Armstrong World Industries EHU-703 manual

Inst allation 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 thr[...]

DANGER ELECTRICAL SHOCK HAZARD HIGH VOL T AGES EXIST INSIDE THE HUMIDIFIER T o 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. AL W A YS DISCONNECT THE POWER SUPPL Y A T THE CIRCUIT BREAKER OR SAFETY SWITCH BEFORE OPENING ANY[...]

T ABLE OF CONTENTS 3 SECTION 1: PREP ARA TION AND INST ALLA TION W ARNINGS.................................................................................................................. 2 PRE-INST ALLA TION................................................................................................... 4 Check shipment.........................[...]

PRE-INST ALLA TION 1) CHECK SHIPMENT A claim should be filed with the transportation comp any (and reported to Armstrong) if any items are missing or damaged. Y our shipment will arrive in two or three cartons. One carton holds the humidifier with the steam generator installed, the control humidist at and sensing element, two short steam hoses, hos[...]

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[...]

INST ALLA TION 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 unit s 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 o[...]

6) W A TER FILL SUPPL Y Connect the unit to the building water supply (25 to 125 psig pressure). Inst all 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 (POT ABLE) T AP W A TER IS RECOMMENDED. IF POT ABLE W A TER IS NOT A V AILABLE, CONSUL T THE F [...]

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, suppor[...]

CONTROL WIRING NOTE: Wiring to the low-voltage controls should not run in the same conduit s 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 t[...]

W all Mounted Control Humidist at: W all-mounted humidistat s are usually installed 4 f t. to 5 ft. above floor level. Of ten, the best location is beside a thermostat that controls temperature in the same sp ace that is to be humidified, if that loca- tion meets the following criteria: • The control humidistat should be located where it will be [...]

Duct Mounted Control Humidist at: Duct-mounted control humidistat s 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 humidistat s. 10[...]

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. 12 Main Control Humidistat High Limit* Humidistat Air Flow* Switch *Must be [...]

INSTRUMENT P ANEL 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: INDICA TOR, -DEMAND- % of humidistat control range. and DISPLA Y -CURRENT - actual current in amps. -% POWER- ratio of current draw to the nominal rating of th[...]

ST ART -UP PROCEDURE FOR ARMSTRONG SERIES EHU-700 HUMIDIFIERS The following steps should be performed on all newly inst alled 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 compartme[...]

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% [...]

15) V erify 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) T urn pow[...]

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 T ANK ON/OFF SWITCH ON THE HUMIDI- FIER BECAUSE THIS SWITCH DISCONNECTS THE STEAM GENERA TOR T ANK ONL Y . PRINCIPLE OF OPERA TION - AN OVERVIEW The Armstrong Series EHU-700 electroni[...]

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 W A TER 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 lev[...]

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 t ank on, and the fill and drain circuits idle, the current should fall slowly . When the unit is draining, the current should decrease at a mo[...]

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 shut- down and a dry contact is closed to enable a remote alarm. The diagnostic messages that result in the unit being shutdown are [...]

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 F AILURE: This routine checks for a failure to reduce current if the drain [...]

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 t ank will be off, and the diagnostics mode light will remain on. Output Circuit s: The diagnostics will first check all the output circuits: fill valve, d[...]

W A TER QUALITY AND TREA TMENT FOR EHU SERIES HUMIDIFIERS GENERAL Series EHU 700 electronic humidifiers use ordinary tap water in their operation. The quality of this water affect s 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[...]

Result s: -Excessive time needed to reach set point during star-up. -Poor humidity control. Remedy: -Add 1/2 teaspoon of Epsom salt s to the fill cup. After start-up the automatic drain program should maintain the unit at full cap acity . -If problem persists, cont act the factory . WHEN W A TER CONDUCTIVITY IS TOO HIGH Indicators: -W ater level ju[...]

25 See Drawings on Page 28 EHU-701, -703, -704 Series Electronic Steam Hu midifier Repa ir Parts Item Part N o. Descr iption Used On *1A D4417 1 Ph Low Voltage 120,208,240,277 Volts 701 *1B D4418 1 Ph High Voltage w/Barrier 380,480,600 Volts 701 *2A D4415 3 Ph Low Voltage (208, 240, 277 volts) 701 *2B D4416 3 Ph High Voltage w/Barrier (380, 480, 60[...]

26 Item Part No. Description Use d On 15 B2717 Drain Valv e Assembly w/ H ose & (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 W asher & Straight 3/8" Compression Fitting 701 17B B4480 Fill Valve w/Flow W asher & 90 Degree 3/8"[...]

27 Electrical Parts Item Part No. Description Used On 46 C2059 Display PC Board 701,703,704 47A A22925 Control PC Board Less Current M odule 701 47B A22926 Control PC Board Less Current M odule 703,704 48A B2895-7 CM-7 C urrent Module 701,703,704 48B B2895-12 CM-12 Current M odule 701,703,704 48C B2895-14 CM-14 Current M odule 701,703,704 48D B2895[...]

Figure 28-1. EHU-700 Parts List Figure 28-2. EHU-700 Steam Generator Repair Parts List 28 23 40 29 47 48 46 55 52 51 61 21 34 20 22 57 50 62 53 54 49 19 33 15 56 42 17 16 25 30 31 32 18 6 8 14 12 6 11 10 18 3[...]

MAINTENANCE RECOMMENDED MAINTENANCE SCHEDULE 1 TO 2 DA YS AFTER 1) Check unit operation. ST ART 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 of f button should not be depre[...]

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 F ACTORY BEFORE RE-ST ARTING UNIT . T o replace the electrodes, please refer to the "T ank Disassembly and Electrode Replacement&qu[...]

STEAM GENERA T OR CHEMICAL CLEANING PROCEDURE This procedure is intended as a guide only for the chemical cleaning of the generator in all EHU mod- els. 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 rubb[...]

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 nut [...]

T ANK DISASSEMBL Y , 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 clip s 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 t ank[...]

MODEL EHU-701, SINGLE AND THREE PHASE Figure 35-1 1) Remove 24 metal clip s 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 unit s are suppl[...]

b) While the tank is out, look into the lower end of the t ank. Make sure the drain screen is in place. Also check for accumulations of lime at the bottom of the tank. Refer to "S team Generator Disassembly" and "Cleaning Procedure" sections to rectify these problems. 3) If the tank drains well when the water level is high but p[...]

HUMIDIST A T DA T A AUTOCAL PROCEDURE 1. Measure the room humidity near the humidistat with an accurate hygrometer . 2. T urn 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 th[...]

DIMENSIONS Figure 37-1. Dimension drawing. Duct Humidistat Note: S pecifications and equipment are subject to change without prior notice. T ABLE 5: SENSOR CHARACTERISTICS V oltage between black and white wire, terminals #6 and #7 37 Wiring F rom To p "Autocal" Button (Invisib le) Wiring F rom Back S ecurity S crew Base Cover Cover 3-1/4&[...]

AIR SUPPL Y 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, connec[...]

APPLICA TION EXAMPLE S team 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[...]

Dimensional Information Limited Warranty and Remedy A H Q A H I S B B M K E G EHU-704 R K K E E M M EHU-703 EHU-701 S J J D D L L C Side Side P Conn. for Dispersion 2" ID Hose Conn. for Dispersion 1-1/2" ID Hose F ront in mm in mm in mm "A" W idth 18 457 19-1/2 495 33-1/2 851 "B" Height 23 584 31 784 31 784 "C&quo[...]