Armstrong World Industries EHU-703, EHU-701, EHU-700, EHU-704 User Manual

Installation and Maintenance

Series EHU-700 Humidifiers

Please Read And Save These Instructions

The Armstrong Series EHU-700 humidifier is an electronically controlled, non-pressurized steam-generating humidifier, with its vapor discharged into a duct of an air-handling system or through a fan package. The Armstrong Series EHU-700 consists of three models: The EHU-701, 703 and 704. The maximum capacity of the series is 240 Ibs/hr.

To allow the Series EHU-700 humidifier to function to its full capability, be certain to install it in accordance with the following Armstrong recommendations. For further assistance, please contact your local Armstrong representative for the video tape, "Armstrong Series EHU-700 Humidifiers: Installation, Operation and Maintenance".

Bulletin 527-G

DANGER

ELECTRICAL SHOCK HAZARD

HIGH VOLTAGES EXIST INSIDE THE HUMIDIFIER

To protect yourself and others from accidental shocks:

1. Keep the humidifier locked during normal operation and store the key in a safe location away from the humidifier.

2. ALWAYS DISCONNECT THE POWER SUPPLY AT THE CIRCUIT BREAKER OR SAFETY

SWITCH BEFORE OPENING ANY COVERS!

3. Before servicing the humidifier, learn where the high voltage parts are. KEEP HANDS AND METAL TOOLS AWAY FROM THESE AREAS!

Figure 2-1 Figure 2-2

TABLE OF CONTENTS

SECTION 1: PREPARATION AND INSTALLATION

WARNINGS.................................................................................................................. 2

PRE-INSTALLATION................................................................................................... 4

Check shipment................................................................................................ 4

Check local codes............................................................................................ 4

Site selection.................................................................................................... 4

INSTALLATION........................................................................................................... 6

Mounting........................................................................................................... 6

Electrical wiring................................................................................................ 6

Water supply..................................................................................................... 7

Drain connection............................................................................................... 7

Steam dispersion tube...................................................................................... 7

Control wiring.................................................................................................... 9

High limit humidistat......................................................................................... 11

Airflow switch.................................................................................................... 11

Audible alarm.................................................................................................... 12

Wiring diagram.................................................................................................. 12

SECTION 2: START-UP AND OPERATION

DISPLAY (INSTRUMENT) PANEL............................................................................... 13

START-UP PROCEDURE.............................................................................................. 14

SECTION 3: TROUBLESHOOTING AND MAINTENANCE

TROUBLESHOOTING GUIDE..................................................................................... 17

Principle of operation......................................................................................... 17

Operational guidelines....................................................................................... 18

Diagnostics......................................................................................................... 20

WATER QUALITY AND TREATMENT.......................................................................... 23

General.............................................................................................................. 23

Conductivity too low........................................................................................... 23

Conductivity too high......................................................................................... 24

MAINTENANCE............................................................................................................ 25

Parts................................................................................................................... 25

Recommended maintenance............................................................................. 29

Steam generator maintenance, general............................................................ 29

Tank removal and replacement......................................................................... 30

Chemical tank cleaning..................................................................................... 31

Fill and drain valve repair................................................................................... 33

TANK DISASSEMBLY,

ELECTRODE REPLACEMENT.................................................................................... 33

EHU-703,704..................................................................................................... 33

EHU-701, single and three phase...................................................................... 34

HUMIDISTAT DATA...................................................................................................... 36

Autocal Procedure............................................................................................. 36

Sensor Failure Protection.................................................................................. 36

High Limit Humidity Sensor .............................................................................. 38

Humidity Set Point Reset by Outside Temperature .......................................... 38

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 will arrive in two or three cartons.

One carton holds the humidifier with the steam generator installed, the control humidistat and sensing element, two short steam hoses, hose clamps, mounting plate and lag screws, and a clear drain hose. If you have ordered a duct pressure switch or a high limit stat, these too will be in the humidifier carton.

The steam dispersion tube(s) and fittings are contained in another carton ( two for the EHU 704).

Two complete sets of installation instructions have been shipped with your unit. One is for the installer's use. The second is for the owner's files.

2) CHECK LOCAL CODES

Series EHU-700 humidifiers should be installed in

accordance with ALL

applicable building, plumbing, and electrical codes.

3) SITE SELECTION

Electronic steam humidifiers must be installed in locations that allow routine inspection and accessibility for maintenance operations. See Figures 4-1 & 4-2 for access space.

Do not place electronic steam humidifers in locations where unusual instances of malfunction of the humidifier or the system might cause damage to non-repairable or un-replaceable, or priceless property.

Connection Access

2 G T

4 C

Figure 4-2. EHU-703/704

Figure 4-1. EHU-701

4" Min. Steam

enerator

ank Removal

" Side

learance

24" Front Clearance

4" Side Clearanc Both Side

5" Min. Drain

24" Side Clearance

5" Min. Drain Connection Access

The mounting surface should be a wall capable of supporting the maximum humidifier weight. The maximum operating weight is:

The location chosen should be inside with a minimum ambient temperature of 40°F. and a maximum of 100°F. The humidifier should not be mounted on hot surfaces.

The location should be close enough to the air duct so that the length of steam pipe is as short as possible. A length of 10 ft. or less is ideal; the maximum recommended length for running distribution piping is 40 feet of equivalent run. The number of piping elbows in the installation should be minimized (see Pages 7 and 8 for more information.)

The unit should have ready access to electrical service, a supply of ordinary tap water, and a sewer into which the drain line can discharge hot waste water. (Figure 5-1)

NOTE: Please contact factory for duct applications offering high static pressure (>4" WC).

Model unit

701 703

704

Water

60 Ibs. + 20 Ibs. = 83 Ibs. + 30 Ibs. =

95 Ibs. + 60 Ibs. =

Total

80 Ibs. 113 Ibs.

155 Ibs.

Figure 5-1

INSTALLATION

4) MOUNTING THE HUMIDIFIER MODEL EHU-701: Making sure the unit is level, hold it against the mounting surface and mark

the hole pattern. Attach the units to studs or other sturdy structure with the two 3/8"× 1½" lag screws provided.

MODELS EHU-703 & 704: Making sure the mounting bracket is level, attach it to studs or other

sturdy structure with the two 3/8"× 1½" lag screws provided. Hang the humidifier on the mounting bracket.

5) ELECTRICAL SERVICE WIRING

Refer to the nameplate on the unit for recommended fuse size. Table 6-1 relates the fuse size to the appropriate branch size. A complete wiring diagram shown in Figure 12-1 is located inside the door of the humidifier.

IMPORTANT: Please observe the following:

a. Make certain there is a manually operated interlocking circuit breaker or safety switch (not

furnished) in the electric service ACCESSIBLE TO AND WITHIN SIGHT OF THE HUMIDIFIER.

b. USE ONLY WIRE WITH COPPER CONDUCTORS RATED 90°C OR HIGHER

FOR HIGH VOLTAGE AND GROUNDING.

c. Pass high voltage ground lead through provided ferrite core (AN) between where it enters

the cabinet and where it connects to ground lug.

d. Ground the humidifier cabinet; a ground lug is provided in the wiring compartment.

Table 6-1. Series EHU-700 Capacities and Electrical Ratings

Nom

Recommended Output Per Hour @ Voltage Shown

Amp

Current Branch Circuit Single Phase Three Phase

Rating

Module

Wire

Circuit 120 208 240 277 208 240 346

380 415

480 600

Breaker lb kg lb kg lb kg lb kg lb kg lb kg lb kg lb kg lb kg lb kg lb kg

EHU-701 Humidifier (One Small Steam Generator)

7 CM 7 14 15 2 0.9 4 1.8 5 2.3 6 2.7 7 3.2 8 3.6 12 5.4 13 6 15 6.8 17 7.7 21 9.5 12 CM 12 14 15 4 1.8 7 3.2 8 3.6 10 4.5 12 5.4 14 6.3 21 9.5 23 10.4 25 11.3 29 13.2 36 16.3 14 CM 14 12 20 5 2.3 8 3.6 10 4.5 11 5 15 6.8 17 7.7 24 10.9 27 12.2 29 13.2 34 15.4 42 19 16 CM 16 12 20 6 2.7 10 4.5 11 5 13 6 17 7.7 19 8.6 28 12.7 30 13.6 33 15 38 17.2 — — 20 CM 20 10 25 — — 12 5.4 14 6.3 16 7.3 21 9.5 24 10.9 35 15.9 38 17.2 42 19———— 24 CM 24 10 30 — — 14 6.3 17 7.7 19 8.6 25 11.3 29 13.2 42 19———————— 32 CM 32 8 40 — — 19 8.6 22 10 26 11.8 33 15 38 17.2 —————————— 40 CM 40 8 50 — — 24 10.9 28 12.7 32 14.5 42 19————————————

EHU-703 Humidifier (One Large Steam Generator)

20 CM 20 10 25 — — 12 5.4 14 6.3 16 7.3 21 9.5 24 10.9 35 15.9 38 17.2 42 19 48 21.8 60 27.2 24 CM 24 10 30 — — 14 6.3 17 7.7 19 8.6 25 11.3 29 13.2 42 19 46 20.9 50 22.7 58 26.3 72 32.7 32 CM 32 8 40 — — 19 8.6 22 10 26 11.8 33 15 38 17.2 55 24.9 61 27.7 66 29.9 77 34.9 96 43.5 40 CM 40 8 50 — — 24 10.9 28 12.7 32 14.5 42 19 48 21.8 69 31.3 76 34.5 83 37.6 96 43.5 120 54.4 48 CM 48 6 60 — — 29 13.2 33 15 39 17.7 50 22.7 58 26.3 83 37.6 91 41.3 100 45.4 115 52.2 — —

EHU-704 Humidifier (Two Large Steam Generators)

40 CM 20 8 50 — — 24 10.9 28 12.7 32 14.5 42 19 48 21.8 69 31.3 76 34.5 83 37.6 96 43.5 120 54.4 48 CM 24 6 60 — — 29 13.2 33 15 39 17.7 50 22.7 58 26.3 83 37.6 91 41.3 100 45.4 115 52.2 144 65.3 64 CM 32 4 80 — — 39 17.7 45 20.4 51 23.1 67 30.4 77 34.9 111 50.3 122 55.3 133 60.3 154 69.8 192 87.1 80 CM 40 3 100 — — 48 21.8 56 25.4 64 29 83 37.6 96 43.5 138 62.6 152 68.9 166 75.3 192 87.1 240 108.8 96 CM 48 2 125 — — 58 26.3 67 30.4 77 34.9 100 45.4 115 52.2 166 75.3 182 82.5 199 90.2 230 104.3 — —

NOTES:1346 Volt units require 346/200 volt 4-wire system.

415 volt require 415/240 volt 4-wire system.

KW rating = humidiity output (lbs/hr) x 0.345 (for energy calculations only; not for branch circuit sizing).

6) WATER FILL SUPPLY

Connect the unit to the building water supply (25 to 125 psig pressure). Install a shut-off valve near the humidifier. Connect the water supply to the 3/8" tube compression fitting on the fill valve adaptor.

NOTE: ORDINARY (POTABLE) TAP WATER IS RECOMMENDED. IF POTABLE WATER IS NOT

AVAILABLE, CONSULT THE FACTORY (SEE "WATER QUALITY AND TREATMENT SECTION OF THIS MANUAL, PAGE 23, FOR MORE INFORMATION). DO NOT USE BRACKISH OR CONTAMINATED WATER.

7) CONNECT DRAIN

Connect to a suitable waste draining system. Use the clear drain hose provided and a 1" copper pipe (Figure 7-1), pitched 1"per foot. The drain water may be as hot as 160°F. Drain it where it will not present a hazard to personnel. An air gap to prevent backflow is required if drain water is required to be less than 140°F, use of Temp-R-Drain will be required.

8) INSTALL THE STEAM

DISPERSION TUBE NOTE: Please

contact factory for duct applications offering high static pressures (>4"WC).

a. Verify that the proper length and type of

steam dispersion tube has been selected: See Chart 7-1 for proper dispersion tube lengths. The low capacity dispersion tube (Figure 7-2) is sloped toward the generator to allow for gravity drainage. On applications where the humidifier output capacity is greater than 40 Ibs/hr, a high capacity tube with a ½"O.D. drain tube must be used (Figure 7-3). Drain tube must have minimum 6" water seal (see Fig. 8-3).

b. Select a location on the duct that provides

adequate length for vapor mixing and the shortest connection length for vapor mixing and the shortest connection length to the humidifier. Preferably the location should be 6" downstream and/or 10 feet upstream from any dampers, vanes, bends in the duct, or controllers (i.e. high limit stat). See page 10 for details. 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 air flow as dynamic air pressure will restrict steam flow.

Copper Pipe

40 lb/hr or Less

Figure 7-1

Chart 7-1. Selecting Proper Steam Dispersion Tube

Steam

Steam Disp. Duct Width

Weight

Disp. Tube Tube Length Min. Max. Model No.

in mm in mm in mm lb kg

D-1 12 304 11 279 16 406 3 1.4

D-1.5 18 457 17 432 22 559 3 1.4

D-2 24 609 23 584 34 864 4 2 D-3 36 914 35 889 46 1168 6 3 D-4 48 1219 47 1194 58 1473 8 3.6 D-5 60 1524 59 1499 70 1778 9 4 D-6 72 1829 71 1803 82 2083 10 4.5 D-7 84 2133 83 2108 94 2388 11 5 D-8 96 2438 95 2413 106 2693 12 5.5 D-9 108 2743 107 2718 118 2998 13 6

D-10 120 3048 119 3023 130 3302 14 6.4

Figure 7-2

Figure 7-3

1" I.D. Clear Hose Supplied with Unit

Fit Hose Inside 1-1/2" Pipe

1" or Larger

.00

6.00

5.25

Ø.22

4 Places

5.25

Ø1.75

Hole in Duct

For Steam Capacity

.00

3.50

1.00

6.00

5.25

R.88

R.37

Ø.22

4 Places

5.25

3.50

Hole in Duct

For Steam Capacity

Above 40 lb/hr

2.00

1.50

c. Use the template provided to cut installation

holes in the duct for the dispersion tube as in Figure 7-2 (and optional drain tube, Figure 7-3).

d. Insert the dispersion tube into the duct so

the holes face upward. 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.

e. Connect the dispersion tube to the steam generator using 1¼" (EHU-701) or 1½" (EHU-703,704)

nom. size hard copper tube (customer supplied) and the two short hoses supplied with the humidifier (Figure 8-1). Pipe size may need to be increased to 1½" or 2" when piping runs are long or back pressure in duct is high, see Figure 9-2. If piping plus duct back pressure exceeds 4" WC, please consult factory. In addition, a short length of nominal

1½" threaded black iron pipe

and a copper tube to female pipe thread adaptor must be supplied by the customer for attaching the piping to 703 or 704 tanks (Figure 8-2).

A 1½" to 1¼" reducer will be required

to connect the dispersion tube to the steam pipe of Models EHU-703/704 (Figure 8-5).

The steam pipe must be free of kinks and sags to allow for gravity drainage of condensate. (Provide pitch of 1" per foot towards the unit.) Pipe supports may be required to accomplish this. Insulate the copper tube to minimize condensation.

The preferred installation of the dispersion tube is above the humidifier with a maximum piping run of 20 feet or less (Figure 8-3).

Figure 8-4 shows the correct installation when:

1) You cannot achieve a 1" per foot reverse slope of the piping.

2) Piping runs range from 20 to the maximum of 40 feet of equivalent run.

3) Elbows or vertical risers must be placed in the piping.

4) The steam dispersion tube MUST BE

below the humidifier. For this installation use a 1¼" copper tee for the drain connection of an EHU-701 or a 1½" copper tee for EHU-703 or 704 (Figure 8-5).

EHU-701

n d

1-1/2" to 1-1/4" Copper R

Figure 8-1. EHU 701

Figure 8-2. EHU 703/704

Figure 8-3

Figure 8-4

Figure 8-5

1-1/4" Copper Tube

1-1/2" I.D. Hose

EHU-701 Steam Generator To

1-1/2" Copper Tube

Copper Tube Female Pipe Adapt

1-1/2" Pipe

Hose Clamp

2" I.D. Hose

team

Outlet

Duct Above Outlet

6" Water Seal

Holes in dispersio tube to be installe in "UP" position

Floor

Drain

educer if Needed

1-1/2" I.D. Hose

1/2" PVC Tubing

1/2" O.D. Copper T ubing

CONTROL WIRING

NOTE: Wiring to the low-voltage controls should not run in the same conduits as the power supply

wiring because faulty signals could result. The use of either a metal conduit or shielded wire is required for all the control and / or safety wiring. When using metal conduit, the conduit must extend the entire length of the wire, and the conduit must be grounded at the humidifier cabinet. If the conduit does not extend the entire length of the control wire, the wiring must be shielded and the following guidelines must be used:

1. The wire shields and all unused conductors must be grounded externally to the humidifier cabinet.

2. Ensure a good connection between the shields / conductors and the metal bar of the humidifier cabinet.

Additionally, a supplied ferrite core must be installed around the control wiring between where the wire enters the humidifier cabinet and the low voltage terminal block.

9) CONTROL HUMIDISTAT

The Series EHU-700 is capable of accepting controls signals with the following characteristics:

a. 0-10 Vdc Humidistat

(Part No. A18609 and A18610) (H200 or H270 series)

b. 1.9-3.9 Vdc Humidistat

(Part No. C1471 or C1472)

c. 4-20mA, 250 Ω input impedance.

d. 0-10 Vdc, 50 kΩ input impedance.

e. 0-5 Vdc.

f. 0-135 ohms.

g. on/off

To adapt the EHU-700 to these different types of control humidistats, jumper BJ4 and BJ5 on the printed circuit board (Figure 9-1) must be manually changed and the humidistat must be wired to the appropriate connections of terminals 1, 2 & 17. Refer to Figure 9-1 or the sticker on the inside of the cabinet for proper jumper locations.

(

Pressure Loss in Copper Pipe

Figure 9-1

Figure 9-2

Chart 9-1

(75 mm)

5-1/2"

140 mm)

n. WC

2 1

(40' Equivalent Run)

#/Hr. Steam

1-1/4"

1-1/2"

100

110

Feet of equivalent copper pipe for copper pipe fittings

Fitting 1-1/4 1-1/2 2 45° Elbow 1.0 2.2 2.8 90° Elbow 2.5 4.3 5.5 90° Long Elbow 1.5 2.7 3.5 Tee 5.0 9 12

Wall Mounted Control Humidistat:

Wall-mounted humidistats 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 following criteria:

• 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.

• Locations near coffee machines, computer blower outlets, doors to other rooms, or windows that can be opened are not suitable.

Figure 10-1

Modulating

High Limit

Sensor

Safety

High Limit

Humidistat

(optional)

6 - 10 Ft.

Air Flow Switch

Outdoor Temperatur Sensor

Outside A

Humidifier Location

Humidifier

onnections

Main Humidity Sensor

Duct Mounted Control Humidistat:

Duct-mounted control humidistats are also available for installation where sensing and control of return air or exhaust air ducts is preferable. (Figure 10-1)

Please refer to manufacturer's recommendations for further information on the location, mounting, and operation of the various control humidistats.

10) HIGH LIMIT DUCT HUMIDISTAT

Remove the jumpers tab from terminals 10 & 14 and wire the high limit stat between these terminals. Refer to Figure 10-1 and Figure 11-1 (the overall wiring diagram) for more information. A duct mounted high limit humidistat is recommended to prevent over-saturation of the duct air. Use an on-off controller that opens on fault (high humidity). Humidistat should be set for a maximum of 90% RH. Alternately, a modulation high limit humidistat may be used on applications such as variable air volume (VAV). Locate the high limit humidistat approximately 10' (3m) downstream of the dispersion manifold. If 10' (3m) is not available, consult the factory.

11) AIRFLOW SWITCH

An airflow switch is recommended to deactivate the humidifier when there is insufficient air flow in a duct system. A duct pressure switch is preferred as an airflow sensor. The pressure switch should open on insufficient airflow (opens on fault). Airflow switch should be mounted in supply air duct upstream of humidifier dispersion. Remove the jumper tabs between terminals 9 & 15 and wire the airflow sensor between these terminals. See Figure 11-1 and Figure 12-1 (the overall wiring diagram) for more information. Complete installation and wiring instructions are contained in the duct pressure switch package.

NOTE: LIMIT SWITCHES (HIGH LIMIT AND AIRFLOW SWITCHES) OPEN ON FAULT.

On-Off Humidistat

Figure 11-1

1.9 - 3.9 Vdc

oltage Source

Ground

Set BJ4 Stat Input Selector to 1.9 - 3.9 Vdc

Stat In

N/C

Set BJ5 Voltage Source to 12 Vac

Black White

Green

Part No.

C1471

C1472

Voltage Source

4-20 mA & 0-10 Vdc Setting*

oltage Source

*See Figure 10-1 for Armstrong 0-10 Vdc Humidistat Connections

Ground

Stat In

N/C

Set BJ4 Stat Input Selector to

0-10 Vdc or 4-20 mA

Voltage Source

Switch Opens on RH Rise

Ground

Stat In

N/C

Set BJ4 Stat Input Selector to On/Off

Set BJ5 Voltage Source to +5 Vdc

Brown

Orange

Part No.

A8581

A8581A

0-135 Ω Ohm Potentiometer

Part No.

Ground

Stat In

N/C

Set BJ4 Stat Input Selector to 0-135 Ohm

Set BJ5 Voltage Source to +5 Vdc

A6707A

A18611

Humidity

Increase

12) AUDIBLE ALARM

There is an external alarm circuit provided. When an alarm condition is detected in the diagnostic routines, a relay contact closes allowing activation of an external Class II device connected between terminals 27 & 28. This circuit is rated to 1 amp.

Figure 12-1

Low-Voltage Low-Energy

Controls

Main Control Humidistat

High Limit* Humidistat

Air Flow* Switch

N.O. Alarm Relay

*Must be closed to run

24 VAC

Fill Valve

24 VAC

Drain Valve A

Panel Switches

Tank

Drain

On/Off

Micro Controller

Printed Circuit

Board

LED

Display

Mode

Select

Three-Digit

Numerical Display

High Water

Switch A

Current

Transformer

24 VAC

Contactor

Steam

Generator A

Side 1

24 V Secondary

Power Transformer

Side 2

High Voltage

Terminals

INSTRUMENT PANEL

The Mode select button is depressed for

approximately ½ second to switch both the

"display mode selected" indicator and the 3

MODE BUTTON, digit display between: INDICATOR, -DEMAND- % of humidistat control range. and DISPLAY -CURRENT- actual current in amps.

-% POWER- ratio of current draw to the

nominal rating of the unit.

-DIAGNOSTIC MODE- readout of diagnostic

codes.

Leaving the display in the diagnostic mode for 10 seconds initiates the input/output diagnostic routine (see Diagnostics pg. 20).

The 3 digit display also exhibits a diagnostic code in the event that the unit has shut down automatically.

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.

HIGH WATER LIGHTIndicates that the water level in the generator has risen to the high

water level.

TANK OFF LIGHT Indicates when power to the generator has been interrupted (tank

contactor open).

TANK ON/OFF Depressing the tank on/off button for ½ second will open the tank

contactor. The tank off light and the diagnostic light will be on and the display will show the message CO8. The unit will stay in this mode until the button is pressed again.

MANUAL DRAIN Depressing the manual drain button for ½ second will open the drain BUTTON valve. The tank will continue to drain until the button is pressed again.

DEMAND CURRENT % POWER DIAGNOSTIC

FILL DRAIN HIGH WATER TANK OFF

MODE SELECT TANK ON/OFF DRAIN ON/OFF

START-UP PROCEDURE FOR ARMSTRONG SERIES EHU-700 HUMIDIFIERS

The following steps should be performed on all newly installed Series EHU-700 Humidifiers to ensure that the humidifier and the entire humidification system functions correctly.

BEFORE TURNING ON THE POWER

Figure 14-1

1) Examine the wiring and the components in the electrical compartment.

2) Check for any loose wires or quickconnect terminals that may have been pulled loose.

3) Using a screwdriver, TIGHTEN ALL SCREW TERMINALS on the power supply terminal block, ground lug, and contactor (Figure 14-1).

Make sure all steam generator tank connections are tight. Remember, a loose joint is a HOT joint and could be a fire hazard!

4) Locate the low voltage terminal block (Figure 14-1).

Verify that an airflow switch is connected between terminals 9 and 15 or that there is a jumper installed. If an airflow switch is installed, ensure that there is airflow.

Verify that a high limit stat is connected between terminals 10 and 14 or that a jumper is installed.

5) Turn on the water supply - Check for leaks.

TURN ON POWER AT THE CIRCUIT BREAKER

6) The following should happen:

a) The Demand Mode and Tank Off lights will be illuminated. The stat demand will be

displayed.

b) If the stat demand displayed is greater than 35%, the Tank Off light will go out and a few

seconds later the Fill Light will go on. The unit will begin to fill.

Current Transformers

Contactors

Power Supply Terminal Block

Low Voltage Terminal Block

If the stat demand display is greater than 35% and the unit does not begin filling, press the mode select button three times and the diagnostic mode indicator will light. Note the diagnostic message and refer to the diagnostics information in the troubleshooting section of this manual (page 20).

c) If the stat demand is less than 35%, force a 100% humidity demand by setting

humidistat dial to 95% RH. Alternately, a 100% demand can be simulated by setting BJ4 jumper to position 3-4 (on/off), set BJ5 to position 1+2 (5 VDC) and installing a jumper between terminals 17+1 of the low voltage terminal block inside humidifier.

7) Let the unit continue to fill and allow the water to boil.

a) If the water level reaches within 4" of the Steam Generator Tank top, the High Water Float

Switch will block the fill and illuminate the High Water light momentarily. This is normal on relatively pure water. Pressing the mode button to check the diagnostic display will result in an indication of C01. To complete the start-up testing in this instance, push the Drain switch to drain 1/2 of the tank. Next, turn off power at the breaker or safety switch and add one pinch (1/2 teaspoon) of Epsom salts to the Fill Cup (See Part #25 on Page 28). This should allow the water to boil by increasing the water's conductivity. (See "Water Quality and Treatment for EHU Humidifiers" in the troubleshooting section on page 23.) Reapply power to energize the humidifier.

8) On typical beginning fill, after the fill stops, press the mode button until percentage of maximum power is indicated. The numerical display should read a few points above 40%.

9) Press the Drain switch. Verify that the unit is draining freely.

10) Inspect the steam outlet piping. Verify that there are no un-trapped low spots. Also verify that the

piping is insulated and properly sloped (See Step 8 on Page 7).

11) If the Dispersion Tube is equipped with a drain fitting, verify that is working.

12) Verify operation of high limit humidistat and or air proving switch, if used.

a) If high limit is used, turn dial to minimum setting, 10%. Display of unit should read CO4 and

unit should stop steam production. Turn humidistat dial to maximum of 90% and unit should return to normal operation.

b) If pressure switch is being used, verify airflow condition in duct or air handler.

- If air flow is present, unit should be in normal operation. Disconnect wire from terminal 15 at humidifier. Display should show CO3, and unit will stop operation. Reconnect wire to terminal 15, and unit should return to normal operation.

- If Air Flow is not present in Duct or Air Handler, unit should be sitting IDLE and Display should be showing CO3. Turn fan on and verify duct or Air handler now has airflow present. Unit should return to normal operation.

13) While humidification is being demanded, turn humidistat dial down to near zero. The following

should happen:

a) The stat demand reading will decrease to zero. b) The unit will shut down, lighting the Tank Off light.

14) Turn humidistat dial to the desired value.

15) Verify that all of the input/output circuits are functioning properly by entering the input/output diagnostics mode. Press the mode button until the diagnostics indicator lights and wait ten seconds. The unit will do a complete self-diagnostic check. See CO in the diagnostics section of this manual (page 20) for more information.

16) Turn power off, if humidification is not needed.

17) Close and lock the doors, and store the key away from the unit.

TROUBLESHOOTING GUIDE

CAUTION!: Disconnect the electric power supply at the circuit breaker or switch whenever the unit is to be inspected or serviced. DO NOT USE THE TANK ON/OFF SWITCH ON THE HUMIDIFIER BECAUSE THIS SWITCH DISCONNECTS THE STEAM GENERATOR TANK ONLY.

PRINCIPLE OF OPERA

TION - AN OVERVIEW

The Armstrong Series EHU-700 electronic steam humidifier Figure 17-1 converts ordinary tap water to steam and distributes it within the air being humidified to bring the relative humidity up to the desired level.

The humidity demand is sensed by the humidistat. A microcontroller converts this demand signal into an amperage requirement. If humidistat demand is above 35%, the internal power contactor closes, applying voltage to the electrodes, and the fill valve opens to begin filling the tank. 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 (Figure 17-1).

As the water level rises (Figure 17-2) increased electrical

Figure 17-2

current flows through the water, producing more steam. This increase will continue until the desired current level (i.e. required steam output) is reached. At this point, the fill valves will cycle off and on to maintain the desired amperage ±5%. The desired current level is a function of the nominal current rating, humidistat demand, and the automatic capacity adjustment feature.

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. This allows the amperage to decrease, thereby reducing the steam flow. The fill valve can then cycle at the lower steam output (current) requirement. When the humidistat demand signal drops below a minimum

Figure 17-3

25% demand, the contactor is de-energized, and steam output stops (Figure 17-3).

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 by opening the tank contactor if there is too much humidity or insufficient airflow within the duct.

Current Sensor

Controlling Humidistat

High-Limit Humidistat

Fan Interlock

Current Sensor

Controlling Humidistat

High-Limit

Humidistat

Fan Interlock

Current Sensor

Controlling Humidistat

High-Limit

Humidistat

Fan Interlock

External

Disconnect

Line

Fill Valve

Controller

External

Disconnect

Line

Fill Valve

Controller

External

Disconnect

Line

Fill Valve

Controller

Internal

Power

Contactor

Overflow

Line

Internal

Power

Contactor

Overflow

Line

Internal

Power

Contactor

Overflow

Line

Fill Cup

Distribution

High-Water

Float Switch

Drain Valve

Distribution

High-Water

Float Switch

Drain Valve

Distribution

High-Water

Float Switch

Drain Valve

Tube

A high-water float switch prevents water carry-over into the duct due to an excessive water level in the tank. When the high water limit is reached the HIGH WATER light comes on and the fill valve is blocked until some water is boiled away and the water level drops. This is common during startup. If the high water light comes on and the water level is in the lower half of the steam generator, contact the factory for assistance. This is due to high static pressure. Installation of fill cup extension kit could be required.

If an overcurrent situation is detected, the overcurrent protection circuit will drain water from the tank to reduce current flow. If the overcurrent persists, the contactor will be de-energized to stop all current flow.

The Series EHU-700 patented automatic capacity adjustment feature eliminates manual adjustment and improves humidity control. This feature automatically adjusts maximum output up or down depending on the humidity demand history. When the unit is first turned on the maximum output is 40%. If the demand stays high, the unit automatically steps up the maximum output and will reach 100% maximum output after one hour. For test purposes, or for special operating situations, this feature can be easily over-ridden by changing the position of jumper BJ1 on the printed circuit board from pins 1 and 2 to pins 2 and 3.

An automatic drain cycle blows down mineral-laden water to increase steam generator life and reduce maintenance requirements. The frequency and duration of the drain cycle will vary with supply water conductivity, steam output, and humidistat demand history. When it is initiated automatically, the drain valve cycle occurs at the beginning of a fill cycle. The incoming cold water tempers the drain water to less than 160ºF after 72 hours of no demand, the unit will initiate an "End-of-Season" drain to remove stagnant water.

OPERA

TIONAL GUIDELINES

This section describes the conditions and indications you should expect to find in a normally operating humidifier.

Tank Contactor Operation:

The microcontroller will de-energize the contactor, turning off the current to the electrodes if ANY of

the following occur:

1. The control humidistat demand signal is less tan 25%.

2. The fan interlock circuit is open.

3. The high limit humidistat circuit is open.

4. The tank current is greater than the over-current limit.

Conversely, the microcontroller will energize the contactor, turning on the current to the electrodes,

only if ALL of the following occur:

1. The control humidistat demand signal is greater than 35%.

2. The fan interlock circuit is closed.

3. The high limit humidistat circuit is closed.

There is a time delay of fifteen seconds in the contactor operating circuitry to prevent it from cycling too rapidly after it has been turned off.

Monitoring Stat Demand:

Indicates the demand for humidity in relationship to the control range of the humidistat. 0% indicates that the humidity requirement has been exceeded. 100% indicates that the humidistat is calling for full humidifier output. In general, a reading of around 50% indicates that the set point has been met.

Monitoring Current:

While the unit is filling, the current should increase. As the current approaches the maximum rating of the unit, it increases more slowly, especially in higher capacity units. With the tank on, and the fill and drain circuits idle, the current should fall slowly. When the unit is draining, the current should decrease at a moderate rate.

Monitoring % Power:

The percentage power equates to the percentage of maximum steam output. The percentage power reading will increase and decrease proportionally to the current draw. Overcurrent protection circuitry starts initiating drain cycles as the % power reading approaches 110%. The overcurrent failure routine is initiated at about 120%.

Automatic Drain Operation:

The microcontroller will energize the drain valve at the beginning of the fill cycle to reduce the conductivity and mineral build-up in the tank. It will vary in drain duration to adjust for changes in water quality, demand history, and steam output.

Manual Drain Mode:

If the manual drain button is pushed while the tank circuit is energized, the fill valve will also open to temper the drain water. If the tank is off, only the drain valve will open.

EHU-700 DIAGNOSTICS

THE Series EHU-700 has built in diagnostics to detect system problems early, before they become severe. If possible, the diagnostic routine performs corrective measures. If necessary, the unit is shutdown and a dry contact is closed to enable a remote alarm.

The diagnostic messages that result in the unit being shutdown are displayed automatically. The other messages are displayed when the diagnostic display mode is selected with the mode switch. If the display mode selection is left in the diagnostic mode for 10 seconds, the Input/Output circuit diagnostic check will begin.

DIAGNOSTIC DISPLAY MESSAGES

C00 = NORMAL OPERATION C01 = HIGH WATER C02 = TANK NEEDS CLEANING* C03 = INTERLOCK CIRCUIT C04 = HIGH-LIMIT CIRCUIT C05 = DRAIN SYSTEM FAILURE* C06 = FILL SYSTEM FAILURE* C07 = OVERCURRENT FAILURE* C08 = MANUAL TANK SHUT-OFF C09 = I/O DIAGNOSTICS

* Automatic shutdown and Alarm contact closure.

C00: NORMAL OPERATION

C01: HIGH WATER:

A high-water float switch prevents water carry-over into the duct due to too high a water level in the tank. When the high water limit is reached the HIGH WATER 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. The diagnostic display mode will indicate C01.

NOTE: the high water light goes off as soon as the high water condition is cleared but the

operation on the fill valve does not resume until after a fifteen second delay period. If C01 is displayed and the water level is in the lower half of the steam generator, high static pressure exists, contact the factory for assistance.

C02: TANK NEEDS CLEANING:

If the HIGH WATER lights is on continuously during normal service (i.e. after initial startup) and the current is not increasing, the tank probably needs cleaning (refer to the maintenance section of this manual). If this condition persists without being serviced, the display panel will display diagnostic message C02. The unit will shutdown and the dry contact will close to activate the remote alarm. NOTE: False C02 messages may occur if incoming water is very pure (< 100 μMhos/cm²). Please consult factory.

C03: INTERLOCK CIRCUIT:

The fan interlock circuit may be a sail switch or (preferably) a duct pressure switch. When air flow in the duct is not present, the interlock circuit should open and the microcontroller will de-energize the contactor. The diagnostic mode will display the message C03 and the fill solenoid is blocked.

C04: HIGH LIMIT CIRCUIT:

When the humidity in the duct reaches the high limit stat set-point, the circuit will open and the microcontroller will de-energize the contactor. The diagnostic mode will display the message C04 and the fill solenoid is blocked.

C05: DRAIN SYSTEM FAILURE:

This routine checks for a failure to reduce current if the drain valve is energized for more than five seconds. If the actual current does not decrease when the microcontroller demands a drain cycle, the unit will go into a diagnostic routine. This routine will try twice to correct the drain system failure by cycling the drain valve rapidly. If the failure is not corrected, the unit will shut down. The tank off indicator will light, the numerical display will show C05 (the drain valve failure message), and the dry contact will close to activate the remote alarm.

Drain system failure can be due to a plugged drain valve, drain valve solenoid failure, scale

buildup in the tank, or drain piping problems. Refer to the maintenance section of this

manual for resolution of these problems.

C06: FILL SYSTEM FAILURE:

After start-up, if the fill valve is on and has been on for more than four minutes, the diagnostic routine will check the fill valve operation. If the actual amp signal is less than the current when the fill valve was opened, the unit will go into a diagnostic routine. If the problem cannot be corrected, a fill system failure will be triggered and the unit shut down. The three digit display will show C06 to indicate this condition, and the dry contact will close to activate the remote alarm.

Fill system failure can be due to excessive or insufficient inlet water pressure, a failed fill valve

solenoid, a plugged fill valve failed open, or a backflow preventer. Refer to the maintenance

section of this manual for resolution of these problems.

C07: OVERCURRENT FAILURE:

The overcurrent limit (OCL) is 20% above the nominal amp rating of the unit. When the actual current reaches the OCL, the microcontroller will de-energize the contactor and energize the drain valve for 15 seconds. Then the contactor will be re-energized to see if the drain valve has corrected the overcurrent condition. This procedure is repeated 5 times.

If the overcurrent still exists, an overcurrent failure indication of C07 is displayed, the unit is shut down, and the dry contact will close to activate the remote alarm. The unit will have to be manually reset and the overcurrent condition addressed by the maintenance personnel.

An overcurrent failure can result from the cold startup of a tank that was previously running at a high load, resulting in the tank water becoming too conductive for start-up. If this is suspected, manually drain the tank for 15-30 seconds, then try to restart the system. If the overcurrent failure repeats, the drain system could be partially plugged, or the tank may be in need of

cleaning. Refer to the maintenance section of this manual for resolutions to these

problems.

C08: MANUAL TANK SHUT-OFF:

The tank on/off button will de-energize the tank contactor. The tank off light and the diagnostics indicator will be on and the display will show the message C08. The unit will stay in this condition until the button is pressed again. In the tank off mode, the manual drain button is still active, but the mode select button is not.

C09: I/O DIAGNOSTICS

If the display mode selection is left in the diagnostic mode for 10 seconds, the Input/Output circuit diagnostic check will begin. The display will show the message C09, the tank will be off, and the diagnostics mode light will remain on.

Output Circuits: The diagnostics will first check all the output circuits: fill valve, drain valve,

and tank contactor to make sure they are working. When a light comes on, you will hear the corresponding valve or contactor circuit energize for about 2 seconds. Each circuit is checked twice before proceeding to the next circuit.

Input Circuits: Next the microcontroller checks the status of all input circuits, beginning with

the control stat. the 3 digit display will show 0% Demand, then the actual stat demand. It will do this twice. The input diagnostics continues by checking the fan interlock switch, high limit duct humidistat, and high water switch. The display will now show C09 followed by any additional messages that indicate problems with the input circuits.

When the I/O diagnostic check is finished, the demand mode light will be on, the display will show the control stat demand and the unit will return to normal operation. The complete I/O diagnostic check lasts less than 2 minutes.

WATER QUALITY AND TREATMENT FOR EHU SERIES HUMIDIFIERS

GENERAL

Series EHU 700 electronic humidifiers use ordinary tap water in their operation. The quality of this water affects both the operation and the maintenance of the humidifier.

How the EHU works:

The EHU is an electrode boiler. When no water is present, the electrodes are separated by air, an insulator, so no current flows. When tap water contacts the electrodes it conducts current between the electrodes, heating the water.

How much current passes between the electrodes is dependent on the conductivity of the water, which is measured in micromhos/cm (μMhos/cm). EHUs can operate effectively with water conductivity in the range of 50 (low) to 800 (high) μMhos. For conductivity greater than 800 μMhos, please consult factory. The optimum incoming water conductivity level is 200-400 μMhos/cm. the greater the conductivity of the water, the lower its level will be in the tank in order to draw a given current. In general, the EHU700 Series will adjust its drain cycle to maintain the water level around 1/3-1/2 full in the tank.

What affects conductivity?

The minerals (mainly calcium) dissolved in the water. Pure water is NOT conductive and can't be used

exclusively in an EHU without special procedures. This includes distilled, de-ionized and reverse osmosis diffusion treated water. Most tap water is conductive however, so it will work in an EHU. If tap water is not available, consult with the factory.

How does this affect maintenance?

Figure 23-1. Tank filled with mineral buildup.

Generally, the more conductive the water is, the more minerals there are dissolved or suspended in it. As the water is boiled away these minerals can be left as a deposit on the electrodes, tank, and fittings. Any deposits that build up can block valves, diminish the internal volume of the tank, and form an insulating barrier on the electrodes (Figure 23-1).

The EHU automatic drain cycle:

All Series EHU humidifiers have a built in blow down circuit to intermittently purge excess mineral accumulations from the water. The drain cycle should automatically adjust for variations in water quality. Eventually, however, minerals will accumulate in the steam generator, and have to be removed (see tank cleaning in the maintenance section of this manual).

Water treatment guidelines for the EHU:

Generally, the EHU will work with any potable water source. If you are experiencing problems with your installation, however, the following suggestions may be helpful in identifying and rectifying your difficulty.

WHEN W

ATER CONDUCTIVITY IS TOO LOW

Indicators:

-Unable to reach humidity set point in space.

-High water level in tank

-Low current draw and low % power reading even though the stat demand remains at 100%.

-Consistent drain cycles of two seconds or less.

Results:

-Excessive time needed to reach set point during star-up.

-Poor humidity control.

Remedy:

-Add 1/2 teaspoon of Epsom salts to the fill cup. After start-up the automatic drain program should maintain the unit at full capacity.

-If problem persists, contact the factory.

WHEN W

ATER CONDUCTIVITY IS TOO HIGH

Indicators:

-Water level just touching tip of electrodes.

-Arcing and foaming in the tank.

-Frequent drain cycles (every time the fill valve opens) that last up to 10 seconds.

Results:

-Tank frequently needs cleaning.

-Poor control because of excessively low water level.

-Electrode destruction.

Remedies:

-If you have pure water available such as: de-ionized water, Reverse Osmosis diffusion water, or distilled water, they can be blended with tap water to reduce the total mineral content. Pure

water alone is not conductive enough to pull current. The water is too pure when the "Tank

Full" light comes on excessively. Consult a water purification equipment vendor for the proper blending equipment or the Armstrong factory for more information regarding use of purified water. The blended water conductivity should be in the 200-400 μMhos/cm range.

-Softened water is not recommended for use with the Series EHU-700 Humidifiers. Water softeners replace the calcium ions in the water with sodium ions. As softened water boils, the sodium ions stay in solution causing the conductivity of the water in the tank to increase rapidly.

CAUTION: Soft water may increase the tank's water conductivity and does not allow a protective coating to form on electrodes. Also, as salts stay in solution more drainage will be needed to maintain correct water conductivity in the tank. Please consult factory for softened water analysis, if softened water source is available, before proceeding. Expect to replace electrodes more frequently. Discontinue service if continuous arcing or foaming occurs in the tank.

See Drawings on Page 28

EHU-701, -703, -704 Series

)

Electronic Steam Humidifier

Repair Parts

Steam Generators Complete

Item Part No. Description Used On

*1A D4417

*1B D4418

*2A D4415 3 Ph Low Voltage (208, 240, 277 volts) 701

*2B D4416 3 Ph High Voltage w/Barrier (380, 480, 600 volts) 701

3A D262A 3 Ph/1 Ph Low Voltage (120, 208, 240, 277 volts) 703,704

3B D262 3 Ph Hi

Note:

A replacement

enerator comes with a spare drain adaptor "O" Ring.

1 Ph Low Voltage 120,208,240,277 Volts

1 Ph High Voltage w/Barrier 380,480,600 Volts

h Voltage w/Barrier (380, 480, 600 volts

Steam Generator Parts

Item Part No. Description Used On

† *4A D4422 Tank Assembly Less Electrodes - 1 Phase 701

† *4B D4423 Tank Assembly Less Electrodes - 3 Phase 701

† 6 D263 Steam Generator Bottom Half-Less Drain Screen 703,704

† 6 B3968 Steam Generator Top Half- Holes Drilled 703,704

*7A B3038

*7B A10077 Electrode Replacement Assembly 3 Ph 701

8 A9745

*9A A9742 Drain Screen for Low Voltage (120, 208, 240, 277) 701

*9B B2413D Drain Screen/Barrier Assembly For High Voltage 1 Ph 701

*9C C1965 Drain Screen/Barrier Assembly For High Voltage 3 Ph 701

10 C2053 Drain Screen 703,704

11 A9746 Tank Barrier Assembly 703,704

12A A21374 O-Ring for Steam Generator 701

12B A21375 O-Ring for Steam Generator 703,704

*13 C1839 V Band Tank Clamp 701

14 B2822 Tank Retainer Clip 703,704

*Item Not Shown. † These parts are furnished as a convenience to our customers. Part dimensions may change in service. Armstrong cannot guarantee that new parts will fit your used parts.

Electrode Replacement Assembly 1 Ph High & Low Voltage

Electrode Replacement Set (Includes 6 ea. electrodes, O-Rings, 1/4" Nut & 1/2" Nut) 1 Ph/3 Ph

701

703,704

701

703,704

Valves and Mechanical Parts

See Drawings on Page 28

Item Part No. Description Used On

15 B2717 Drain Valve Assembly w/ Hose & (2) Clamps 701,703,704

16A B2582A-1 Float Switch Assembly 701,703,704

16B B2582A-2 Float Switch Assembly (Far Tank) 704

17A B4482 Fill Valve w/Flow Washer & Straight 3/8" Compression Fitting 701

17B B4480 Fill Valve w/Flow Washer & 90 Degree 3/8" Compression Fitting 703

17C B4481 Fill Valve Assembly Less Flow Washer 704

18A A8608 O-Ring for Tank Drain Adapter 701

18B A9617 O-Ring for Tank Drain Adapter 703,704

19A C2042 Tank Drain Adapter Less O-Ring 701

19B C2078 Tank Drain Adapter Less O-Ring 703, 704

20 D248 Drain Cup 701,703,704

21 A9571 Screw, Drain Cup #10-32 (2" Long) 701,703,704

22 B2859 Gasket, Drain Cup 701,703,704

23 C1838A Fill Cup 701,703,704

*24 B2929 Mounting Bracket, Fill Cup 703,704

25 A9016A-12 Tube, Fill Valve to Fill Cup 27-1/2" x 3/8" 701,703

*26 A9016-2 Tube, Fill Valve to Fill Cup Tee, 1-1/2" x 3/8" (Reinforced) 704

*27 A9016A-9 Tube, Fill Cup Tee To Cup #1, 21" x 3/8" 704

*28 A9016A-13 Tube, Fill Cup Tee To Cup #2, 38" x 3/8" 704

29A A8567-18 Tube, Fill Cup Overflow 19" x 5/8" 701

29B A8567-17 Tube, Fill Cup Overflow 31" x 5/8" 703,704

30A A8567-19 Tube, Fill Cup to Tee, 9-1/2" x 5/8" 701

30B A8567-11 Tube, Fill Cup to Tee, 14" x 5/8" 703,704

31A A9016A-8 Tube, Tee to Float Switch, 10-1/2" x 3/8" 701

31B A9016A-2 Tube, Tee to Float Switch, 17" x 3/8" 703,704

32A A8567-19 Tube, Tee to Adapter, 9-1/2" x 5/8" 701

32B A8567-16 Tube, Tee to Adapter, 12-1/4" x 5/8" 703,704

33 A8567-10 Tube, Adapter to Drain Valve, 1-3/4" x 5/8" 701,703,704

34 A9620-1 Tube, Tank/Cabinet Drain, 18" x 1" 701,703,704

*35 B2740 Flow Control Tee (Fill Cup Tee) 704 *36 B2578 Float Switch Chamber Bracket 701 *37 A9472 Fill Tubing Tee 701,703,704

*38 B2250 Steam Hose, ID 1-1/2" x 9-5/8" 701,703,704

*39 B2851 Steam Hose, ID 2" x 12" 703,704

40A B2716-11 3/8" Tube Flat Hose Clamp used at Float Switch/Fill Valve 701,703,704

40B B2716-15 3/8" Tube Flat Hose Clamp used at Fill Tee/Fill Cup 701,703,704

*41 B2716-18 5/8" Tube Flat Hose Clamp 701,703,704

42 B2911-8 Drain Valve Hose Clamp 701,703,704

*43 A8433-5 1-1/2" Steam Hose Clamp 701,703,704

*44 A8433-10 2" Steam Hose Clamp 703,704

*45 B2911-6 7/8" Fill Cup Tee Hose Clamp 704

*63 A9472 Pipe Tee 5/8" x 5/8" x 3/8" 703,704

* Item Not Shown

703,704

Electrical Parts

See Drawings on Page 28

Item Part No. Description Used On

46 C2059 Display PC Board 701,703,704

47A A22925 Control PC Board

47B A22926 Control PC Board

48A B2895-7 CM-7 Current Module 701,703,704

48B B2895-12 CM-12 Current Module 701,703,704

48C B2895-14 CM-14 Current Module 701,703,704

48D B2895-16 CM-16 Current Module 701,703,704

48E B2895-20 CM-20 Current Module 701,703,704

48F B2895-24 CM-24 Current Module 701,703,704

48G B2895-32 CM-32 Current Module 701,703,704

48H B2895-40 CM-40Current Module 701,703,704

B2895-48 CM-48 Current Module 701,703,704

49 B1992B Current Transformer 701,703,704

50 B2721 Elec Contactor 50 Amp 701,703,704

51 A10094 Fuse, 3 Amp, Set of 2 701,703,704

52A C1833 Power Transformer (120v) 701,703,704

52B C1833F Power Transformer (208v) 701,703,704

52C C1833G Power Transformer (240v) 701,703,704

52D C1833C Power Transformer (277v) 701,703,704

52E C1833H-1 Power Transformer (346v) 701,703,704

52F C1833D Power Transformer (380v) 701,703,704

52G C1833H-2 Power Transformer (415v) 701,703,704

52H C1833B Power Transformer (480v) 701,703,704

53 B2857 Cable Assy-Hex Display 701,703,704

54 B2856 Cable Assy-LED Display 701,703,704

55A D348 Wire Harness 701

55B D296 Wire Harness 703,704

56A B2419 Tank Power Lead w/Terminal 19-1/2" 701

56B B2853-13 Tank Power Lead w/Terminal 36" 703,704

56C B2853-14 Tank Power Lead w/Terminal 50" 704

57A B2334-11 Contactor Power Lead 12-1/2" 701

57B B2854-1 Contactor Power Lead 5-1/2" 703,704

*58A B2925-1 Tank Jumper Lead 10" 1 Ph 703,704

58B B2925-2 Tank Jumper Lead 14-1/2" 3 Ph 703,704

*59 B2718-1 Wire Ext. for Contactor #2 704

*60 B2718-3 Wire Ext. for Drain Valve #2 704

61 A8649 Fuse Block 701,703,704

62 B2414-3 Quick Disconnect 3 Terminal Block 701,703,704

C1833A Power Transformer (600v) 701,703,704

Less

Current Module 701

Less

Current Module 703,704

*Item Not Shown

Figure 28-1. EHU-700 Parts List

Figure 28-2. EHU-700 Steam Generator Repair Parts List

21 34

MAINTENANCE

RECOMMENDED MAINTENANCE SCHEDULE

1 TO 2 DAYS AFTER 1) Check unit operation. START UP 2) Look in drain pan for leaks.

3) Check steam piping for leaks.

4) Observe duct low points for signs of poor humidity distribution.

5) Be sure unit is draining freely by pushing the manual drain button (the manual tank off button should not be depressed).

1 MONTH TO 1 YEAR 1) Repeat the 5 steps outlined above.

2) Clean, repair, or replace steam generator.

STEAM GENERA

TOR MAINTENANCE

General:

The steam generator is basically the only part of the EHU that requires regular maintenance. This maintenance may include cleaning or replacing the tank itself or the electrodes. We recommend substituting a spare generator in order to minimize downtime and labor requirements. The replaced generator may then be serviced when it is convenient.

Tank Cleaning:

As the water in the steam generator boils away, the minerals in that water come out of suspension and are deposited on the walls of the tank and on the electrodes. This process leaves the tank walls coated with a white or light brown colored mineral buildup. This buildup may be anywhere from soft and chalky to rock hard. The automatic drain cycle will minimize mineral buildup but, eventually, the tank will need cleaning.

Tank cleaning is indicated when: a) The unit has been in service for a period of time, a solids buildup is visible through the tank

walls, and the "normal" water level in the tank is rising, or;

b) The tank cleaning message (C02) is displayed.

TO CLEAN THE TANK, PLEASE REFER TO THE "TANK REMOVAL AND REPLACEMENT" AND THE "STEAM GENERATOR CHEMICAL CLEANING PROCESS" SECTIONS OF THIS MANUAL. (PAGE 30)

Tank Replacement:

Tank replacement is indicated if the tank body becomes deformed in any way, as this could cause leakage around the o-ring.

TO REPLACE THE TANK, PLEASE REFER TO THE "TANK REMOVAL AND REPLACEMENT" SECTION OF THIS MANUAL. (Page 30)

Electrode Replacement:

Electrode disintegration generally starts due to high conductivity water being present in the steam generator. Electrode disintegration sometimes occurs as a result of a combination of the following factors:

a) High voltage (especially 480 and 600 volts); b) Hard water (in excess of 20 grains/gal.);

c) Any unit with a malfunctioning drain system;

d) Softened water.

If the electrodes begin to disintegrate, the tank may turn black or red, and arcing or flashing may be visible inside the tank while it is operating. IF YOU NOTICE EXCESSIVE ARCING, SHUT THE UNIT OFF AND CALL THE FACTORY BEFORE RE-STARTING UNIT.

To replace the electrodes, please refer to the "Tank Disassembly and Electrode Replacement" Section of this manual. (Page 33)

RECOMMENDED PROCEDURE FOR STEAM GENERATOR TANK AND ELECTRODE REMOVAL, CLEANING, REPAIR AND REPLACEMENT

TANK REMOVAL AND REPLACEMENT - ALL MODELS

1) Turn steam generator tank off by pressing tank off button.

2) Drain the tank by pressing the drain button. It may take five minutes for a full tank to completely drain.

3) Once the tank is completely empty, turn off the power at the main disconnect or breaker.

4) Disconnect the steam hose from the top of the steam generator tank by loosening the hose clamp

with a screwdriver or 5/16" nutdriver. BE CAREFUL! The tank may still be hot to the touch, and

some steam may still be condensing in the tank.

5) Disconnect the power leads at the steam generator with a 7/16" wrench (three leads for 3-phase units, two leads for single phase). See wiring diagram, Figure 12-1, for more details.

6) Remove the tank from the cabinet by lifting it out of the drain adaptor. BE CAREFUL! The tank

may still contain hot steam or condensate.

7) It is preferable that you replace the tank with a new or rebuilt unit and take the current tank to the shop for servicing.

8) Install the tank into the EHU by lowering it into the drain adaptor. A small amount of high temperature grease or silicone lubricant may be used on the drain adaptor o-ring to help it seal properly.

After a couple of tank replacements the o-ring should de replaced as well.

9) Connect power leads and, on EHU-703 and 704, the loose end of the jumper wires to electrode studs using a 7/16" wrench (three leads for 3-phase units, two for single phase). Refer to the wiring diagram in your unit for specific information.

10) Connect the steam hose to the top of the steam generator with the hose clamp.

11) Check all wiring connections at the main power, contactor, and control voltage terminal blocks (Figure 14-1), as well as on the generator itself. Energize the circuit breaker or main disconnect. Refer to Start-up Section if you encounter any problems when restarting the unit.

STEAM GENERATOR CHEMICAL

CLEANING PROCEDURE

This procedure is intended as a guide only for the chemical cleaning of the generator in all EHU models. 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.

1) Obtain several gallons of muriatic acid. Muriatic acid is the name for commercial hydrochloric acid. It is available in most hardware, pool chemical, or farm supply outlets.

2) Remove the tank, following the "Tank Removal" directions in this manual.

3) Let the steam generator tank cool after removal from the EHU unit.

4) Split the tank, referring to the directions on page 33 of this manual, and examine the inside of the tank and the electrodes.

a. If the tank is black or dark brown, the electrodes may have disintegrated and chemical cleaning

may not be effective. The tank can be cleaned with the following process, but the electrodes may need to be replaced.

b. If tank and electrodes have a white/tan/grey mineral accumulations and/or the tank is partially

filled with loose lime accumulations, proceed with chemical cleaning.

5) Empty any loose deposits from the bottom tank half. Both tank halves and the barrier assembly, if present, can be cleaned using a scraper, a stiff bristle brush, and water spray as required. Refer to the directions on page 33 of this manual for details on removing the drain screen for further cleaning, if necessary.

6) Remove the electrodes from the upper tank half, following the directions on page 33 of this manual. Loose and/or soft deposits should be scraped from the exterior of the electrodes before chemical cleaning.

7) Prepare the chemical cleaning solution as per manufacturer's recommendations and fill a plastic bucket to a sufficient level to soak the electrodes. Be certain not to submerge the electrodes beyond the level of the screen.

8) Let the cleaning action take place for 15 minutes. Remove the electrodes from the bucket and rinse them thoroughly with a clean water spray.

9) Observe the electrodes to determine if another treatment is necessary.

10) It is not necessary for the electrodes to be cleaned down to bare metal. Removal of major accumulations is the only requirement.

11) Helpful Hints:

* Check the drain valve for proper operation & good flow when the tank is drained prior to

removal.

* With the tank removed, inspect the drain adaptor and hose from adaptor to drain valve to

ensure that it is free from deposits which may interfere with proper drainage.

12) Reassemble tank. Make sure o-rings are still on electrode terminals. Also check condition of steam generator o-ring. After a couple cleanings, it will need to be replaced. Make sure o-ring is sealed in its groove and not pinched when halves are put together. Do not over-tighten nuts that hold electrodes in place. This is an o-ring seal so nuts should be "snug".

13) Re-install the steam generator tank. Check out for proper operation.

TANK DISASSEMBLY, CLEANING, AND ELECTRODE REPLACEMENT

MODELS EHU-703 AND 704, SINGLE AND THREE PHASE

1) Using a 7/16" wrench, disconnect the jumper wires from the steam generator.

2) Remove 24 metal clips by pushing gently on top of each clip with a screwdriver while cupping the clip with the other hand.

3) Lift the top half of the tank free of the bottom half and rest it on the electrodes. Use a ¾" wrench to loosen and remove the nuts from the six electrode studs.

4) Lift the top tank half from the electrodes. Remove the o-ring from the lower tank half o-ring channel and put it aside for re-use. On high voltage units, lift the barrier assembly out of the bottom tank half.

5) Clean the tank halves and the barrier assembly (Figure 35-1), if applicable, using a scraper, stiff bristle brush, and/or water spray. Rinse the unit with clear water. If necessary, the drain screen may be removed for cleaning by removing three screws and pushing up through the bottom tank connection with a screwdriver handle or other blunt object. The drain screen snaps back into place

and is SECURED BY THE 3 SCREWS after cleaning. BOTH THE BARRIER ASSEMBLY AND

THE DRAIN SCREEN SHOULD BE REPLACED WITH NEW PARTS IF THEY ARE UNSERVICEABLE.

6) Install one electrode in the top tank half. Make sure the small o-ring is located at the bottom of the electrode stud. Push the electrode through one of the holes in the upper tank half. Slowly turn the electrode until it locks in place. Thread a nut, finger tight, onto the electrode stud. Repeat this process with the other five electrodes.

7) Turn the tank top half upright and rest it on the electrodes. Tighten the nuts on all the electrode studs with a ¾" wrench, so they are just snug.

8) Install the electrode jumper wires to the studs at the

top of the tank. Fasten one end of the jumper wire with a washer and a 1/4" hex nut, using a 7/16" wrench. There are three jumpers on a three-phase unit, and four jumpers on a single phase unit. On a single phase unit you should have only two loose ends ( Figure 34-1).

9) Install the o-ring in the bottom tank half o-ring channel.

A third hand or weight may be needed to hold one end of the o-ring in place while the other end is being installed.

10) Install the barrier assembly in the bottom tank half.

11) Lower the top tank half onto the bottom tank half. Line up the marks on the rim of the top and bottom tank halves to properly center the electrodes.

12) Look trough the top connection to make sure the o-ring is still in place.

13) Snap a metal clip over the flanges of the tank halves, midway between two alignment marks. Position another clip on the opposite side of the tank. Install all 24 clips in this manner.

Figure 34-1.

MODEL EHU-701, SINGLE AND THREE PHASE

Figure 35-1

1) Remove 24 metal clips by pushing gently on top of each clip with a screwdriver while cupping the clip with the other hand.

2) Clean the inside of the steam generator thoroughly unsing a scraper, stiff bristle brush and/or water spray and rinse with clear water.

3) High voltage units are supplied with a barrier/drain screen assembly in the lower tank half to increase tank life. Inspect the barrier/drain screen assembly and replace if necessary.

4) Place a flat washer and O-ring on each ¼" electrode stud and push the studs through the holes in the upper

Figure 35-2

tank half (Figure 35-2).

5) The mounting hole on each electrode is attached to the tank top with a slotted self-tapping screw.

6) From the outside, install a flat washer and ¼" hex nut on each electrode stud. Tighten these with a 7/16" wrench so they are just snug (Figure 35-2).

FILL

AND DRAIN SYSTEM REPAIR

General:

In the event of a "drain system failure" (C05) or a "fill system failure" (C06) indication on the three digit numerical display, perform the following steps to identify and correct the fault.

Drain System Failure:

Check for drain valve operation. With the unit on; press the tank on/off button, turning off the tank contactor (tank off light illuminated). Press the manual drain button. The drain light should go on and you should hear the drain valve operate with a sharp click. Repeatedly activate the manual drain button to determine if the valve is operating.

1) If the drain valve does not operate but the drain light is on, check for 24 VAC between the two

leads on the drain valve (Figure 28-1, 28-2). After checking, TURN THE POWER OFF

a) If 24 VAC was NOT

found, check wiring continuity to the circuit board. Repair broken wires as

necessary. If wires are intact, call the factory for assistance.

b) If 24 VAC W

AS found, measure the coil resistance of the drain valve with the leads

disconnected. The coil resistance should be 10 ohms; if it is not, replace the drain valve.

2) If the drain valves can be heard to operate but no water drains out, TURN THE POWER OFF

then:

a) Check for a plugged drain valve and/or plugged drain adaptor. It is often possible to see an

accumulation of solids in the inlet to the drain valve or in the neck of the steam generator. If this is the case, remove the generator and clean out the drain valve and tank drain adaptor. See tank removal section on Page 33.

Barrier

Barrier Retain

Drain Scree

Hex Nut

Washer

'O' Rin

Washer

b) While the tank is out, look into the lower end of the tank. Make sure the drain screen is in

place. Also check for accumulations of lime at the bottom of the tank. Refer to "Steam Generator Disassembly" and "Cleaning Procedure" sections to rectify these problems.

3) If the tank drains well when the water level is high but poorly or not at all when it is low, check the

duct pressure where the dispersion tube is mounted. A negative

duct pressure can cause

drainage problems. While this is relatively rare, it has been known to happen.

4) If the water backs up into the drain pan inside the unit, check for a blocked drain cup under the pan. If the drain cup is OK, check the drain piping for an accumulation of solids. Clean as required and increase the pitch of the drain piping if necessary. If long runs of horizontal drain pipe cannot be avoided, it may be necessary to develop some kind of drain flushing system. An air gap in between drain piping and drain hose from the EHU will allow "burping" of air from drain piping.

Fill System Failure:

Make sure the drain valve is not leaking. A leaking drain valve may appear to the humidifier as a fill system failure.

Check to see that the fill valve is operating. While the fill light is on, disconnect one of the fill valve leads (Figure 28-1, 28-2), then momentarily touch the lug to the coil terminal. You should be able to hear the valve operate.

1) If the fill light is on, but the valve is not operating, check for 24 VAC between the valve lead wires.

After checking, TURN OFF THE POWER.

a) If 24 VAC WAS NOT found, check the continuity of the wires back to the circuit board.

Repair broken wires as necessary. If wires are intact, call the factory for assistance.

b) If 24 VAC W

AS found, disconnect the fill valve leads and check the coil resistance. It should be

18 ohms. Replace the coil if necessary.

2) If the fill valve is operating but the unit fills too slowly, check for either low water pressure (less than 25 psi) or a partially plugged screen inside the inlet fitting. If the screen tends to plug too easily, it may well be removed and replaced by a larger filter in the water line external to the unit.

(NOTE: the nominal flow rate valve should be 0.31 gal/min. for each tank. The flow rate is

regulated by a flow washer in the valve inlet or on the EHU-704 by flow washers in the brass tee immediately downstream of the fill valve.)

3) If the valve makes humming or buzzing noises but fails to open:

a) Check for high water pressure (over 125 psi).

b) If a backflow preventer is used, crack open a fitting between the backflow preventer and the fill

valve. If this causes the fill valve to open, remove the backflow preventer from the system. Backflow preventers are not needed as the Series EHU-700 incorporates a 1 inch air gap as an anti-syphon feature.

For additional information on Armstrong Series EHU-700 Humidifiers, contact your Armstrong Representative and request Bulletin No. 596.

HUMIDISTAT DATA

AUTOCAL PROCEDURE

1. Measure the room humidity near the humidistat with an accurate hygrometer.

2. Turn the humidistat set point dial to match the reading of the hygrometer.

3. Push and hold the Autocal button for more than 3 seconds or until the internal red light turns On and Off.

SENSOR F

AILURE PROTECTION

The sensor is the most sensitive part of the humidistat and also the most exposed. In the case of a sensor failure in humidification mode, the humidistat will automatically assume a fail-safe output of 0%.

SPECIFICA

TIONS

Operating Conditions: 5°C to 50°C (32°F to 122°F)

• Control: 0% to 95% R.H. non-condensing

• Sensor: 0% to 100% R.H. (see Note 1.)

Resolution: ± 0.1 %

Repeatability: 0.5 %

Accuracy and sensor interchangeability:

± 2% R.H. from 0 to 100% R.H.

Range: 10% to 90% R.H. for 5 to 50°C

(41°F to 122°F)

Temperature effect: 0.05% / °F

Outputs: Isolated Triac: 30 Vac at ½ A max.*

0 to 5 VDC into 1 KΩ resistance min. 0 to 10 VDC into 2 KΩ resistance min. 0/5 VDC at 20 mA max. for both outputs.

Power: 24 VAC -15%, +10%; 50/60 Hz; 2 VA

Base and casing: Off-white; self extinguishing ABS plastic

* Triac outputs can only switch AC loads. Use relays when switching dc loads.

Note 1. Humidity sensor: Solid state humidity sensor. Suitable for normal, clean air. Not to be used in

corrosive or harmful environment.

DIMENSIONS

Figure 37-1. Dimension drawing. Duct Humidistat

Note: Specifications and equipment are subject to change without prior notice.

TABLE 5: SENSOR CHARACTERISTICS

Voltage between black and white wire, terminals #6 and #7

S S

HUMIDITY S ENSOR OUTPUT

0% 1.05 V

5% 1.19 V 10% 1.34 V 15% 1.48 V 20% 1.63 V 25% 1.77 V 30% 1.92 V 35% 2.06 V 40% 2.20 V 45% 2.35 V 50% 2.49 V 55% 2.64 V 60% 2.78 V 65% 2.93 V 70% 3.07 V 75% 3.21 V 80% 3.36 V 85% 3.50 V 90% 3.65 V 95% 3.79 V

100% 3.94 V

Wiring From Back

ecurity crew

Wiring From Top

1-5/8" (41 mm)

"Autocal" Button (Invisible)

3-1/4"

(83 mm)

(25 mm)

Base

1-1/4" (32 mm)

Cover

2-7/8"

(71 mm)

1-1/4"

(32 mm)

2-7/8"

(71 mm)

(50 mm)

Cover

4-1/2"

(114 mm)

3-3/4"

(96 mm)

15/16"

(23 mm)

AIR SUPPLY HIGH LIMIT HUMIDITY SENSOR

The A 17898 (H270) includes a high limit circuit. This allows the use of a second humidity in the supply air. Input signal goes to terminals #8 on the humidistat. High limit set point is preprogrammed at 85%. It can be readjusted using the

A19517 service tool. If you don’t use the high limit feature,

connect a 1 MegΩΩ, ¼ watt resistor between terminals 8 and 10 (supplied with the humidistat). Remember: this high limit function is not a safety device. For critical situations, provide installation with normal protections required to ensure a safe operation.

HUMIDITY

SET POINT RESET BY

OUTSIDE TEMPERATURE

The A17898 (H270) humidistat has an optional outdoor temperature sensor. This sensor is used to reset the humidity set point during the cold season to minimize condensation on windows and building structures.

When the outdoor temperature falls below the

selected high temperature, parameter HT (32°F in

the example Figure 41-2), the humidity set point will start to decrease. The lowest humidity set point will be reached at selected low temperature, parameter

LT (-20°F).

The set point decrease from original set point down to

the lowest set point determined by the parameter rE. In the example, Figure 41-2, rE was set to

20%, therefore the humidity set point dropped from 45% to 20%.

If you don’t use the outdoor reset feature, put a jumper between terminals 6 and 9 (supplied with the humidistat).

Table 4: Example showing proportional high

limit override signal in supply duct.

Control Output Level

Supply Humidity

Figure 38-1

Outside Air Temperature

32˚F 14˚F

-4˚F

00%

50%

85%

HT=32˚F

-20˚F

-40˚F

LT= -20˚F

User

Setpoint

rE=20%

20%

25%

30%

%RH

35%

40%

45%

APPLICATION EXAMPLE

Steam humidification system controlled by a 0 to 10 Vdc valve wired to output #1. Remote humidity display using 0 to 5 Vdc signal is wired to output #2. The humidity sensor is located in the return air duct. A proportional high limit humidity sensor is installed in the supply duct. An outdoor temperature sensor is installed in the fresh air duct.

Humidistat model number: H270-69-13-10-31

figure 42-1. Alternative humidistat wiring A17898 (H270)

H C

umidifier onnections

Humidifier

Connection

Terminals

On/Off High Limit Humidistat

(optional)

Air Flow Switch (optional)

Outside Air

Humidifier Location

Exhaust A

Main Humidity Sensor

Dimensional Information

Limited Warranty and Remedy

Conn. for

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 MER-

CHANTABILITY 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 Humidification Group,

816 Maple Street, Three Rivers, Michigan 49093 • USA Ph: (269) 273-1415 Fax: (269) 273-9500

527-G 6/06 Printed in U.S.A.

www.armstronginternational.com

Conn. for

Dispersion

2" ID Hose

Dispersion

1-1/2" ID Hose

EHU-704

Dimensions

EHU-701 EHU-703 EHU-704

Description

"A" Width "B" Height "C" Depth "D" Tank Drain - Side "E" Tank Drain - Front "G" Tank #2 Drain - Front "H" Steam Outlet #1 "I" Steam Outlet #2 "J" Water Supply - Side* "K" Water Supply - Front* "L" Electric Supply - Side "M" Electric Supply - Front "P" Clearance - Front "Q" Clearance - Left "R" Clearance - Bottom "S" Clearance - Right

in mm in mm in mm

18 457 19-1/2 495 33-1/2 851 23 584 31 784 31 784

11-1/2 292 14 356 14 356

6-5/8 168 3-1/4 83 3-1/4 83

10-5/16 262 14-3/4 375 14-3/4 375

——

12-1/2 318 12-1/2 318 12-1/2 318

—

8-1/4 210 9-1/4 235 9-1/4 235

15-1/2 394 3-3/4 95 3-3/4 95

3-1/8 80 2 51 2 51 4-1/2 114 2-1/2 64 2-1/2 64

18 457 24 610 24 610

4 102 4 102 4 102 5 127 5 127 5 127

4 102 24 610 24 610 * Water supply connection 3/8" compression. (Fill rate .31 gpm) Unit is designed to mount on 16" centers. 2 Lag screws & Bracket are provided for EHU-703 & EHU-704. Drain connection use 1" ID Hose. (Supplied) Drain rate 3 gpm.

EHU-703

Side

—

Side

Front

J D

EHU-701

28-3/4 730

14 356

Armstrong World Industries EHU-703, EHU-701, EHU-700, EHU-704 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual