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Armstrong EHU-700 Series, Installation And Maintenance Manual

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Armstrong EHU-700 Series Installation And Maintenance Manual Download Page 32

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.

32

Summary of Contents for EHU-700 Series

Page 1: ...gh 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 Armst...

Page 2: ...fier 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 2 ...

Page 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 ...

Page 4: ...ve 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 Figure...

Page 5: ...ngth 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...

Page 6: ... 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 2...

Page 7: ...gure 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 pa...

Page 8: ... 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 Fi...

Page 9: ... 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 ...

Page 10: ...posed 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 10 Modulating High Limit Sensor 6 10 Ft Outdoor Temperature Sensor Air Fl...

Page 11: ...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 informat...

Page 12: ... 12 Main Control Humidistat High Limit Humidistat Air Flow Switch Must be closed to run Micro Controller Printed Circuit Board N O Alarm Relay 24 V Secondary Power Transformer Side 1 Side 2 24 VAC Drain Valve A High Water Switch A 24 VAC Fill Valve Current Transformer Steam Generator A 24 VAC Contactor High Voltage Terminals LED Display Three Digit Numerical Display Panel Switches Drain On Off Tan...

Page 13: ... 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 LIGHT Indicates 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 second will op...

Page 14: ...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 supp...

Page 15: ...o 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 ...

Page 16: ...ss 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 16 ...

Page 17: ...is a function of the nominal current rating humidistat demand and the automatic capacity adjust ment 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 cyc...

Page 18: ...e 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 re...

Page 19: ... 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 conduc tivity and mineral build up in the tank It will vary in drain...

Page 20: ...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 ste...

Page 21: ...vate 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 t...

Page 22: ...uit 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 s...

Page 23: ...ized 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 ...

Page 24: ...he 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 th...

Page 25: ... Half Less Drain Screen 703 704 6 B3968 Steam Generator Top Half Holes Drilled 703 704 7A B3038 Electrode Replacement Assembly 1 Ph High Low Voltage 701 7B A10077 Electrode Replacement Assembly 3 Ph 701 8 A9745 Electrode Replacement Set Includes 6 ea electrodes O Rings 1 4 Nut 1 2 Nut 1 Ph 3 Ph 703 704 9A A9742 Drain Screen for Low Voltage 120 208 240 277 701 9B B2413D Drain Screen Barrier Assembl...

Page 26: ...ill 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 ...

Page 27: ... 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 52I C1833A Power Transformer 600v 701 703 704 53 B2857 Cable Assy Hex Display 701 703 704 54 B2856 Cable Assy L...

Page 28: ...gure 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 ...

Page 29: ...alls coat ed 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...

Page 30: ...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 ta...

Page 31: ...e 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 ta...

Page 32: ...ng 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 32 ...

Page 33: ... 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 th...

Page 34: ...ck for drain valve operation With the unit on press the tank on off button turning off the tank con tactor 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 ...

Page 35: ...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 WAS found disconnect the fill valve leads and check th...

Page 36: ...ONS 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 A max 0 to 5 VDC into 1 KΩ resistance min 0 to 10 VDC into 2 KΩ resistance min 0 ...

Page 37: ... Top Autocal Button Invisible Wiring From Back Security Screw Base Cover Cover 3 1 4 83 mm 4 1 2 114 mm 3 3 4 96 mm 1 1 4 32 mm 1 1 4 32 mm 2 50 mm 1 25 mm 2 7 8 71 mm 2 7 8 71 mm 15 16 23 mm 1 5 8 41 mm HUMIDITY SENSOR 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 ...

Page 38: ...et 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 ...

Page 39: ...ct 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 39 On Off High Limit Humidistat optional Air Flow Switch optional Main Humidity Sensor Humidifier Connections Humidifier Location Outside Air Exhaust Air Humidifie...

Page 40: ...es 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 prod u...

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