Armstrong EUH-601 Owners Manual

Armstrong EUH-601 Owners Manual
READ AND SAVE THESE INSTRUCTIONS
Bulletin No. 526-G
HUMIDIFICATION
Installation and Maintenance of
Armstrong EHU-600 Series Humidifiers
The Armstrong EHU-600 Series humidifier is an electronically controlled,
non-pressurized, electric steam-generating humidifier, with its vapor discharged into a
duct of an air-handling system or through a fan package.
To allow the EHU-600 Series humidifier to function to its full capability, be certain to
install in accordance with Armstrong recommendations.
These installation and maintenance guidelines should be used by experienced personnel as a guide to ensure that the Armstrong EHU Humidifier functions correctly. Selection
or installation of equipment should always be accompanied by competent technical
assistance. We encourage you to contact your local representative or Armstrong if further
information is required.
Installation and Maintenance
EHU-600 Series Humidifiers
READ AND SAVE THESE INSTRUCTIONS
Table of
Contents
A. Pre-Installation • • • • • • • • • • • • • • • • • • • • • • • • Page 3
1. Check shipment
2. Check local codes
3. Site selection
B. Installation • • • • • • • • • • • • • • • • • • • • • • • • • Page 4
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Mounting the humidifier
Electrical wiring
Water fill supply
Drain connection
Steam generator
Steam dispersion tube
Control humidistat
High limit duct humidistat
Fan interlock switch
Wiring diagrams
Capacity chart
Physical data
Submittal drawings
C. Principle of Operation • • • • • • • • • • • • • • • • • • Page 15
1. Operation
2. Suggested Specification
3. Display (instrument) panel
D. Start-Up Procedure • • • • • • • • • • • • • • • • • • • • Page 19
E. Maintenance • • • • • • • • • • • • • • • • • • • • • • • • • Page 22
1.
2.
3.
4.
5.
Recommended maintenance schedule
Water quality
Steam generator cleaning
Electrode installation
Parts list
F. Diagnostics • • • • • • • • • • • • • • • • • • • • • • • • • • Page 29
1. Output circuits
2. Input circuits
G. Humidistat Troubleshooting • • • • • • • • • • • • • • Page 31
© Armstrong International, Inc. 2003
2
Installation and Maintenance
EHU-600 Series Humidifiers
Pre-Installation
1. Check Shipment
A claim should be filed with the transportation company (and reported
to Armstrong) if any items are missing or damaged. Your shipment
may consist of as many as four cartons which contain:
a. Humidifier
b. Steam generator(s) (two cartons on Model EHU-602)
c. Steam dispersion tube, Fan Package or HumidiPack
Dispersion Panel.
All controls (control humidistat, high limit stat, etc.) if ordered, are shipped
in a marked package inside the humidifier.
2. Check Local Codes
EHU-600 Series humidifiers should be installed in accordance with
all applicable building, plumbing, and electrical codes.
3. Site Selection (See Fig. 3-1)
Electronic steam humidifiers should be installed in locations that
allow routine inspection and accessibility for maintenance operations. Armstrong recommends that electronic steam humidifiers
not be placed in false ceilings or in locations where unusual
instances of malfunction of the humidifier or the system might cause
damage to non-repairable, unreplaceable, or priceless property.
Note: Please contact factory for duct applications offering high static pressure (>4" WC).
Steam Piping, 1”/12”
Pitch Piping Back
Close to Main
Power Disconnect
Duct
Dispersion Tube
Separate Cabinet Drain
with Water Seal EHU-600 & 602 Only
Pitch Drain Piping 1”/12”
on Horizontal Runs
Valved
Water Supply
Figure 3-1: Site Selection - General Installation Concept
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Installation and Maintenance
EHU-600 Series Humidifiers
The mounting surface should be a wall of ordinary
studded construction or other construction of equivalent
strength, capable of supporting the maximum
humidifier weight. Maximum operating weights are:
Steam Hose Outlet
Wall
4" Clearance
4" Clearance
18" Min. Steam
Generator Tank
Removal
Model No.
EHU-600
EHU-601
EHU-602
EHF-2
EHF-3
5"
5" Min.
MIN. Drain
DRAIN
Pan
PAN
Piping
PIPING
and
Removal
AND
REMOVAL
Figure 4-1: Model EHU-600 Access Space
The location should be close enough to the air duct so
that the length of steam hose or pipe is as short as
feasible. A length of 10 ft. or less is ideal; the maximum
recommended length for running copper tube is 40 feet.
See Page 6, Item 6 of the Installation Section for more
details on steam dispersion tube location.
24"
24"
Maximum Operating Weight
lb.
Kg
80
36
104
47
145
66
32
14.6
33
15
See Figures 4-1 and 4-2 for access space.
5"
Figure 4-2: Access Space for
EHU-601 and EHU-602
Installation
Right
Side
18" Min.
Clearance
5" Min.
Clearance
Mounting Bracket
3/8” x 1-1/2” Lag Screws
on 18-1/4” Centers
Wall
WALL
See Page 14 for
Drain Connections
Figure 4-3: Mounting Clearances
The location chosen should be inside with a minimum ambient
temperature of 40°F. and a maximum of 100°F. The unit should have
access to electrical service, a supply of ordinary tap water, and a drain
line for waste water to sewer. The humidifier should not be mounted on
hot surfaces.
1. Mounting The Humidifier
The EHU-600 Series is intended to be mounted on a wall by means of
3/8" diameter lag screws or other suitable fasteners capable of
supporting the maximum operating weight of the humidifier.
Model EHU-600: Making sure the humidifier is level, hold it against the
mounting surface to mark the hole pattern. Make sure the screws will
go into studs or other sturdy structure. Fasten the humidifier to the wall
using the four 3/8" x 1 1/2" lag screws provided (See Fig. 4-3).
Models EHU-601 and EHU-602: Fasten the mounting bracket (see Fig.
4-2 and 5-1) to the wall with the two 3/8" x 1 1/2" lag screws provided.
Make sure the screws will go into studs or other sturdy structure. Hang
the humidifier cabinet on the mounting bracket. Install the #8 x 1/2" self
tapping screw from inside the humidifier cabinet so that it goes through
the holes in the cabinet and the mounting bracket. (Model EHU-602
has two screws). This locks the cabinet to the mounting bracket.
2. Electrical Wiring
All wiring installations must be made in accordance with local
codes. Refer to the capacity chart or the name plate on the unit for
4
Installation and Maintenance
EHU-600 Series Humidifiers
recommended branch wire and fuse. See Sections 7, 8 and 9 for
control wiring information. A complete wiring diagram as shown in
Section 11 is located inside the door of the humidifier.
Wiring to the low-voltage controls should not run in the same conduit as
the power supply wiring because faulty signals could result. Shielded
cable is recommended.
8-7/16
1/4
2 x B1/4
13
5 x B7/16
Important: Please observe the following:
a. Make certain there is a manually operated interlocking circuit
breaker or safety switch (not furnished) in the electric power
supply Located close to and within sight of the
humidifier.
b. Disconnect the electric power supply at this circuit breaker or
switch whenever the unit is inspected or serviced. Do not use
the switch on the humidifier because this switch
disconnects the steam generator tank only.
c. The voltage and phase of the unit must correspond to the
available voltage and phase.
d. The fuse main breaker must be of sufficient size to handle the
maximum fuse rating as indicated on the specification label on
the unit.
e. Ground the humidifier cabinet; a ground lug is provided in
the wiring compartment.
f. Use only wire with copper conductors rated 90oC or higher
for high voltage and grounding.
g. Avoid running high voltage wire next to PC board. Use bottom
knockout for high voltage wire inlet.
1-1/2
2-15/16
6-15/16
12
16
29-7/8
12
7/16
EHU-602
8-7/16
B1/4 1/4
2 x B7/16
11/32
1-1/2
7/16
16
16-7/8
7/16
EHU-601
Figure 5-1: Mounting Brackets and
Bolt Locations
3. Water Fill Supply
a. Only ordinary (potable) tap water should be used. Do not use
brackish or contaminated water.
b. Softened water may not be suitable. The softening process
can produce treated water with conductivity too high.
c. Demineralized, deionized or distilled water is not recommended
unless it is blended with tap water. Consult factory if you have
one of these water supplies.
d. Humidifier maintenance and performance can be affected by
water quality. Ideal water conductivity is 200 to 400 micromhos.
Depending on the application (voltage, capacity, etc.), water
conductivities between 50 and 800 micromhos have been used
successfully. Please consult factory if micromhos are over
800. If unsure of water conductivity, Armstrong will test free of
charge. Consult factory.
e. Connect the water supply to the 3/8" tube compression fitting
on the fill valve adapter.
f. Connect the unit to the building water supply (20 to 125 psig
pressure). Install a shut-off valve near the humidifier.
5
Installation and Maintenance
EHU-600 Series Humidifiers
Use two nuts to hold
power lead terminal – Use
TWO wrenches to tighten
this joint.
4. Connect Drain
Connect to a suitable waste draining system, an open drain is recommended. Local plumbing codes may specify details of this connection.
Be sure the drain line is well pitched (recommend 1" per foot) and is
minimum 1" size copper pipe. Do not use PVC pipe. Drain water is hot.
Drain the water where it will not present a hazard to personnel. Be sure
the cabinet drain (EHU-601/602 only) has a 6" water seal ("P" trap). Note:
A special EPROM is available to temper drain water to 160oF or lower.
Consult factory.
Leave space here.
This nut should be
only snug – do not
over tighten.
Figure 6-1: Steam Generator Tank
Connections
Model EHU-600: Steam generator drain and cabinet drain are the same,
1" O.D. A short piece of 1" I.D. clear hose is provided.
Steam Generator Tank
Be Sure Feet Set
In Cabinet Firmly
& Level
Models EHU-601 and 602: Steam generator drain is 3/4" NPT. Cabinet
drain is 5/8" O.D. (See Section 13 Submittal Drawing).
5. Install Steam Generator
O-Ring Forms
Water Tight Seal
Tank Drain Adaptor
Figure 6-2: Generator Tank Installation
Model EHU-600: The steam generator is shipped installed on the
EHU-600 model. Using wrenches, be sure steam generator tank connections are installed and tightened according to the tank label (see Fig. 6-1).
Models EHU-601 and 602: The steam generator(s) is shipped
separately on the EHU-601 and 602 models. Make sure the O-ring is
properly placed in the tank drain adaptor (see Fig. 6-2). Insert the bottom
center connection of the steam generator into the drain adaptor. Connect
the push-on socket plug electrical leads to the electrode connectors
located on top of the steam generator (see Fig. 6-3). Make sure the pushon plugs are tight (see Fig. 6-4). Remember, a loose joint is a hot joint.
Tank
Electrode
Figure 6-3: Electrode Connector
NOTE: Please consult factory for duct applications offering high static
pressure (4" W.C. or greater or high velocity ducts >2000 FPM).
6. Install Steam Dispersion Tube
a. Verify that the proper length and type of steam dispersion tube
has been selected. See Chart 6-1 for proper dispersion tube
lengths. The standard dispersion tube has a built-in slope to allow for
gravity drainage of condensate back to the steam generator (see
Fig. 7-1). When the dispersion tube capacity is greater than 40
lbs/hr the steam flow rate is too high to allow for gravity drainage
and the EHU dispersion tube with 1/2" O.D. drain tube must be
used (see Fig. 7-2).
Wire
Tighten with
1/8” Allen Wrench
Brass Connector
Tighten by
Clamping with Pliers
Unscrew Plastic Cover
Figure 6-4: Electrode Connector
Push on Plug
Model EHU600, 601 & 602
D-1
D-1.5
D-2
D-3
D-4
D-5
D-6
Length
Duct Width
O.D.
L (cm)
Min.
Max.
1-1/2" (38) 12" (30) 11" (28) 16" (41)
1-1/2" (38) 18" (46) 17" (43) 22" (56)
1-1/2" (38) 24" (61) 23" (58) 34" (86)
1-1/2" (38) 36" (91) 35" (89) 46" (117)
1-1/2" (38) 48" (122) 47" (119) 58" (147)
1-1/2" (38) 60" (152) 59" (150) 70" (178)
1-1/2" (38) 72" (183) 71" (180) 82" (208)
Chart 6-1: Selecting Proper Steam
Dispersion Tube
For dispersion tube without drain: Cut a 1 5/8" diameter hole in
the duct (template provided). See Figure 7-3A.
Weight
lbs. (kg)
2 (1)
2 (1)
3 (1.4)
4 (2)
4 (2)
5 (2.3)
6 (3)
For the dispersion tube with drain: Cut hole in duct as shown in
Figure 7-3B. Connect 1/4" pipe or 1/2" O.D. tubing to the drain
tube. A template is included for cutting holes in the duct.
b. Select a location on the duct that provides adequate length for
vapor mixing and the shortest connection length to the humidifier.
If steam piping run is more than 20 feet, install a "P" trap drain
every 20 feet (see Fig. 7-5). Maximum piping run is 40 feet.
6
Installation and Maintenance
EHU-600 Series Humidifiers
1-3/8" O.D. (1-1/4" Nom.)
Copper Tube
Steam Dispersion Tube
Hose Clamps
HOLES UP
Built In Pitch
Insulation
Hose Cuff
"Up" Label
Front
View
Figure 7-1: Connection at Duct
Preferably the location should be 6 inches down stream and/or 10 feet
upstream from any dampers, vanes, bends in the duct, or controllers
(i.e. high limit stat). Do not install the dispersion tube into ducts in which
airflow exceeds 2,000 FPM. Do not restrict airflow in ducts with a depth
of 8 inches or less. Avoid placing manifold in downward, high velocity
airflow as dynamic air pressure will restrict steam flow.
The preferred installation of the dispersion tube is above the humidifier
as shown in Figure 7-2. This allows for gravity drainage of condensate
back to the humidifier. Figure 7-4 shows the correct installation when
the steam dispersion tube is below the humidifier. If this installation is
used, a 1 1/4" copper tee may be used for the drain connection (see
Fig. 7-5).
6.00
Holes in
Manifold to
be installed
in "UP"
position.
Ø .22
4 places
6.00
5.25
Duct above outlet
Outlet
Ø 1.75
Hole in
duct
5.25
6" Water
Seal
For steam capacity
40 lb/hr or less
EHU
6.00
Ø.22
4 places
R.88
Floor
Drain
6.00
5.25
3.50
Figure 7-3A: For Dispersion Tube
Without Drain
2.00
3.50
1.00
Figure 7-2: EHU Dispersion Tube
with 1/2" O.D. Drain Tube (For More
Than 40 lb/hr Capacity per Tube)
5.25
R.37
Hole in duct
1.50
Figure 7-3B: For Dispersion Tube
With Drain
For steam capacity
above 40 lb/hr
Hose Clamp
Alternate Method:
1-1/4” Copper Tube
Soldered into Tee
Dispension Tube
Steam Hose
Hose
1-1/4" Copper Tee
Soldered Joints
Reducer
1/2" or 3/8"
Copper Tube
6" Water seal
6"
Up
See Fig. 7-5
Figure 7-4: Disperson Tube
Below Steam Outlet on Humidifier
To Drain
Figure 7-5: 1-1/4" Copper Tee for
Drain Connection
c. Insert the dispersion tube into the duct so the holes face
upward. Never install the tube with the holes facing downward.
Fasten the mounting plate to the outside of the duct with sheet
metal screws. If the dispersion tube is 36" long or more, support
the far end with threaded rod or similar means.
7
Installation and Maintenance
EHU-600 Series Humidifiers
d. Connect the dispersion tube to the steam generator using
minimum 1 1/4" nom. (EHU-600) or 1 1/2" (EHU-601/602) size
hard copper tube (customer supplied) and the two short hoses
supplied with the humidifier. See Figures 7-1 and 8-1. Insulate
the copper tube to minimize condensation. Long runs of pipe
and/or high duct static pressure may require 1 1/2" or 2" copper
pipe. See Figure 8-6.
1-3/8" O.D. (1-1/4" Nom.)
Copper Tube
Insulation
EHU
Cabinet
Top
Hose Clamps
If the optional 10 ft. flexible steam hose is used, cut the steam
hose to length as required. Wipe out the inside of each hose end
before installing. Connect the cut end of the hose to the dispersion
tube. Tighten all hose clamps.
Rubber Hose Cuff
Steam Generator Tank
Figure 8-1: Connection at Unit
e. If duct static pressure and piping back pressure exceeds 4" W.C.
please consult factory for special mounting procedures.
Steam hose or pipe must be free of loops, kinks, and sags to
allow for gravity drainage of condensate. (Provide pitch of 1"
per foot.) Hose supports may be required to accomplish this.
GND
4-20 mA Stat.
+Input
500 OHM Input
Impedence ON
4-20 mA/2-10V
Stat. Selection
OR
+5VDC
BLACK
2-10 V Stat.
GND
WHITE
+INPUT
RED
HUMIDITY
INCREASE
Figure 8-2: 4-20 Milliamps Humidistat
2-10 Volts Humidistat
0 – 135 OHM
STAT.
AMW PART NO.
A-8821
Please consult factory for additional information on wiring
A18609, A18610, or A17888 Armstrong Humidistats.
Opens with Increase
in Humidity
+5VDC
Brown
+Input
Orange
Figure 8-3: 0-135 Ohms Humidistat
Common
ON/OFF Stat.
AMW Part No.
A-8581 or
A-8581-A
White
1.9-3.9 Vdc. Input
Green
12 Vac Power
Black
25
Armstrong
26
Solid State
27
Humidistat
AMW Part No.
C-1471 or
C-1472
Figure 8-4: On/Off Humidistat
Figure 8-5: Armstrong Humidistat
Figure 8-6:
Pressure Loss in Copper Pipe
(40 Feet Equivalent Run)
Lb. / Hr. Steam
7. Control Humidistat
The Series EHU-600 is compatible with any humidistat with the following characteristics:
NOTE: Use of shielded wire or wiring in conduit is recommended for
control wiring.
a. 4-20 Milliamps, See Fig. 8-2 for wiring instructions. Note: Printed
Circuit Board has 500 ohm impedance for this type input signal.
Some 4-20 inputs may require a floating ground. Change stat
grounding selector on PC Board. See Figure 9-1.
b. 2-10 Volts, See Fig. 8-2 for wiring instructions. Note: Printed Circuit
Board has 500 ohm impedance for this type input signal. The load
resistor may be removed to increase input impedance, consult factory.
c. 0-135 Ohms, See Fig. 8-3 for wiring instructions.
d. On/Off, See Fig. 8-4 for wiring instructions.
e. Armstrong Humidistat. See Fig. 8-5 for wiring instructions.
8
Installation and Maintenance
EHU-600 Series Humidifiers
Test
Capy Step
Normal
The EHU-600 as shipped, is usually set to accept input signals from
the Armstrong control humidistat. To adapt the EHU-600 to a different
type of control humidistat (with characteristics as listed above) jumper
BJ2 must be changed on the printed circuit board (See Fig. 9-1). For
the Armstrong humidistat select the jumper position labeled 1.93.9V. If the desired humidistat has the characteristics 4-20 milliamps
or 2-10 volts, change the jumper position to the position labeled 2-10V/
4-20MA. If the desired humidistat has the characteristics on/off or
0-135 ohms, change the jumper to the position labeled 0-135Ω ON/Off.
Make sure main power is off when changing any PC board jumper
setting. See the troubleshooting section of this manual for additional
information on humidistat wiring.
Capacity Stepping
Selector
Display Connector
Socket
Stat Grounding
Selector
GND
Float
1.9-3.9 V
2-10V-4-20 MA
0-135 v On/Off
Stat Type
Selector
MCM Header
Selecting The Proper Location: The control humidistat should be
located where it will be exposed to the average air condition of the
space to be humidified. Avoid areas of restricted air circulation, or locations where the sensor will be subjected to air drafts, localized heat, or
moisture sources such as coffee machines, computer blower outlets,
doors to other rooms, or windows that can be opened.
Figure 9-1: Location of Selector Pins
on Printed Circuit Board
Mounts
on std.
2'' x 4'' box
(screws
provided)
4-3/8''
Wall-mounted control humidistats (Armstrong Part C1471) are
usually installed 4 ft. to 5 ft. above floor level. Often, the best location
is beside a thermostat that controls temperature in the same space
that is to be humidified, if that location meets the above criteria.
Duct-mounted control humidistats (Armstrong Part C1472) are also
available for installation where sensing and control from return air
or exhaust air ducts is preferable.
Mounting The Armstrong Control Humidistat
Sensor
2-7/8''
Caution: Do not check humidistat circuit with ohmmeter or direct
current with sensing element installed. Circuit may be checked
without sensor installed.
1-5/8''
Figure 9-2: Wall Mounted Control
Humidistat
2-7/8''
4-3/8''
3-1/2''
1-1/4'' Max.
Duct Mounted Control Humidistat. The sensor is mounted on the
end of the tube extending into the duct – not beneath the humidistat
cover. The duct mounted control humidistat requires a 1 1/4" diameter
hole in the side of the duct. See Fig. 9-3. See Figure 10-3 or 8-5 for
wiring terminals and overall wiring diagrams.
4-1/16''
Sensor
3-5/8''
Wall Mounted Control Humidistat. The wall mounted unit is designed
to mount on a standard electrical outlet box. Mounting screw holes are
provided in the top and the bottom of the back plate. See Fig. 9-2.
10''
Figure 9-3: Duct Mounted Control
Humidistat
Operation And Adjustment Of The Armstrong Humidistat.
To set the Armstrong modulating humidistat to maintain a desired
relative humidity, remove the outer plastic cover and verify that the
number/color coded sensor element installed is in the RH control range
desired (see Fig. 10-1). Figure 10-2 specifies the number/color code
and corresponding humidity set point control range for each sensing
9
Installation and Maintenance
EHU-600 Series Humidifiers
element. (Figure 10-2 can also be found on the inside of the humidistat
cover.)
Set Points
Humidistat
Element
Figure 10-1: Armstrong Humidistat
To set the RH control point within the range of the sensing element, the
jumper wire must be attached to the proper set point pin. There are
nine numbered pins spaced vertically on the right hand side of the
humidstat circuit board; the jumper wire attaches to one of these. By
using Figure 10-2, select the proper pin number to correspond to the
percentage that is to be maintained in the space.
For example, assume that 40% RH is the desired condition and that
the orange colored sensor (15-1213) is in its place in the controller.
From Figure 10-2, it is seen that the horizontal line at 40% intersects
the angular line labeled "orange" closest to the vertical line extending
up from the "5". Once the jumper wire is set to pin 5, replace the cover.
Now the humidstat can control the humidifier steam output at the proper
modulated rate to maintain 40% RH.
The humidstat will send a 1.9 to 3.9 Vdc signal to the humidifier as the
space humidity drops from 42.5 to 37.5% RH (+/- 2.5% RH throttling
range). As the humidistat signal varies from 1.9 to 3.9 Vdc the
humidifier demand signal varies from 0 to 100%. For input signals
below 1.9 Vdc the demand stays at 0% and for signals above 3.9 Vdc
the demand stays at 100%.
Figure 10-2: Control Range for
Sensing Elements
Figure 10-3: Wiring Diagram
8. High Limit Duct Humidistat
A duct mounted High Limit Stat (Armstrong Part A8581) is recommended
as a precaution against localized saturation in the duct. It is an on-off
controller that opens the contact on a rise in humidity (opens on fault).
See Figure 10-3 for wiring terminals and overall wiring diagrams.
Controlling Humidistat
In Return Duct or Room
AMW
C-1471
or
C-1472
Fan Interlock
(i.e. Pressure Switch)
Normally Open
13
22
6
7
3
23
2
24
WHITE
White
GREEN
Green
Black
BLACK
Orange
ORANGE
Brown
BROWN
10
High Limit
Humidistat
Installation and Maintenance
EHU-600 Series Humidifiers
It should be mounted 6 to 10 feet downstream
from the steam dispersion tube (see Fig. 11-1). The
high limit stat must be upstream of filters, silencers,
takeoffs, etc. since these devices can reduce duct
humidity and prevent the high limit stat from doing
its job. Complete mounting instructions are contained
in the High Limit Stat package.
Air Flow
High Limit
Humidistat
Dispersion Tube
Duct
NOT LESS THAN 6 FEET, NOT MORE THAN 10 FEET
Figure 11-1: High Limit
Duct Humidistat
9. Fan Interlock Switch
A fan interlock switch is recommended to deactivate the humidifier when
there is insufficient air flow in a duct system. A duct pressure switch is
preferred as a fan interlock device. The pressure switch should open
on insufficient air flow (opens on fault). See Figure 10-3 for wiring
terminals and overall wiring diagrams. Complete installation and
wiring instructions are contained in the duct pressure switch package.
Armstrong Pressure Switch: (Armstrong Part A9023) All Pressure and
electrical connections and set point adjustments are on side for each
installation. Temperature limit: 32°F. to 180°F.
Maximum surge pressure: 10 psig Rated pressure: 45" H2O
Pressure connections: 1/8" NPT Operating range: 0.07 to 0.15" H2O
Installation:
a. Select a location that is free from excessive vibration, corrosive
atmosphere and within temperature limitations.
b. Connect switch from pressure source with tubing (1/4" O.D.
is recommended) to high pressure port. The low pressure port
is left open to atmosphere.
Note: Above procedure is for downstream side of fan
installation. For fan suction side installation, see instructions
accompanying switch.
c.
Electrical connections to the switch are provided by means of
screw terminals marked common and normally open. The
normally open contacts close when pressure increases beyond
the set point.
d. Complete instructions are contained in the pressure switch
package.
Note: Limit switches (high limit and fan interlock switches) open
on fault.
11
Installation and Maintenance
EHU-600 Series Humidifiers
10. Wiring Diagram
Figure 12-1: EHU-600 Wiring Diagram
12
Installation and Maintenance
EHU-600 Series Humidifiers
11. Capacity Chart
Chart 13-1: EHU-600 Series Capacities and Nominal Amperage Ratings
Output lb./hr. (kg/hr.) @ Voltage
*
Nom
Amp
Rating
MCM
Module
Recommended
Branch Circuit
Wire
Fuse
Single Phase
120
208
Three Phase
240
277
208
240
346 1
380
415 2
480
600
Model EHU-600 Humidifiers (One Steam Generator)
7.0
7
14
15
2.1(.9)
3.7 (1.7)
4.3 (2)
5 (2.3)
6 (2.7)
7 (3.2)
12 (5.5)
15 (6.8)
18 (8.2)
10.9
6
14
15
3.3(1.5)
6 (2.7)
7 (3.2)
8 (3.6)
10 (4.6)
12 (5.5)
18 (8.2)
23 (10.5)
29 (13.2)
14.6
1
15
20
4.5(2)
8 (3.6)
9 (4.1)
10 (4.6)
13 (5.9)
15 (6.8)
24 (11)
31 (14)
39 (17.8)
18.2
2
10
25
10 (4.6)
11 (5)
13 (5.9)
17 (7.7)
19 (8.7)
30 (13.7)
38 (17.3)
21.9
3
10
30
12 (5.5)
13 (5.9)
15 (6.8)
20 (9.1)
23 (10.5)
37 (16.8)
32.7
4
8
45
17 (7.7)
20 (9.1)
23 (10.5)
30 (13.7)
35 (16)
36.3
5
8
50
19 (8.7)
22 (10)
26 (11.8)
33 (15)
38 (17.3)
Model EHU-601 Humidifiers (One Steam Generator)
18.2
2
10
25
10 (4.6)
11 (5)
13 (5.9)
17 (7.7)
19 (8.7)
28 (12.8)
30 (13.7)
33 (15)
21.9
3
10
30
12 (5.5)
13 (5.9)
15 (6.8)
20 (9.1)
23 (10.5)
33 (15)
37 (16.8)
40 (18.2)
38 (17.3) 48 (21.9)
46 (21)
58 (26.4)
32.7
4
8
45
17 (7.7)
20 (9.1)
23 (10.5)
30 (13.7)
35 (16)
50 (22.8)
55 (25)
60 (27.3)
69 (31.4)
86 (39.2)
36.3
5
8
50
19 (8.7)
22 (10)
26 (11.8)
33 (15)
38 (17.3)
55 (25)
61 (27.8)
66 (30)
77 (35)
96 (43.7)
42.0
8
6
60
22 (10)
26 (11.8)
30 (13.7)
38 (17.3)
44 (20)
64 (29)
70 (32)
77 (35)
89 (40.5)
95 (43.3)
45.0
9
6
60
24 (11)
28 (12.8)
32 (14.6)
41 (18.7)
48 (21.9)
69 (31.4)
75 (34)
82 (37.3)
48.0
10
6
70
25 (11.4)
29 (13.2)
34 (15.5)
44 (20)
51 (23.2)
73 (33.2)
80 (36.4)
88 (40)
36.4
2
8
50
19 (8.7)
22 (10)
26 (11.8)
33 (15)
38 (17.3)
55 (25)
61 (27.8)
66 (30)
77 (35)
96 (43.7)
43.8
3
6
60
23 (10.5)
27 (12.3)
31 (14)
40 (18.2)
46 (21)
67 (30.5)
73 (33.2)
80 (36.4)
93 (42.3)
116 (53)
65.4
4
3
100
35 (16)
40 (18.2)
46 (20.9)
60 (27.3)
72.6
5
3
100
39 (17.8)
44 (20)
51 (23.2)
66 (30)
Model EHU-602 Humidifiers (Two Steam Generators)
69 (31.4) 100 (45.5) 109 (49.6) 119 (54) 138 (62.8) 173 (79)
77 (35)
111 (50.5) 121 (55) 133 (60.5) 153 (69.7) 192 (87.4)
84.0
8
2
125
45 (20.5)
51 (23.2)
59 (26.9)
77 (35)
89 (40.5) 128 (58.3) 140 (63.8) 153 (69.7) 177 (80.6)
90.0
9
2
125
48 (21.9)
55 (25)
64 (29)
82 (37.3)
95 (43.3) 137 (62.4) 150 (68.3) 164 (75.7) 190 (86.5)
Notes:
(1) 346 volt units require 346/200 volt 4 wire system. (2) 415 volt units require 415/240 volt 4 wire system.
KW rating = humidity output (lb./hr.) x 0.345 (for energy calculations only; not for branch circuit sizing).
*Nominal Amp Rating is for breaker sizing and UL purposes only. Average operating amperage is 88% of normal rating.
Capacitieis listed in table are based on average amperage draw.
12. Physical Data
Chart 13-2: Series EHU-600, EHF-2 and EHF-3 Fan Packages
Materials
Generator Tank
Polypropylene
Cabinet
Steel-18 GA with Epoxy Enamel Coating
Electrodes
Type 430 Stainless Steel
Hose Cuffs
EPDM Rubber
Duct Model
Disperson Tube
Type 18-8 Stainless Steel
Area Fan Unit Model
EHF-2,3 Cabinet
Steel –18 GA with Epoxy Enamel Coating
EHF-2
115 VAC, 60 Hz, 1.3 amp
Blower Fan
280 CFM @ 1380 RPM
EHF-3
115 VAC, 60 Hz, 2.9 amp
Blower Fan
465 CFM @ 1530 RPM
13
Model No.
EHU-600
EHU-601
EHU-602
EHF-2
EHF-3
Weights
Approximate
Shipping
lb
kg
60
27
76
35
87
40
33
15
34
15.5
Maximum
Operating
lb
kg
80
36
104
47
145
66
32
14.6
33
15
Installation and Maintenance
EHU-600 Series Humidifiers
13. Submittal Drawings
EHU-600
Chart 14:1 Dimensional Data
"A"
"B"
"C"
"D"
"E"
"F"
"G"
"H"
"I"
"J"
"K"
"L"
"M"
"N"
"N"
"P"
"Q"
"R"
"S"
Width
Height
Depth
Tank Drain (Side)
Tank Drain (Front)
Cabinet Drain 5/8" OD
Tank #2 Drain (Front)
Steam Outlet #1
Steam Outlet #2
Water Supply* (Side)
Water Supply* (Front)
Electrical Supply (Side)
Electrical Supply (Front)
Fan Height (EHF-2)
Fan Height (EHF-3)
Front Clearance
Left Clearance
Bottom Clearance
Right Clearance
in
18
23
111/2
65/8
105/16
N/A
N/A
121/2
N/A
81/4
151/2
31/8
41/2
13
16
18
4
5
4
mm
457
584
292
168
262
N/A
N/A
318
N/A
210
394
80
114
330
406
457
102
127
102
EHU-601
in
18
281/2
1311/32
63/16
81/4
111/2
N/A
111/2
N/A
913/16
35/16
2
21/2
N/A
EHU-602
mm
457
724
339
157
210
292
N/A
292
N/A
249
84
51
64
N/A
in
31
281/2
1311/32
63/16
81/4
18
213/16
111/2
13
913/16
35/16
2
21/2
N/A
mm
787
724
339
157
210
457
538
292
330
249
84
51
64
N/A
1-1/2” I.D.
Hose Cuff
Remote Installation Only
24
24
5
4
610
610
127
102
24
24
5
4
610
610
127
102
Figure 14-1 Model EHU-600
(Front and Side View)
* Water Supply Conn. 3/8" Compression.
Unit is designed to mount on 16" centers.
2 lag screws are provided for EHU-600.
2 lag screws & bracket are provided for EHU-601 & 602.
1Z\x" I.D.
Hose Cuff
3/4" NPT
Tank
TANKDrain
DRAIN
5/8” O.D.
Cabinet Drain
5/8'' O.D. Cabinet
Drain
R
3/4'' NPT
Tank Drain
Figure 14-2: Model EHU-601
(Front and Side View)
Figure 14-3: Model EHU-602
(Front View)
14
Installation and Maintenance
EHU-600 Series Humidifiers
Principle of
Operation
1. Operation
The Armstrong EHU-600 Series electronic steam humidifier
converts ordinary tap water to steam and distributes it within
the air being humidified to bring the relative humidity up to the
desired level. It is the ideal solution for providing humidification where no steam is available or where a steam source is
too remote for easy or economical piping. The Armstrong
EHU-600 Series consists of three models: The EHU-600, 601
and 602. The maximum capacity of the series is 192 lb/hr.
The humidity demand, sensed by the humidistat, is indicated
by the EHU demand meter. The microprocessor converts this
demand signal into an amperage requirement. The power
contactor closes, applying voltage to the electrodes, and the
fill valve begins to fill the tank.
Figure 15-1: 100% demand. Filling with
water low, increasing steam output.
Water enters the bottom of the steam generator tank and rises
until it reaches the electrodes. Upon contact, electrical current
flows through the water, causing it to boil and produce steam
(Fig. 15-1).
When the water level rises, as shown in Fig. 15-2, increased
electrical current flows through the water, producing more
steam. This increase will continue until the required output
of steam (i.e. amperage requirement) is reached.
Figure 15-2: 100% demand. Fill valve
cycling to maintain output. High water
level. High, constant steam output.
At this point, the fill valve will cycle off and on to maintain the
required amperage. When the humidistat senses the added
moisture in the air, the demand for humidity begins to drop. As
the demand drops, the output of the unit is modulated down by
boiling away water and not filling, allowing amperage to
decrease, thereby reducing the steam flow. The fill valve can
then cycle at the lower steam output (amperage) requirement.
Fig. 15-3 shows what happens when the humidistat demand
signal drops below a minimum demand: The contactor is
de-energized, and steam output stops.
Steam output may also be stopped by a duct high-limit
humidistat or a fan interlock switch. These devices prevent
excess moisture and condensation in the duct. If these devices
open, the Tank Off light will illuminate and the fill will turn off.
Figure 15-3: No demand. Contactor opens.
No steam output.
A high-water float switch prevents water carryover into the duct
due to too high a water level in the tank. When the high water
level is reached the TANK FULL light comes on and the fill
valve is blocked until some water is boiled away and the
water level drops. This is not uncommon on startup. If the
TANK FULL light is on continuously during normal service
then the tank probably needs cleaning.
15
Installation and Maintenance
EHU-600 Series Humidifiers
An automatic drain cycle blows down mineral-laden water to increase
tank life and reduce maintenance requirements. If the water in the
steam generator is not very conductive it will reach the high water
level. The drain duration is adjusted based on how often the high water
level is reached.
An overcurrent protection circuit will drain water from the tank to reduce
current flow and then de-energize the contactor to stop current flow if
overcurrent still exists.
The EHU-600 Series has a patented self-regulating maximum output
feature that eliminates manual adjustment and improves humidity
control. In low demand situations, units with greater capacity can quickly
overshoot setpoint because a fraction of the output satisfies the
requirement. This on-again/off-again behavior is called "hunting" because
the unit has difficulty attaining setpoint. The EHU-600 Series
automatically adjusts maximum output up or down depending on the
humidity demand history. If this feature is not desired it can be easily
over ridden by changing the position of jumper BJ3 on the printed
circuit board from CAPY STEP/NORMAL to CAPY STEP/TEST.
Make sure main power is turned off whenever changing jumpers
on PC board.
16
Installation and Maintenance
EHU-600 Series Humidifiers
2. Suggested Specification
Steam humidifier for distribution of humidity (steam vapor) into air handling system or directly into space
shall be of the self-contained, electronically controlled design.
a. Humidifier shall generate steam from ordinary tap water.
b. Humidifier(s) shall have all internal components contained in a steel cabinet with a key-locked
access door to prevent unauthorized access.
c.
Humidifier(s) shall be UL and CUL listed.
d. Humidifier shall have modulating control to provide 10 to 100% capacity.
e. Maximum capacity of humidifier shall self regulate with no manual adjustment.
f.
Humidifier shall have steam generator(s) that can be taken apart for inspections and cleaning, or
if needed, replacement of internal parts.
g. Drain cycle will be self regulating for automatic control of mineral (conductivity) buildup.
h. Humidifier shall have programmed diagnostics to confirm that input and output circuits are functioning.
i.
Humidifier shall incorporate a demand meter to display status of main control humidistat signal.
j.
The electronic circuit shall provide automatic protection from excessive current and high water
overflow.
k.
The humidifier fill water line(s) shall have an air gap to prevent backflow (syphoning) of contaminated water into the water supply system.
l.
Humidifier shall incorporate electrical terminals for installation of controlling stat, duct high-limit
stat and fan interlock switch.
m. Humidifier shall be supplied with stainless steel steam dispersion tube(s) which provide uniform
steam distribution over the entire tube length and shall be supplied at various lengths (through
6 feet) to adequately span the widest dimension of the duct.
n. When applicable, humidifier(s) shall have provisions for discharging steam vapor directly into
room area using factory available fan distribution units as an accessory. These units shall be
designed for either remote mounting or fit directly on top of humidifier.
o. Humidifier shall be supplied with two hose cuffs for connection to hard copper tube (customer
supplied). 1 1/2" ID flexible rubber hose shall be available as an optional item.
p. Humidifier shall be supplied with a humidistat capable of modulating the steam flow, or be capable
of working with the following common control signals without factory modification: 0-135 ohms,
2-10 Vdc, 4-20 milliamp and on/off control (SPST relay).
17
Installation and Maintenance
EHU-600 Series Humidifiers
3. Instrument Panel
"Power" Light – Indicates when the electrical supply is energized.
"Fill" Light – Indicates when the fill valve is energized to add water to
the steam generator.
"Drain" Light – Indicates when the drain valve is energized to drain
water from the steam generator. Note: Drain light does not turn on
when manual drain switch is energized.
"Tank Full" Light – Indicates that the water level in the generator has
risen to the high water float switch. The electronic controls automatically
interrupt the fill cycle to prevent overflow. This may be a normal
occurrence with a brand new or recently cleaned steam generator,
especially if the water conductivity is low and amperage requirements
are high. After a few days of operation the water level should drop
below the high water level due to mineral (conductivity) build up in the
tank. To temporarily increase tank water conductivity a small amount
of salt can be added to the tank water. After extended use, repeated
lighting of the Tank Full light indicates that, in spite of periodic draining
of mineral-laden water, the steam generator should be inspected,
and either cleaned or replaced.
Note: When the Tank Full light is on, the unit may not be able to
generate a sufficient supply of steam to satisfy the demand.
"Tank Off" Light – Indicates when power to the generator has been
interrupted. This may be due to low demand, high duct humidity
interlock, fan interlock, high current, or failed drain system.
"Demand Meter" – Indicates the demand for humidity in relation to the
RH set on the humidistat. The demand meter for the EHU-600 is a
series of 5 LED's which indicate demands of 10%-30%, 30%-50%,
50%-70%, 70%-90%, and 90%-100%.
"Tank On/Off" – Pushing and releasing the top part of the black switch
starts the humidifier or resets the internal overcurrent protection. Pushing
and holding the TANK ON/OFF switch for 15 seconds starts the
diagnostics system. See the section on Maintenance.
Figure 18-1: Instrument Panel
"Manual Drain" – Pushing and holding the bottom part of the black
switch activates the manual drain. Note: Drain light will not illuminate
during the manual drain.
18
Installation and Maintenance
EHU-600 Series Humidifiers
Start-Up
Procedure
The following steps should be performed on all newly installed EHU
Humidifier units to ensure that the humidifier functions correctly.
1. Turn power supply at disconnect off.
2. Open the two doors.
3. Examine the wiring and the components in the electrical
compartment.
4. Check for any loose wires or quick-connect terminals that may have
been pulled loose.

Contactors
Current
Transformers
5. Using a screwdriver, Tighten All Screw Terminals on the power
supply terminal block, ground lug, and contactor (See Figure
19-1) to ensure that no connections have become loose during
shipping.

Low
Voltage
Terminal
Block

Make sure steam generator tank connections are installed and
tightened according to the installation instructions (see pg. 6
installation step 5). Remember, a loose joint is a HOT joint and
could be a fire hazard!
6. Locate the "Low Voltage Terminal Block" (See Figure 19-1).
Power
Supply
Terminal
Block

7. Disconnect the control wiring to terminals 3 and 23 (High Limit
Humidistat) and terminals 2 and 24 (Air Proving Switch), then
jumper them out with the tabs provided, or a short piece of wire.
8. Turn on the water supply – Check for leaks.
9. Turn power supply on. The following should now happen:
Figure 19-1: Electrical Component
Identification
(Model EHU-602 shown)
a. The "Power" and "Tank Off" lights will now be momentarily
illuminated.
b. The "Tank Off" light will go out and the "Fill Light" will go on.
Unit will begin to fill.
c.
Figure 19-2: Humidistat Element
If the unit does not begin filling, force a 100% humidity demand
by removing the humidistat element (See Figure 19-2). The
unit will then start to fill, and the "Tank Off" light will go out. If
not, the humidistat may be wired incorrectly or may not be the
Armstrong humidistat. See troubleshooting section of this
manual for more information on humidistat wiring.
NOTE: If the humidistat is not the standard Armstrong stat,
the method of forcing a demand signal will be different.
Generally, increasing the humidity set point on the humidistat
will generate a demand signal. Check with the control system
contractor for information.
19
Installation and Maintenance
EHU-600 Series Humidifiers
Another method of forcing a 100% demand is to remove the
controller input signal from terminal 6, jumper terminal 13
to terminal 6 with a short piece of wire, and select either
1.9-3.9Vdc or on/off control setting on the main circuit board.
10. While the tank is filling, open terminals 2 and 24 with a screwdriver, loosening and removing the jumper. The fill will stop and the
"Tank Off" light will come on. Replace jumper; within 10 seconds
the contactor will pull in and the fill will resume.
11. Repeat with terminals 3 and 23. The response will be identical to
Step 10.
12. Let the unit continue to fill and allow to boil.
a. If the water level reaches within 4" of the steam generator
tank top, the high level float switch will block the fill, and
illuminate the "Tank Full" light. This is normal on relatively
pure water, but to complete the start-up testing, push and hold
the drain switch to drain 1/2 of the tank, then, with power off,
add one pinch (1/4 teaspoon) of salt to the fill cup. This should
allow the water to boil by increasing the water's conductivity.
b. If "Tank Full" light illuminates with water level below midway
point in the tank, the back pressure due to duct static or steam
dispersion piping is too high. Consult factory.
13. On typical beginning fill, after the fill stops, using an ammeter, the
tank leads will each be drawing between 35-40% of "nominal amp
rating" at this point. (See unit label for nominal amp rating.)
14. Press the drain switch. Verify that the unit is drawing freely. Be
sure the drain line is well pitched and is 1" size copper pipe. Do
NOTE use PVC pipe.
15. Install the humidstat element, or verify that it is in place.
16. Verify that the humidity set-point is at the desired value.
17. Blow "humidly" on the humidstat element. The following should
happen:
a. The demand meter will go to zero.
b. The unit will shut down, lighting the "Tank Off" light.
c. The unit may energize again after the sensor "dries" out.
The demand meter indicates the humidstat signal, so once
the sensor "dries out" the demand will climb back to 100%
(maybe less if the humidity level is within the control range of
the humidity setting.)
18. Reconnect the air proving switch to terminals 2 and 24. Verify
that the air proving switch is wired to that it opens on no air flow
and is closed with air flow (normally open).
20
Installation and Maintenance
EHU-600 Series Humidifiers
19. Reconnect the high limit stat (if used) to terminals 3 and 23. Verify
that the high limit stat is wired so that it opens at the high limit
setpoint and is closed below this point (normally open).
20. Inspect the steam outlet piping. Verify that there are no untrapped
low spots.
Dispersion
Tube
21. If the dispersion tube is equipped with a drain fitting, verify that it
is working. Look at the tube mounting plate, there is an Armstrong
"A" Logo or "UP" sticker which should be pointing up. If not, the
tube will not drain properly (See Figure 21-1).
Tube
Mounting Plate
Figure 21-1: Tube Mounting Plate
22. When using EHF-2 Fan Package units, the fan must be turned on
for steam to be generated. The fan will stay on when the humidity
demand is satisfied. See IB-96 for complete installation instructions
of the EHF-2 Fan Unit.
23. Turn power off, if humidification is not needed now.
24. Close and lock the doors, and store the key away from the unit.
21
Installation and Maintenance
EHU-600 Series Humidifiers
Maintenance
1. Recommended Maintenance Schedule
1 Week after start up
a. Check unit operation
b. Look in drain pan for leaks.
c.
Check steam piping for leaks.
d. Observe duct low points for signs of poor humidity distribution.
1 Month to 1 year
Clean or replace steam generator and/or electrodes. Be sure
unit is draining freely by pushing and holding drain light during
fill cycles.
2. Water quality and treatment for EHU Series humidifiers
General
Steam generator water levels at given
current and water conductivity
Figure 22-1: Dry, No current
The real reason to acquaint yourself with this material is maintenance.
On poor quality water, EHU Series Humidifiers require more maintenance,
also, your water heater, drinking fountains, washers, etc., so this
maintenance is required when you can least afford to perform it.
Hopefully, understanding the problem and possible solutions will help
avoid problems in the first place.
How water affects the EHU: The EHU is an electrode boiler. When no
water is present, the electrodes are separated by air and no current is
conducted. When water contacts the electrodes, the conductive
minerals in the water allows current to flow. Conductivity is the
measure of how conductive the water is and is measured in micromhos
(µmhos/cm2). The more conductivity, the lower the water level will be
to draw a given current say, 10 amps.
What affects conductivity? Obviously, minerals dissolved in the
water. Pure distilled water is not conductive. This includes deionized
Figure 22-2: Low conductivity, 10 amps and reverse osmosis diffusion water treatment. Pure water can't work
in an EHU because it will not allow amperage draw (it's not conductive).
Most tap water is conductive however, so it will work in an EHU. The
type and quantity of minerals can vary greatly depending on the source
of the water (See Chart 23-1).
Figure 22-3: High conductivity, 10 amps
22
Installation and Maintenance
EHU-600 Series Humidifiers
Chart 23-1: Typical Minerals
Found in Water
Constituent or property
Silica (SiO3) ____________
Iron (Fe) ______________
Calcium (Ca) ___________
Magnesium (Mg) ________
Sodium (Na) ___________
Potassium (K) __________
Carbonate (CO3) ________
Bicarbonate (HCO3) _____
Sulfate (SO4) ___________
Chloride (Cl) ___________
Fluoride (F) ____________
Nitrate (NO3) ___________
Dissolved solids ________
Hardness _____________
Color _________________
pH ___________________
River1
Analysis of water, in parts per million,
except for pH and color
Well2
Canal3
5.4
.11
9.6
2.4
4.2
1.1
0
26
12
5.0
.1
3.2
64
34
7
6.9
41
.04
50
4.8
10
5.1
0
172
8.0
5.0
.4
20
250
145
0
7.9
6.6
.11
83
6.7
12
1.2
0
263
5.4
20
.2
1.3
310
235
97
7.7
Lake4
11
.10
2.9
9.5
8690
138
3010
3600
10500
668
—
5.8
25000
46
2
9.8
1-Stream in Connecticut 2-Logan County, CO 3-Drainage from Everglades, FL 4-Northcentral North Dakota
The drain cycle: EHU Series humidifiers have a built in blowdown
circuit to intermittently purge mineral accumulations from the water.
This is a bottom blowdown, so if minerals stick to the sides of the steam
generator, they will accumulate. The standard drain interval is every 30
minutes for the EHU-600 and every 15 minutes for the EHU-601/602.
Drain duration is automatically adjusted based on water hardness. If
the water is very hard an increased drainage EPROM may be needed.
Please consult the factory.
Water related maintenance: There are two types of water related
maintenance required in EHU Series humidifiers:
3. Tank Cleaning
The tank is full of white or light brown colored mineral buildup. This
buildup may be anywhere from soft and chalky to rock hard.
Tank cleaning can usually be handled one of five ways:
Figure 23-1: Tank filled with mineral
buildup.
a. Mechanical: Wire brush or scrape electrodes and tank walls
clean. NOTE: If cleaning mechanically it is not necessary to
clean the electrodes to the bare metal. Removal of major
accumulations is the only requirement.
b. Chemical: Commercial Muriatic acid preparations work well
on most accumulations. See Section 3, "Steam Generator
Cleaning Procedure."
Caution: Muriatic acid can cause severe chemical burns if not
handled properly. Wear rubber gloves and eye protection when
using. Read and follow carefully the safety procedures on the
chemical package.
23
Installation and Maintenance
EHU-600 Series Humidifiers
c.
Softening: Water softeners remove calcium and add sodium
which stays in solution instead of plating out. Minerals will drain
out and accumulate less.
Caution: Soft water may be more conductive and does not
allow a protective coating to form on electrodes. Because salt is
infinitely soluble in water the drainage rates required will increase
dramatically. Special EPROMs may be needed. In general avoid using softened water if conductivity is above 250 µmhos/cm2. Expect
to replace electrodes more frequently. Discontinue if any arcing
and/or foaming occurs in tank. (See Electrode Disintegration)
d. Water Purification: If you have pure water available such as:
Deionized water, Reverse Osmosis diffusion water, or distilled
water, they can be blended with tap water or softened water to
reduce the total mineral content. Pure water alone is not conductive enough to pull current. Consult your water purification
equipment vendor for proper blending equipment. Consult the
factory for recommended blend amounts. In general if blending with tap water conductivity of incoming water should be
around 200-300 µmhos/cm2. If blending with softened water
conductivity should be around 100 µmhos/cm2. Too much softened water will cause arcing and foaming in the generator. Watch
the unit closely for a few days to ensure proper operation. The
water is too pure when the "Tank Full" light comes on excessively.
e. Magnetic Treatment: Magnetic coils designed to allow water to
be "magnetized" have been found useful, in some instances, in
reducing mineral buildup in the steam generator. The coil is
inserted in the incoming water line and may or may not be
electrically powered. Best success has been seen on well water
with high amounts of calcium dissolved in it. It's best to use
these on a trial basis at first to determine if there is a benefit
with the water being used.
Figure 24-1: Electrode Disintegration
4. Electrode Disintegration/Replacement
The tank may turn black or red, arcing or flashing may be visible inside
the tank when operating. See Figure 24-1.
Electrode Disintegration: Starts generally due to poor quality water being
present in the steam generator. Poor quality water means water with high
conductivity. Because the water is highly conductive, the EHU operates
with a low water level at normal current. Low water levels mean that the
current is concentrated on a small amount of electrode surface area and
is flowing through very little water. This high amp flow/low water levels is
what usually gets arcing started, besides being very corrosive.
Electrode disintegration is most likely in the following instances:
a. High voltage (especially 480 and 600 volts);
b. Hard water (in excess of 20 grains/gal.);
c. Long drain lines;
d. Low amperage units;
e. Any unit with a plugged drain line;
f. Any unit with a malfunctioning drain valve;
g. Any unit with any of the above on softened water.
24
Installation and Maintenance
EHU-600 Series Humidifiers
Note: Arcing or flashing in the steam generator tank can be caused
by one or more of the following:
1. Poor drainage
2. Abnormal water conditions
3. Dirty tank (needs cleaning)
If you notice arcing, shut the unit off and call the factory before
restarting unit. If water conductivity is higher than 600µmhos/cm2
and arcing is occurring, a special increased drainage EPROM may
be required. Consult factory.
Figure 25-1: Optimum Water Level
Optimum water level: As you are aware by now, water level plays a key
role in EHU Amperage Control. The EHU will change water level
automatically to adjust humidity output. Therefore, to provide optimum
humidity control, the tank water level should be within 2" of the center
of the steam generator.
3. Steam Generator Cleaning Procedure
This procedure is intended as a guide only. Read and follow label
directions on any cleaning product. Check local codes before disposing
of chemicals.
Caution: Muriatic acid can cause severe chemical burns if not handled
properly. Wear rubber gloves and eye protection when using. Read
and follow carefully the safety procedures on the package.
a. Obtain several gallons of muriatic acid. Muriatic acid is a name
for weak hydrochloric acid. It is available in most hardware,
pool chemical, or farm supply outlets.
b. Let steam generator tank cool after removal from EHU unit.
c.
Examine the tank inside by looking down through the steam
outlet (top connection). Be sure the tank is cool.
1. If tank is black or dark brown, it can't be chemically cleaned.
The electrodes may have disintegrated. The tank will
require a thorough cleaning and possibly electrode
replacement.
2. If tank has white/tan/grey mineral accumulations, estimate
how high the tank must be filled with muriatic acid to
dissolve the minerals. Never fill the tank more than 2/3
full.
d. Plug the tank bottom. Move the tank to a location where disposal
and clean up will be easy.
e. Take care to add the acid only to the tank insides. The
outside electrical terminals or metal flange parts may be
damaged by the acid.
25
Installation and Maintenance
EHU-600 Series Humidifiers
f.
Never fill the tank more than 2/3 full. Watch the tank outside
wall for the liquid level. Stop if foaming occurs and fills the tank
more than 2/3 full.
g. The 2/3 full requirement is to keep acid from attacking the
electrical connections inside the top of the tank.
Check for equal spacing, 3 places.
Use these holes for Position No. 1
Position No. 3 Shown
h. Let the tank cleaning action take place for 15 minutes. Drain the
fluid out the tank bottom. Rinse the tank twice with clean water.
i.
Observe the inside to determine if another treatment is necessary.
j.
It is not necessary for the electrodes to be cleaned down to bare
metal. Removal of major accumulations is the only requirement.
k.
Helpful Hints:
Use these holes for Position No. 2
• Keep a rotating spare tank for installation in each humidifier.
Cleaning can be done when convenient, not rushed.
Figure 26-1: Model EHU-601 and EHU-602
3 Ph Electrode Installation
(Top View)
• Check the drain valve, tank drain adapter and tubing for
proper operation and good flow when the tank is drained prior
to removal.
• On EHU-600 models, it is easier to disconnect the electrical
wires back at the contactor, not on top of the steam
generator tank.
l.
Re-install the steam generator tank. Make sure all electrical
connections are tight; see Page 6. Check unit for proper
operation.
4. Electrode Installation
Figure 26-2: Top view
Barrier Assembly
Models EHU-601 and EHU-602 – Three Phase
a. Clean the inside of the steam generator thoroughly and rinse
with clear water.
b. High voltage units are supplied with a barrier/drain screen
assembly in the lower tank half to reduce the possibility of
arcing and increase electrode life. Inspect the barrier/drain
screen assembly and replace if necessary. (See Figures 26-2,
26-3, and 27-1.)
c.
Figure 26-3: Side View
Barrier Assembly
Make sure terminals and contact area on electrode top plates
are clean and free of rust. Wire brush, if necessary. Set the
electrodes in place. Be sure to use the same pair of holes on
all electrodes. If you do not know which position (set of holes)
to use, follow these recommendations (See Figure 26-1).
NOTE: The EHU-600 electrodes are not adjustable in the field.
However, a set of closer spaced electrodes for low water conductivity
are available. Consult the factory or your Armstrong Representative.
26
Installation and Maintenance
EHU-600 Series Humidifiers
Chart 27:1
Position
11/4"
380-600 Volts / high
conductivity water
#3
11/4"
208-240 Volts / high
conductivity water
#2
1"
3
/4"
208-240 volts / medium
conductivity water
208-240 Volts / low
conductivity water
d. Put a stainless steel lockwasher and nut on each stud and
tighten all nuts. (A 7/16" socket on a 6" or longer extensions
makes this easier and safer!)
e. Check the spacings between the electrodes and make sure
they are equal (3 places). Bend the electrodes by hand to
adjust spacings.
f. When reinstalling push pin connector, make sure they are tight.
See Figure 6-3 and 6-4.
Figure 27-1: Three Phase Tank
with Barriers Installed
NOTE: If barriers are used, electrodes must be in #3 position.
Lock washer
& Nut (8 places)
Outer
electrode
Inner
electrode
Jumper
Strip
Panhead
Screw
High Water
Probe
Figure 27-2: Single Phase Electrode
Installation Models EHU-601 and 602
Washer
Voltage / Condition
#3 with
barriers
#1
Flat
Washers
Approx.
Spacing
Models EHU-601 and EHU-602 – Single Phase
a. Clean the inside of the steam generator thoroughly and rinse
with clear water.
b. Set the jumper strip in place first (see Figure 27-2). Then set
the outer electrode in place and install a stainless steel
lockwasher and nut on the three outer studs, install the pan
head screw as shown. Tighten the nuts and screw. (A 7/16"
socket on an extension makes this step, and the next, much
easier and safer!)
c. Set the two flat washers in place as shown. Then set the
inner electrode in place and put a lockwasher and nut on each
of the inner studs. Tighten all nuts.
CAUTION: To ensure proper and safe operation, all parts must
be assembled exactly as shown. Use the high water probe as
a location reference.
d. When reinstalling push pin connector, make sure they are tight.
See Figure 6-3 and 6-4.
Hexnut
O-Ring
Washer
Figure 27-3: Electrode Installation
Model EHU-600
Model EHU-600 – Three Phase
a. Clean the inside of the steam generator thoroughly and rinse
with clear water.
b. High voltage units are supplied with a barrier/drain screen
assembly in the lower tank half to reduce the possibility of arcing
and increase electrode life. Inspect the barrier/drain screen
assembly and replace if necessary.
c. Place a flat washer and O-ring on each 1/4" electrode stud
(see Figure 27-3).
d. The other mounting hole on each electrode is attached to the
tank top with the slotted self-tapping screws. (See Figure 28-1)
e. From the outside, install a flat washer and 1/4" hex nut on each
electrode stud (see Figure 27-3). Tighten these so they are snug.
f. See Section 5 of Installation Procedure (Page 6) for information
on installing steam generator in unit.
27
Installation and Maintenance
EHU-600 Series Humidifiers
Check for equal spacing, 3 places.
Figure 28-1:
Model
EHU-600
3 Phase
Model EHU-600 – Single Phase
a. Clean the inside of the steam generator thoroughly and rinse
with clear water.
b. Place a flat washer and O-ring on each 1/4" electrode stud.
(See Figure 27-3).
c. Outer electrode stud goes in hole marked 1 (see Figure 28-2).
d. Inner electrode and stud goes in hole marked 2.
e. The other two mounting legs on each electrode are attached
to the tank top with the slotted self-tapping screws.
f. From the outside, install a flat washer and 1/4" hex nut on
each electrode stud. Tighten these so they are snug.
Figure 28-2:
Model
EHU-600
1 Phase
Model EHU-600 is shown above. Models EHU-601 and EHU-602
are similar but some part numbers are different.
Parts Description
1. Hose Clamp
2. Fill Valve to Fill Cup Tube
3. Fill Cup to Adapter Tube
4. Fill Cup Overflow Tube
5. Drain "O" Ring Seal
6. Tank Drain Adapter
7. Adapter to Drain Valve Tube
9. Drain Valve
10. Fill Valve
11.
12.
13.
14.
15.
18.
Hose Nut Gasket
Hose Nut Reducer
Lower Tank Half
Tank "O" Ring Seal
Upper Tank Half - 3 Phase
Electrode Assembly 3 Phase
19. Drain Screen
20. Electrode Assembly 1 Phase
28
21. Upper Tank Half - 1 Phase
22. Tank Assembly Complete 3 Phase
23. Tank Assembly Complete 1 Phase
24. V Band Clamp
25. Fill Cup
26. Rocker Switch
48. Float Switch
49. Float Switch Bracket
Installation and Maintenance
EHU-600 Series Humidifiers
Diagnostics
The EHU-600 has a diagnostic function which serves as a troubleshooting aid. The diagnostics will check all the output circuits: fill valve,
drain valve, contactor, and display lights to make sure they are working.
It then shows the status of all input circuits: fan interlock switch, high
limit duct humidistat, high water switch or probe, and humidistat demand
signal.
To initiate the diagnostic routine:
a. Turn water supply off.
b. If the tank contains water, press and hold Manual Drain switch
until the tank is empty. Drain light will not come on.
c. Press and hold the Tank On/Off switch until the Fill light begins
to blink (approximately 15 seconds). The Tank Off light will go
off if it is on or go on if it is off.
d. Release the switch when the Fill light begins to blink. This
signals that the diagnostics routine has begun.
For the purpose of the diagnostic function, the lights on the front panel
of the humidifier correspond to assigned input and output circuits. Note:
The Power light remains on during the whole diagnostic routine and
does not correspond to any circuit.
1. Output Circuits
The first half of the diagnostics routine checks the output circuits. Each
light on the humidifier panel will flash on and off twice, in order, from top to
bottom.
When a light comes on, you will hear the corresponding valve or
contactor open and close. Chart 29-1 shows the output circuits in the
order they are tested.
Chart 29-1
Light
Fill
Drain
Tank Full
Tank Off
Demand Meter
Corresponding Output Circuit
Fill Valve
Drain Valve
No related output(a)
Contactor(s)
No related output(b)
a. The Tank Full light indicates a high water condition. The output
portion of the diagnostics checks whether this light is
functioning.
b. The output portion of the diagnostics indicates whether the
demand meter lights are functioning.
29
Installation and Maintenance
EHU-600 Series Humidifiers
2. Input Circuits
After the output circuits have been checked, the Tank Full light will
begin blinking continuously, signaling the start of the input test. Each
light corresponds to an input circuit. Chart 30-1 shows the input circuits
tested. All are tested simultaneously.
Chart 30-1
Light Not On
Fill
Drain
Tank Full
Tank Off
Demand Meter
Check Input Circuit
(a) High water probe
(b) Fan interlock switch
Blinking indicates input testing
(c) High limit humidistat
(d) Control humidistat
NOTE: The Tank full light will continue to flash during the input test.
a. If light is off, circuit is complete. Check for water in tank or
dirty tank.
b. If light is off, check that fan interlock switch is wired properly.
c. If light is off, check that high limit stat is wired properly.
d. If no demand signal, room is either over-humidified, or stat is
mis-wired, or malfunctioning.
If All the lights are on, then all controls are allowing the humidifier to fill.
In case of component malfunction, consult your Armstrong Representative or the factory for further assistance.
Note: To end the diagnostic routine, push and release the Tank On/
Off switch once. If left in the diagnostic routine for more than 3 minutes,
the DRAIN light will begin to cycle 1 minute off, 3 minutes on.
If the unit is functioning normally, turn the water supply back on. Push
and release the Tank On/Off switch again to start the unit.
During normal operation, if the drain is open (Drain light on) for more
than 3 minutes, the contactors will trip out the unit and turn the Tank
Off light on. This indicates some form of drain system failure (clogged
drain, failed valve, etc.) The unit may be reset only by turning the
main power on and off.
For additional troubleshooting information, please request
Form 903 from factory or call HVAC Application Engineering
at (269) 273-1415 or Fax (269) 273-9500. Visit our web site
www.armstrong-intl.com.
30
Installation and Maintenance
EHU-600 Series Humidifiers
Humidistat
Troubleshooting
If the Armstrong Humidistat is mis-wired Table 31-1 shows the unit
response. * indicates wrong wire connected. W, G, and B stand for
white, green, and black, the wire colors on the humidistat. See Section
7 for more information on control humidistat wiring.
Table 31-1
Terminal
22
6
7
W
G
B
B*
B*
G
W*
G*
G*
W
Demand Meter
Functional Response
Responds to stat normally,
0% with jumper disconnected.
100% with sensor out.
Correct wiring. Unit fills
and drains normally.
W*
G*
5 demand lights flicker with
or without sensor or pigtail
Contactor cycles or
chatters. Unit fills continuously.
B*
W*
5 demand lights flicker with
or without sensor or pigtail.
Contactor chatters
Unit will not fill.
W*
B*
B*
G*
1 or no demand light(s) flicker
with or without sensor or pigtail.
Tank off. Contactor will
not energize. Unit will not fill.
Table 31-2 shows the units response if jumper BJ2 is in the wrong
position and the Armstrong humidistat is wired correctly. See Section 7
for more information on jumper locations and selections.
Table 31-2
Jumper
BJ2 Pin No.
Labeled
Functional Response
4
1.9-3.9
Correct Pin No. Unit
responds normally.
3
2-10V/4-2MA
0% demand. Unit will
not fill. Tank off.
2
0-135 On/Off
Unit responds normally
but over wider %RH range.
31
Installation and Maintenance
EHU-600 Series Humidifiers
ARMSTRONG INTERNATIONAL, INC.
LIMITED WARRANTY AND REMEDY
Armstrong International, Inc. (“Armstrong”) warrants to the original user of those products supplied by it and
used in the service and in the manner for which they are intended, that such products shall be free from
defects in material and workmanship for a period of one (1) year from the date of installation, but not longer
than 15 months from the date of shipment from the factory, [unless a Special Warranty Period applies, as
listed below]. This warranty does not extend to any product that has been subject to misuse, neglect or
alteration after shipment from the Armstrong factory. Except as may be expressly provided in a written
agreement between Armstrong and the user, which is signed by both parties, Armstrong DOES NOT MAKE
ANY OTHER REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT
LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR ANY IMPLIED WARRANTY OF
FITNESS FOR A PARTICULAR PURPOSE.
The sole and exclusive remedy with respect to the above limited warranty or with respect to any other claim
relating to the products or to defects or any condition or use of the products supplied by Armstrong, however
caused, and whether such claim is based upon warranty, contract, negligence, strict liability, or any other
basis or theory, is limited to Armstrong’s repair or replacement of the part or product, excluding any labor or
any other cost to remove or install said part or product, or at Armstrong’s option, to repayment of the
purchase price. As a condition of enforcing any rights or remedies relating to Armstrong products, notice of
any warranty or other claim relating to the products must be given in writing to Armstrong: (i) within 30 days
of last day of the applicable warranty period, or (ii) within 30 days of the date of the manifestation of the
condition or occurrence giving rise to the claim, whichever is earlier. IN NO EVENT SHALL ARMSTRONG
BE LIABLE FOR SPECIAL, DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES,
INCLUDING, BUT NOT LIMITED TO, LOSS OF USE OR PROFITS OR INTERRUPTION OF BUSINESS.
The Limited Warranty and Remedy terms herein apply notwithstanding any contrary terms in any purchase
order or form submitted or issued by any user, purchaser, or third party and all such contrary terms shall be
deemed rejected by Armstrong.
Special Warranty Periods are as follows:
Series EHU-700 Electric Steam Humidifier, Series HC-4000 HumidiClean Humidifier and
GFH Gas Fired Humidifier with Ionic Beds:
Two (2) years after installation, but not longer than 27 months after shipment from Armstrong’s factory.
Armstrong International, Inc.
816 Maple St., P.O. Box 408, Three Rivers, MI 49093 - USA Ph: (269) 273-1415 Fax: (269) 273-9500
Parc Industriel Des Hauts-Sarts, B-4040 Herstal/Liege - Belgium Ph: (32 (42) 409090 Fax: (32) (42) 481361
Steam Traps \ Humidifiers \ Steam Coils \ Valves \ Air Vents \ Water Heaters \ Pump Traps
Bult 526-G 3/03 2M
www.armstrong-intl.com
Printed in U.S.A.
32
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