGIC3
control board is defective.
• Verify that system is in auto mode.
• Verify that probe is wired correctly.
• Check terminals 30, 31, 32 and 33 on
VAPOR-LOGIC3 control board
terminal block J8 for correct voltage:
– 32 (purple) to 33 (yellow),
no water present > 2 VAC
– 32 (purple) to 33 (yellow),
water present < 1/4 VAC
– 31 (orange) to 33 (yellow),
same readings as above
– 30 (brown) to 33 (yellow),
same readings as above
More on next page ...
Operation:
Troubleshooting guide
63
Operation
Troubleshooting guide.
Problem
number
Problem
Possible cause
Action
27
Fill valve does not
close (cont.).
• Fill valve is stuck
• Check if fill valve is installed
backwards. If yes, repipe.
• If there is a faulty internal spring or
diaphragm in the fill valve, replace
valve.
• Check if there is an obstruction that
will not allow valve to seat properly.
Clean or replace valve as needed.
• Check for control voltage across fill
valve coil. (Check wiring and
controls.)
28
Reduced or no output
(even though water
level is correct)
• Heater
malfunctioning
• Verify that proper voltage is being
applied to heaters.
• Check heater amperage.
• If heater contactor is not functioning,
replace.
• Malfunctioning
control system
• Check if heater fuses are blown and
replace if required.
• Check if auxiliary limit controls are
not allowing system to operate (i.e.,
duct humidistats, air flow proving
switch, etc.). Reset, replace or
calibrate as needed. (Air flow switch,
terminals 12 and 13, measures 24
VAC if open. On-off high limit,
terminals 25 and 26, measures 21
VDC if open.)
• Check if the (optional) heater overtemperature thermostat has been
tripped. Reset if necessary.
• Replace zone valve if end switch is
not closing.
More on next page ...
64
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
29
30
Problem
Possible cause
Action
Fill valve cycles on and • Malfunctioning level
off frequently (several
control system
times per minute).
• If needed, clean probe tips.
• Check water conductivity. (Minimum
conductivity for proper operation of
level control system is 100 micromhos
per centimeter or 2 grains per gallon.)
• Verify that probe wiring is correct.
• Drain valve not fully
closed
• If an obstruction will not allow drain
valve to fully close, clean valve.
• If there is a broken or weak return
spring on drain valve, replace the
valve.
• Check if 24 VAC is present at valve. If
®
so, check wiring of VAPOR-LOGIC 3
control board terminals 3 and 4.
Heater burnout
• Water level is too low. • Check probes and clean tips if
necessary.
• Clean probe still-well area in tank.
• Check drain valve and clean, repair, or
replace as needed.
• Improper wiring
• Verify proper voltage applied to heater.
• Verify proper electrical connections.
• Mineral buildup
• Inspect tank for severe mineral buildup
impeding heat transfer
on or around heater. Increase
to water
skimming quantity, frequency of drain
cycle, and/or frequency of cleaning.
Use softened makeup water.
• Heater corrosion
• Inspect heater for surface corrosion or
pitting. If evident, consult
DRI-STEEM.
More on next page ...
Operation:
Troubleshooting guide
65
Operation
Troubleshooting guide.
Problem
number
31
Problem
Noisy operation
Possible cause
Action
• “Thunder”-type
noise coming from
tank during refill
• Normal on larger units, caused by the
cold fill water collapsing steam in the
tank. Reduce psi (minimum of 25 psi)
if inlet water pressure is too high.
• Contactor noise
• Contactor normally makes a “clunk”
as it pulls in. A continuous chattering
noise is not normal and is
symptomatic of a failing contactor or
malfunctioning controls. Replace
contactor or troubleshoot the control
system.
• Fill valve noise
• A clicking sound as fill valve opens
or closes and a hissing sound during
fill are normal. A slamming sound as
fill valve closes is “water hammer”
and can be minimized by installing a
shock arrester.
• A loud buzzing sound indicates poor
alignment of valve stem. Replace
valve.
More on next page ...
66
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
32
Problem
Possible cause
Action
Humidity below
desired level
• Unit operating but
fails to meet required
humidity output
• Unit undersized; replace with a larger
unit or add additional humidifier.
• Skimmer rate is too high.
• If drain valve will not close fully,
determine the cause and clean, repair
or replace as needed.
• If drain pipe water seal is allowing
steam to go down the drain, repair as
needed.
• If there is an improper water seal
height, increase to recommended
height. (See humidifier tank manual.)
• If there is excessive internal steam
pressure, determine the cause of the
high pressure (e.g., high duct static
pressure, undersized orifices in
dispersion tubes, water, or crushed
vapor hose) and repair as required.
• Replace leaking gasket or vapor hose.
• Recalibrate if controls are out of
calibration.
• If fill valve is stuck open, repair or
replace.
• If zone valve will not open, repair or
replace.
• No call for humidity
from humidistat or
from control and high
limit humidity
transmitters
• Low or no signal strength from
humidistat. Check for proper wiring.
• Check humidity transmitters (4-20 mA
output).
• Adjust set point if VAPOR-LOGIC®3
set point is too low.
• Excessive outside air
volume
• Verify proper operation of fans,
dampers, VAV systems, etc.
More on next page ...
Operation:
Troubleshooting guide
67
Operation
Troubleshooting guide.
Problem
number
32
33
Problem
Possible cause
Action
Humidity below
desired level
(cont.)
• Heating elements
not operating
• If heaters are burned out, refer to
Problem #30 “Heater burnout.”
• Verify that humidistat is calling for
humidity.
• Check for control voltage if limit
controls (air flow proving switch, zone
valves, etc.) are not allowing unit to
operate.
• Check fuses and replace if they are
blown.
• Check if the (optional) heater overtemperature has been tripped. Reset if
necessary.
• Humidity control
input type not the
same as
VAPOR-LOGIC3
software
• Check VAPOR-LOGIC®3 control board
connections J26, J27 and J28. Consult
DRI-STEEM.
• High entering
relative humidity
• Dehumidify.
• Unit oversized
• Consult DRI-STEEM.
• Reduced air flow
• Check fans, dampers, VAV systems,
etc.
• Improperly located
humidistat or
humidity
transmitters
• Relocate using guidelines established
in this manual (see Pages 16-23).
Humidity above set
point
More on next page ...
68
Operation:
Troubleshooting guide
Operation
Troubleshooting guide.
Problem
number
Problem
Possible cause
Action
33
Humidity above set
point (cont.)
• Malfunctioning
controls
•
•
•
•
34
Hunting
(humidity swings
above and below
desired set point)
• Malfunctioning
control system
• If there is a faulty or inaccurate
humidity controller or transmitter,
repair or replace.
• Check for proper VAPOR-LOGIC®3
control settings: RH set point, HL set
point, cycle rate, PID tuning, etc.
• Relocate poorly located control
components. See humidity control
placement information on Pages 16-23
for recommendations.
• If inappropriate control components are
being used, change components.
• On SSR units: Control wire and power
wires must be physically separated
from each other. If they are not, an
induced control voltage may occur,
causing erratic operation.
• Verify that 6-wire modular cable is
isolated from power wiring.
• Air volume is varying
rapidly.
• Stabilize.
• Air temperature is
varying rapidly.
• Stabilize to ±1°F.
Check for incorrect supply voltage.
Check for incorrect control signal.
Check for improper wiring hookup.
If humidity controller or transmitter are
out of calibration or malfunctioning,
repair or recalibrate.
• If zone valve end switch is not opening,
repair or replace.
• Check if SSR shorted. Repair or
replace as needed.
More on next page ...
Operation:
Troubleshooting guide
69
Operation
Troubleshooting guide.
Problem
number
35
Problem
Possible cause
Action
Unit does not perform
autodrain sequence.
• System may not have
automatic drain
system
• Inspect unit to verify that automatic
drain valve was furnished.
• Drain fault, plugged
• Clean drain valve piping.
drain valve or plugged
drain pipe
70
Operation:
Troubleshooting guide
• Malfunctioning
autodrain sequence
• Check VAPOR-LOGIC®3 main menu
settings and reset if necessary.
• No power to
automatic drain valve
• Check if 24 VAC is present at
VAPOR-LOGIC3 control board
terminals 3 and 4 and drain valve.
• Defective automatic
drain valve
• Valve should be replaced if voltage is
present at valve and it still does not
open.
71
72
14949 Technology Drive • Eden Prairie, MN 55344
Phone: (612) 949-2415 • Fax: (612) 949-2933
E-Mail: sales@dristeem.com • Web: www.dristeem.com
European Office:
Bell Place, Bell Lane • Syresham, Brackley • NN13 5HP, U.K.
Phone: +44 1280 850122 • Fax: +44 1280 850124
E-Mail: 106277.1443@compuserve.com
Printed
on recycled paper.
Printed on recycled paper with agribased inks
Minimum 10% Post Consumer Waste.
Continuous product improvement is a policy of The DRI-STEEM Humidifier Company therefore,
product features and specifications are subject to change without notice.
VAPOR-LOGIC, GTS, STS, LTS, CRUV, VAPORSTREAM, VAPORMIST, ULTRA-FOG and ULTRA-SORB
are registered trademarks of The DRI-STEEM Humidifier Company.
Form No. VL3OM-0799
Copyright © 1999 DRI-STEEM Humidifier Company, Inc.
Printed in U.S.A.
73