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– 22 –

Checking The Burner Velocity Pressure

PS-10 & PS-11 air switches are factory calibrated. 
Do not adjust.

    

Check the velocity pressure by disconnecting both 
pressure sensing tubes from one of the high air

fl

 ow 

switch. Connect one end of your manometer to each 
sensing tube and start the fan. The permissible 
pressure range should be marked on the switches. 
If it’s close to the high or low trip points of the air

fl

 ow 

switches, you could have a problem: High pressure 
switch open means too much velocity; low pressure 
switch open means not enough velocity.

Jumper the switch from which you’ve disconnected the 
sensing tubes and get the burner running in high 

fi

 re. 

Your differential pressure should have dropped. If it is 
near the low switch trip point you need more air.

Some adjustments can be made by repositioning the 
burner pro

fi

 le plates. If the high switch is open, you 

can open the pro

fi

 le plates. If the low switch is open 

you can close the pro

fi

 le plates. Remember to keep 

the distance between the burner and pro

fi

 le plates 

the same opening on both the top and bottom of the 
burner when making these adjustments.

Depending on the motor amps you may want to 
change the speed of the fan if the unit has adjustable 
sheaves.

Don’t forget to remove the jumper and reconnect the 
sensing tubes to the switch.

Call factory with any questions.

Pro

fi

 le 

Plates

TROUBLESHOOTING GUIDE

Summary of Contents for WDF

Page 1: ...res 2 Ne pas actionner d interrupteur 3 Éteindre toute flamme ouverte 4 Appelez immédiatement votre fournisseur de gaz AVERTISSEMENT Une installation déficiente de même qu un mauvais réglage modification entretien ou maintenance peuvent occasionner des dommages matéri els corporels voire causer la mort Lire attentivement les instructions d installation d utilisation et d entretien avant d installe...

Page 2: ...on company when the claim is filed They will give you disposition instructions Packing We comply with the packing requirements of the transportation companies and your bill of lading proved that everything was in good condition when shipped That bill of lading contract requires them to deliver in perfect condition SECTION I FOREWARD As is the case with any fine piece of equipment care must be take...

Page 3: ... and critical components Rotate the fan s monthly Prior to beginning installation of a unit that has been in storage for weeks or months the unit and its compo nents should be closely inspected Shipments are made F O B Dallas Texas by flat bed truck The unit is securely strapped tied and blocked to prevent shipping damage All shipments are checked by an inspector before they are accepted by the ca...

Page 4: ...writers National Electrical Code and local governing bodies The following recommendations are not intended to supplant any requirements of federal state or local codes having jurisdiction Authorities having jurisdiction should be consulted before instal lations are made Local codes may require additional safety controls and or interlocks All installations in airplane hangers must be in ac cordance...

Page 5: ...g and positioning will assure a water tight curb unit installation Re check approval prints prior to installation Be sure that there are no obstructions to ducting and that proper planning has been exercised in connection of piping and or electrical services The curb assembly may be bolted or welded to either trusses or roof decking however connection to roof trusses is recommended The curb is des...

Page 6: ...les prévus pour résister à une chaleur d au moins 105 C F Field Piping Gas Piping All gas piping must be in accordance with the require ments outlined in the National Fuel Gas Code ANSI Z223 1 It is required that a ground union be installed adjacent to the manifold for easy servicing A drip leg and or filter should be provided upstream of the unit s inlet gas connection An additional shut off must...

Page 7: ...voltage drop Check the VA rating of control circuit transformer to determine maximum load 3 Mount and wire remote control panel thermostats temperature sensors and any other field installed controls as indicated on the unit control wiring diagram 4 Connect all wires to the appropriate field wiring terminals and any shielded or twisted wires as indicated on the unit control diagram 5 Field wiring s...

Page 8: ...m duct work is installed and free from obstructions 11 Check that fans turn free in housing 12 Check that the area around the unit is clear of flammable vapors or containers of flammable liquids 13 Check that all piping connections particularly unions are tight Check all gas piping for leaks using a soap bubble solution The most common types of problems found relative to the gas train itself is fo...

Page 9: ...will enable the fans To also enable the fans go to Unit Modes and enter AUTO this mode has four different functions that control the fans and unit operation They are a Time Clock Heating and Cooling Night Setbacks and signal from an external source to an auxiliary digital input To disable the fans go to Unit Modes and enter OFF NOTE A BACview or PC is required to change Unit Modes For a more detai...

Page 10: ...ire for approximately 10 seconds before modulating up The reading should be at least 0 5 microamps If the read ing is too low slowly turn the low fire adjustment on the modulating valve in or out until satisfactory readings are obtained When adjusting low fire there should be a continuous flame along the entire burner length without any blowout spots Install manometer at test port on the last tee ...

Page 11: ...s to a lower temperature setting while the unit is operating on high fire and observing cutoff The controls should be reset to settings shown below Make sure all the safeties and controls are working properly Suggested Control Settings Refer to Digital Control System user manual for default settings TS 02 Space Temperature Sensor Customer Discretion KP 01 Keypad Display Module Customer Discretion ...

Page 12: ...e is sensed during a purge period when no flame should be present the control will remain in purge with the gas valve off until the false flame disappears If the gas valve is found to be powered when it should be off or not powered when it should be on the ignition control will enter lockout with all outputs off Reset is accomplished by cycling the power off for a minimum of 5 seconds The Red LED ...

Page 13: ...gnition control 1 Check power source 2 Check and replace 3 Close or connect customer interlock 4 Enable the fan 5 Check time clock night setback thermostat and field installed controls for proper settings 6 Reset freeze stat by interrupting power Check for proper setting and burner operation 7 Check for power at damper motor and that end switch has been wired correctly to the N O normally open con...

Page 14: ...lenoids 5 Type of gas natural LP supplied different from factory required type Note components may change 6 Flame detection system not sparking or sensing flame see spark rod diagram P 001117 7 No voltage output terminals of ignition control 8 Main gas valve relay open 1 For DDC System 2 For RTC RE 26 1 Defective or misadjusted transducer PT 15 2 Transducer PT 15 wired incorrectly 3 Transducer PT ...

Page 15: ...1 signal conditioner provides signal conversion for a high impedance 2 10VDC signal source to drive a 24VDC solenoid The control should be powered by an isolated 24VAC transformer to drive up to a 5A dc solenoid Power Status LED A solid green LED indicates power and normal operation A slow blinking green LED indicates power but the 10 second start up delay has not completed A fast blinking green L...

Page 16: ...fier RE 26 terminals 7 8 2 Inspect 3 Check item B1 Check for 2 10 VDC input signal from UC 01 at terminals 1 2 Check for 0 20 VDC output signal to gas valve at terminals 5 6 4 Check DC Voltage on AO 1 1 Measure resistance across modulator terminals with connecting wires detached 2 Inspect Plunger should be installed to operate freely in solenoid sleeve 1 See valve adjustments in Section X 2 Close ...

Page 17: ...plus pressure drop of the valve 2 Read manifold pressure using manometer and compare with the pressure stated on the specification plate 1 Check setpoint on Unit Enable Potentiometer MP 15 2 Check Discharge Air Temperature Sensor TS 03 and wiring See Thermistor curve 3 Check setpoint with BACview or PC 1 Measure resistance across modulator terminals with red lead wires disconnected 2 Inspect wirin...

Page 18: ...of valve should point in direction of gas flow 1 Remove wires connected to amplifier terminals and measure resistance MR212 60 80 ohms M611 45 55 ohms 2 Inspect plunger should be installed to operate freely in solenoid sleeve 3 Disassemble valve for inspection of internal parts 1 Check for 24V AC at amplifier RE 26 terminals 7 8 2 Inspect 3 Check item B1 Check for 2 10 VDC input signal from UC 01 ...

Page 19: ...t 1 Open circuit in Space Temperature Sensor TS 02 or Discharge Air Temperature Sensor TS 03 1 Short in modulator coil circuit 2 Short circuit between amplifier and modulator valve 1 Incorrect Maximum Heating Discharge Temperature Setpoint 2 Incorrect Minimum Heating Discharge Temperature Setpoint 3 Incorrect space setpoint 4 Insufficient burner capacity G Continuous High Fire Electronics OK H Con...

Page 20: ... are energized and condensing unit or evaporative cooler is not on C Incorrect Space Temperature 1 Enable the cooling mode 2 Check auxiliary circuit wiring and contact 3 Adjust the air flow and external static pressure to match the unit rating plate DO NOT ADJUST SWITCHES 4 Change to correct setpoints See Digital Control User Manual 5 See Digital Control System User Manual 1 Check and or replace 2...

Page 21: ...tside Air Profile Damper To calibrate the Flow Station Pressure Transducer PT 15 1 Remove the tubes at the Low and High pressure fittings 2 The voltage at COM and OUT should be O VDC If not adjust Z do not adjust S 3 Make sure the Low and High fittings are clean do not insert any sharp objects into the pressure fittings make sure the static pressure sensing pitot tubes and all tubing is also clean...

Page 22: ...ve disconnected the sensing tubes and get the burner running in high fire Your differential pressure should have dropped If it is near the low switch trip point you need more air Some adjustments can be made by repositioning the burner profile plates If the high switch is open you can open the profile plates If the low switch is open you can close the profile plates Remember to keep the distance b...

Page 23: ... 4 6020 1 24 RS4 7020 1 36 RS1 2 3 8060 1 47 RS2 3 9060 1 57 RS1 3 10060 1 65 RS3 11060 1 73 RS1 2 12080 1 80 RS2 13080 1 87 RS1 14080 1 92 NONE 15080 1 98 UNPLUGGED NA 3 30 IN 3 JUMPER RS 04 MIXED AIR TEMP RE 56 RS 03 SAFETY CKT STATUS RE 09 RS 02 FLAME FAILURE SW 72 RS 01 100 OA or 100 OUTPUT IN 4 RE 27 RS 04 BURNER STATUS RE 65 RS 03 FAN STATUS RE 12 RS 02 CLOGGED FILTER SW 09 RS 01 AUXILIARY U...

Page 24: ...kets and recaulk as necessary q Check all nuts and bolts for tightness NOTE Keep screened air intakes clear of obstruc tions at all times WARNING Failure to comply with the general safety information may result in extensive property damage severe personal injury or death Periodic maintenance is essential to the efficient operation and extended service life of this equipment Failure to provide main...

Page 25: ... rear end fan housing must be removed to expose the grease plugs 2 Pillow Block Bearings Pillow block bearings are used on supply blower s Bearings have been prelu bricated with a number 2 lithium base grease Relu brication should be done with a similar grease using a low pressure grease gun Wipe all grease fittings clean before adding grease Grease should be added slowly in small amounts at frequ...

Page 26: ...o this end of the shaft 10 Slide the shaft through the next blower wheel hub and add another bearing Continue this procedure until the shaft is through all of the blower wheels 11 Place a bearing on each end of the shaft 12 Replace the old shims with new 13 Bolt the bearings in place and reattach the grease lines When installing a Sleevlock bearing see note at bottom of page 14 Adjust the shaft so...

Page 27: ...blowers are used for ventilation and heating D Belt Tensions and Adjustments Belt tension is adjusted during the initial run in and test periods at the factory However the belts are run as slack as possible to prevent excessive damage to the bearings yet tight enough to prevent slippage It is necessary therefore to tighten all belts during the first few months of operation and to check for proper ...

Page 28: ... on either side of the mixing plates should be removed with a wire brush Check visually that no holes in the mixing plates are blocked If any burner ports are plugged even partially clear them with a piece of wire See Maintenance of Gas Ports WARNING Do not enlarge burner ports or performance may be drastically affected If any mixing plates are loose or missing fasteners tighten replace as necessa...

Page 29: ...adequate once the initial piping debris is removed The operating conditions of the burner will determine how frequently maintenance is actually required P001117 Mestek Line Burners Use of an electric drill motor is not suggested unless both Pin Vise and Drill can be chucked up in a vari speed drill unit Use caution because it is easy to snap the bits off in a port when using a drill motor Removal ...

Page 30: ... WITH DDC MR212 High Fire Manifold Adjustments Note Low fire may need to be set first to get the burner to light off properly 1 Disconnect the plug where the Temperature Sensors TS 01 and TS 03 are wired to the unit control module UC 01 A minimum of 15vdc is required at terminals 5 and 6 on electric relay RE 26 This causes the valve to call for continuous high fire Caution The unit will shut down ...

Page 31: ...e voltage Above approximately 15 volts DC the Valve should be delivering full flow to the heater and the unit should be on full fire If the DC voltage is obtained on the Valve terminals but the heater does not respond as described the problem can be isolated to the valve itself or to the gas control manifold of the heater If the proper voltages are not obtained the problem can be isolated to the e...

Page 32: ...y must be ad dressed separately The heater inlet shall be located in accordance with applicable building code provisions for ventilation air Field constructed intake accessories should be prop erly designed to minimize the entry of snow and rain All ventilation air to the heater shall be ducted directly from the outdoors If in doubt regarding the application consult the heater manufacturer ETL lab...

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