Reznor DV User Manual

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NOTICE:

The information contained on the following page(s) was produced

prior to May 1, 2014. On that date Reznor became part of

Nortek, Inc.

References to any other company afliations are no longer valid.

This manual refers to Reznor brand products that have been

discontinued for more than 10 years.

Some replacement parts may no longer be available from

our suppliers. Compatible parts may be substituted.

Please contact your Reznor Representative

with specic questions.

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0514 PDF Form Cover2

Indoor or Outdoor, Gas, Direct-

Fired, Makeup Air/Heating Systems

Index Page

Air Pressure ..................................... 4

Air Pressure Switches.................... 10

Blower Bearings ............................. 3

Burner ........................................ 4, 11

Circuit Indicator Board.................... 4

Control Locations............................ 8

Damper Motor .............................. 19

Direct-Fired Burner....................... 11

Dirty Filter Switch ........................ 19

Door Switch................................... 17

Drive Components .......................... 2

Electronic Circuit Board with

Diagnostic Lights ........................ 8

Emergency Cut Off ......................... 9

Evaporative Cooling Module ........... 5

Filters .............................................. 3

Firestat ........................................... 20

Freezestat ....................................... 20

Gas Control Systems .................... 11

Gas Pressure ................................... 3

Gas Pressure Switches................... 17

Ignition System .............................. 11

Inlet Air Controls ........................... 17

Limit Control................................... 9

Maintenance Schedule ..................... 2

Maintenance Section................. 2-7

Maintenance/Service Access ........... 2

Manifold Arrangements ................ 16

Operation/Service Section ...... 8-24

Outside Air Cutoff Control ............17

Photoelectric Smoke Detector ........ 20

Photohelic Pressure Sensor............ 19

Pilot Assembly ................................ 4

Potentiometer ................................. 19

Pressure Null Switch ..................... 19

Sensing Pressure Check................ 10

Troubleshooting ............................ 21

Wiring Diagram - In the main

electrical box on the unit

References:

Installation Manuals: Model DV, Form RZ-NA I-DV

Model RDF, Form RZ-NA I-RDF Model ADF(H), Form RZ-NA I-ADF

Replacement Parts Manual: Form RZ-NA P-DV/RDF/ADF or Form 740 for RDF; Form 741 for

DV, and Form 742 for ADF/ADFH

C E R T I F I E D

Operation/Maintenance/Service

Form RZ-NA O-DV/RDF/ADF

Obsoletes Form RZ-NA 440-OMS, 441-OMS, and 442-OMS

Applies to: Models DV, RDF, and ADF/ADFH

KEEP THIS BOOKLET FOR

MAINTENANCE AND

SERVICE REFERENCE.

FOR YOUR SAFETY WARNING: The use and storage of gasoline or other flammable vapors and liquids in the vicinity of this appliance is hazardous.

FOR YOUR SAFETY If you smell gas:

1. Open windows.

2. Don't touch electrical switches.

3. Extinguish any open flame.

4. Immediately call your gas supplier. WARNING: Improper installation, adjustment, alteration,

service, or maintenance can cause property damage, injury or death. Read the installation, operation, and maintenance

instructions thoroughly before installing or servicing this equipment.

WARNING: On makeup air heaters which also recir culate room air, outside ventilation air must be provided in accordance with the information shown on the heater rating plate.

Recirculation of room air may be hazardous in the presence of:

(a) Flammable solids, liquids, and gases; (b) Explosive materials (e.g. grain dust, coal dust, gun powder,

etc.); or

(e.g. refrigerants, aerosols, etc.).

Operating/Maintenance/Service

The information in this manual applies to Model Series DV, RDF, and ADF direct-fired heating/makeup air systems. As with any gas burning equipment, regular maintenance procedures are required to ensure continued safety, reliability and efficiency of the installation.

If service is required, this system should be serviced only by a qualified service person. Service information in this booklet is intended as a guideline for a qualified gas-fired equipment service person.

Form O-DV/RDF/ADF, P/N 148385, Page 1

DANGER: The gas burner in this dir ect gas-fir ed system is designed and equipped to pr ovide safe, controlled complete combustion. However, if the installation does not permit the burner to receive the proper supply of combustion air, complete combustion may not occur . The result is incomplete combustion which produces carbon monoxide, a poisonous gas that can cause death. Always comply with the combustion air requirements in the installation codes and operating instructions. The amount of air over the burner must be within the specified range. The burner profile plates are set at the factory to match CFM requirements. Do not adjust the burner profile plates without contacting the factory . F AILURE TO PROVIDE PROPER COMBUSTION AIR CAN RESUL T IN A HEAL TH HAZARD WHICH CAN CAUSE PROPERTY DAMAGE, SERIOUS INJURY, AND/OR DEA TH. Direct-fired installations should pr ovide for air changes as required by the applicable installation codes.

MAINTENANCE SECTION

Maintenance Codes

S = Safety (to avoid

personal injury and /or property damage)

R = Continued Reliability E = Efficient Operation

Maintenance Schedule

This direct-fired makeup air system is designed to require only a minimum amount of maintenance. Some maintenance procedures outlined in this Section require inspection only and some require action. Frequency requirements of each maintenance procedure are listed in the Maintenance Schedule. Depending on the environment and the number of operating hours, more frequent inspection and/or cleaning may be required to certain components.

Although maintenance requirements are minimal, the routine maintenance procedures in this Section are necessary to ensure safe, reliable, and/or efficient operation. The paragraphs which follow discuss the components and systems that require routine inspection/maintenance. At the beginning of each paragraph, there is a code indicating why that maintenance procedure is necessary. The legend for that code is shown on the left.

WARNING: Disconnect all power to the system before doing any maintenance. Failure to do so may cause electrical shock, personal injury, or death.

See Chart oLubricate bearings, Paragraph 1

Quarterly oCheck the filters, Paragraph 2

oCheck air pressure sensing tubes, Paragraph 4

Semi- oCheck blower belts, Paragraph 1 Annually oVerify gas pressures, Paragraph 3

oClean air pressure sensing tubes, Paragraph 4 oCheck indicator lights, Paragraph 5

Annually oCheck main burner and pilot assembly, Paragraph 6

1. Drive

Components

Form O-DV/RDF/ADF, P/N 148385, Page 2

The blower, motor and drive components are located in the blower cabinet. Remove the panels required to access the component(s) being serviced.

1A. Blower Bearings

All blowers are Class I with pillow block bearings. Clean the fitting and add type NLG-2 or -2 standard grade grease. Add grease with a handgun until a slight bead of grease forms at the seal. Be careful not to unseat the seal by over lubricating.

CAUTION: If the blower is unused for more than three months, the bearings should be purged with new grease prior to startup.

Recommended Bearing

Lubrication Schedule in Months

FIGURE 1 - Belt Tension

3/4 (19mm)

Bearing Bore Diameter (Inches)

RPM to 1000 6 6 6 1001 - 1 500 5 5 5 1501 - 2 000 5 4 5

1/2 to 1 >1 to 1-1/2 >1-1/2 to 1- 15/16

NOTE: If unusual environmental conditions exist ( temperatures below 32°F or above 200°F; moisture; or contaminants ) more frequent lubrication is required.

1B. Blower Belts

Check belts for proper tension and wear. Adjust belt tension as needed. Replace worn belts. Proper belt tension is important to the long life of the belt and motor. A loose belt will cause wear and slippage. Too much tension will cause excessive motor and blower bearing wear. If adjustment is required, adjust belt tension by means of the adjusting screw on the motor base until the belt can be depressed 1/2" to 3/4" (FIGURE 1). Tighten the lock nut on the adjusting screw. Be sure the belt is aligned in the pulleys.

2. Filters

Quantity and Size of Filters by Model

3. Manifold Gas

Pressure

If the system includes filters, check the filters quarterly. Filters could be either in an optional filter cabinet (DV/RDF/ADF) or in the optional inlet base (DV).

To access filters in a filter cabinet, remove the filter cabinet door panels. Clean or replace as needed. If removed, be sure to put blockoff plates in filter rack.

If the filters are in the perimeter of the inlet base of a Model DV; they are twoinch permanent filters. Remove and clean the filters as needed.

Dis

Type

Thickness

Model RDF with Optional Filter Cabinet

1 2 3

Model ADF/ADFH with Optional Filter Cabinet

300 500

700, 1200

Model DV with Optional Filter Section

109, 112

115, 118

122, 125

Model DV with Inlet Base with Filters

109, 112 115, 118 122, 125

(5)12x30-5/8 (5)12x30-5/8 (10)10x16 (10)10x16 (5)12x32 (5)12x32

(5)12x20 (5)12x20 (5)12x20 (5)12x20 (5)12x20 (5)12x20 (5)12x25 (5)12x25 (5)12x25 (5)12x25 (5)12x26 (5)12x26 (5)12x25 (5)12x25 (5)12x25 (5)12x25 (5)12x25 (5)12x25

(5)12x30-5/8 (5)12x30-5/8 (5)12x32 (5)12x32 (5)12x32 (5)12x32

osable Permanent Pleated Disposable

1" 2" 1" 2" 1" 2"

- - (3)12x35 (4)12x35 - -

- - (4)12x35 (4)12x35 - -

- - (4)12x24 (4)12x24 - -

- - (12)12x35 (10)12x35 - -

- (4)16x16 (4)16x16 (4)16x16 (4)16x16 (4)16x16

- (4)16x20 (4)16x20 (4)16x20 (4)16x20 (4)16x20

- (6)16x20 (6)16x20 (6)16x20 (6)16x20 (6)16x20

- (6)16x25 (6)16x25 (6)16x25 (6)16x25 (6)16x25

- (16)16x16 (16)16x16 (16)16x16 (16)16x16 (16)16x16

- (6)16x25 (6)16x25 (6)16x25 (6)16x25 (6)16x25

- - - (8) 10x12 - -

---(8)15x20--

- - - (16)20x20 - -

Semiannually, check the gas pressure to the burner and to the pilot. Measure both manifold pressure and pilot supply pressure with the blower in operation. Verify against pressures listed on the rating plate.

Pilot Regulator

Pilot Solenoid Valve

FIGURE 2 - Gas Pressure

Pilot Pressure Tap

Tap Locations

Valve

Gas

Supply

Inlet Pressure Ta

Valve

Regulator

Form O-DV/RDF/ADF, P/N 148385, Page 3

Manifold Pressure Tap

MAINTENANCE SECTION (cont'd)

4. Air Pressure

5. Circuit

Indicator Board (check lights)

FIGURE 3 - Circuit Indicator Board, P/N 151263

Profile plate sensing tubes should be checked quarterly and cleaned no less than semiannually. If the sensing tubes become even partially blocked, false pressure readings may be relayed. To clean, remove the screened end caps. Clean the screens and the tubes, if necessary. Replace the cleaned end caps. Check the pressure differential across the profile plate using a slope gauge. Air pressure differential should be between -.25" and -.75" w.c.

To attach the slope gauge, open the control compartment door panel. Just below the junction box, locate the tubing connections. Remove the cap at each connection and attach the slope gauge using two field-supplied 1/4" x 1/8" female NPT barbed tubing connections. For instructions on measuring air pressure, see Service Section, Paragraph 9.

The circuit indicator board is located in the control compartment electrical box (See FIGURE 7). Check operation of all indicator lights by switching lights that are not lit with one that is currently lit. Replace any burned out indicator bulbs (P/N 125189).

Row of Bulbs

Check bulbs not lit with other bulbs; replace any burned out bulbs.

6. Main Burner and Pilot Assembly

CAUTION: W ear eye protection while pressure cleaning and drilling.

WARNING: Do not enlarge burner ports or performance may be drastically affected.

Form O-DV/RDF/ADF, P/N 148385, Page 4

For the most part, the burner and pilot are self cleaning. However, if the application is extremely dirty or dusty, cleaning of the burner and pilot may be necessary. Inspect the burner annually. Follow these instructions. If it is necessary to replace any parts, use only factory-authorized replacements.

1)Turn off the gas and power supply to the system.

2)Remove the door panels in the burner/control cabinet. Locate the pilot.

3)Disconnect the two ignition wires (male and female quick connections)

and disconnect the flame sensor lead at the burner. Remove the setscrew located in the ignitor tube (setscrew holds the brass bushing in place). Carefully remove the brass bushing and the ignitor.

Check the hot surface ignitor for cracks or unusual deterioration. Check

the flame rod for integrity. Replace the flame rod (P/N 131188) and/or the hot surface ignitor (P/N 121865) if not in good condition.

4)Clean the burner and pilot by back-flushing, using high pressure air (40-

80 lbs). Continue until dust particles are completely expelled from both the upstream and downstream sides of the burner.

If air pressure does not unplug burner orifices or pilot tube, drill burner orifices with a Size #50 drill and/or pilot tube with a Size #55 drill.

Inspect the upstream and downstream sides of the mixing plates. Remove any accumulation of scale or foreign material with a wire brush. If any mixing plate fasteners are loose or missing, tighten or replace. Always use zinc plated or stainless fasteners.

If any cracks are present, replace that mixing plate. Because of the effect of flame temperature on the metal, fasteners may be difficult to remove. Be careful not to damage the gaskets that go between the mixing plates and the

FIGURE 4 - Burner End Plate showing Hot Surface Ignitor

NOTE: Model RDF units manufactured prior to 3/96 have a spark ignition system. Clean ultraviolet sensor and spark plug. Replace as needed.

FIGURE 5 - Direct Fired Burner

W ARNING: Burner profile plates are factory set to match CFM requirements. Do not adjust profile plates without contacting your Sales Representative for technical assistance.

Flame Sensor (not shown)

Ignitor

Location

Pilot Tubing

Burner - Full length of the

burner is made up of a series

of 6" or 12" burner sections in

a linear or oval configuration.

Burner End Plate

burner body. The gaskets are designed to overlap approximately 1/16" for airtight seal.

5)Follow Steps in reverse

order to re-install the pilot assembly. Close all panels and check for proper operation.

Mixing

Plates

Burner End Plate

7. Optional Evaporative Cooling Module (ADF/ADFH only)

Instructions for Replacing Evaporative Cooling Media

Media - Over time, excessive amounts of mineral deposits will begin to buildup on the media. Annually, scale and dirt should be washed off the entering surface of the media. Remove the pad retainers and screen. (See Steps 1-3 and 68 of Media Replacement Instructions.) Clean the media using a garden hose, mild soap, and a soft bristled brush. When the media becomes too clogged with mineral deposits and dirt that it cannot be cleaned, the pads should be replaced. The average pad life is approximately three cooling seasons.

Select the correct replacement part numbers and order media pads from your Distributor. Follow the instructions below and remove and replace pads as shown in FIGURE 6.

ADF / ADFH

300 24 x 12 2 105985 106021 106037 106029

500 24 x 12 3 105985 106021 106037 106029

700/ 48 x 12 4 107190 107194 107199 107201

1200 48 x 8- 5/ 8

1. Remove the three sheetmetal screws that hold the top pad retainer in

2. Remove the three sheetmetal screws that hold the bottom pad retainer in

3. Disengage the screen retainers from the sides of the media.

4. Disengage inlet screen from media pads and remove.

5. Slide all media pads horizontally away from the cooling module until

Media Pad

Sizes

(inches)

24 x 7- 7/ 8

24 x 9- 5/ 8

place. Release the top pad retainer from the cooling module.

place. Release bottom pad retainer from the cooling module.

clear of bottom reservoir pan. Dispose of properly.

Qty

Replacement Part No. (e ach)

Cellulose Fiber Glass Fiber

6" 12" 6" 12"

105986 106022 106038 106030

105989 106025 106041 106033

107191 107195 107200 107202

Form O-DV/RDF/ADF, P/N 148385, Page 5

MAINTENANCE SECTION (cont'd)

45°

Airflow

to Space

Outside

Airflow

7. Optional Evaporative Cooling Module (ADF/ADFH only) (cont'd))

Instructions for Replacing Evaporative Cooling Media (cont'd)

6. Replace media by sliding media pads over both support rails until back

stop is encountered. Media must be placed as shown in FIGURE 7.

7. Center screen on the incoming air side of the media.

8. Replace the two side screen retainers by fitting them between the side of the media pad and the side of the cooling module. The retainers should fit snugly, pinching the screen against the media pads.

9. Replace the bottom pad retainer by securing the retainer between the pad and the reservoir pan. Fasten with the three sheet metal screws removed in Step 2.

10. Replace the top pad retainer by securing the retainer between the pad and top of the cooling module. Fasten with the three sheet metal screws removed in Step 1.

FIGURE 6 - Removal and Replacement of Evaporative Cooling Module Media

Pad

FIGURE 7 Media must be installed with 45° angle sloping downward toward the incoming outside air.

Screen

Pad Retainer

Screw

Other Evaporative Cooling Module Maintenance

IMPORTANT: The media is made up of two different sheets of cooling material. Each sheet has its own unique angle. When replacing the cooling media, BE CERTAIN that the 45° angle slopes downward toward the incoming outside air (as illustrated above). If the media is not installed properly , water blowoff from the media pads will occur .

Water Feed Line and PVC Distribution Piping - Annually, the water supply

line and PVC water distribution pipe should be flushed of debris and contaminants.

1. Remove the media pads following the media replacement instructions.

2. Remove the water feed line from the downstream side of the ball valve

and unscrew the water bleed line barbed hose fitting.

3. Force a fresh water supply through the water inlet hose and thoroughly

flush the distribution pipe.

4. Reassemble being careful to install media with air flow direction as shown

in FIGURE 7.

Water Pump and Inlet Basket Screen (applies to system with float and pump control) -- Annually, the pump and inlet basket screen should be removed,

disassembled, and cleaned.

Form O-DV/RDF/ADF, P/N 148385, Page 6

WARNING: Do not expose pump motor or any part of the electrical box to water. Evaporative cooling pump is NOT submersible.

1. Disconnect the power supply to the unit.

FIGURE 8 - Remove Junction Box, Pump, and Float Switch as an Assembly

(Actual assembly may not appear exactly as in the photo. Applies to evaporative cooling module with float and pump control system only . )

2. Remove the service panel and the junction box door. Disconnect the twoline voltage power supply wires from the terminal block inside the junction box.

3. Disconnect the water feed line hose from the upstream side of the ball valve.

4. Unscrew the four sheet metal screws holding the junction box to the cooling module. Remove the junction box-pump-float switch assembly (See Figure 8).

5. Dislodge the inlet basket screen from the pump and clean any buildup of debris and dirt. Carefully remove the base cover plate from the bottom of the pump. Using a mild soap solution, wash all deposits from the inside of the pump and remove all debris from the impeller.

6. Reassemble the pump. Replace the parts in exact reverse order, being careful that everything is returned to its proper position.

Pump Motor

Junction Box (Note: Only 208V unit

will have a transformer in the junction box.)

Float

Switch

Pump

Carefully remove basket and snap-on cover plate to clean pump.

REFERENCE: Evaporative Cooling Module Troubleshooting Guide, Paragraph 20, page 23.

Form O-DV/RDF/ADF, P/N 148385, Page 7

OPERATION/ SERVICE SECTION

Controls - Location, Operation, and Service

FIGURE 9 - Control Identification and T ypical Locations (Model DV is shown as an example)

To service this system, it is necessary to understand the normal operation of the controls and the function of the diagnostic circuit board. Refer to the electrical box drawing in FIGURE 9 and to the individual illustrations to identify and locate each of the controls. The wiring diagrams for this unit are located in the main electrical box.

WARNING: Service work on this system should only be done by a qualified gas service person. The service information and the troubleshooting guides are intended as an aid to a qualified service person.

Control Relays

Ignition

Module

Maxitrol Amplifier

or Signal Conditioner

(high ambient limit control)

Circuit Board

Outside Air Cutoff

Bypass Damper Motor

Status Lights

Service Switches

High

24-Volt Terminals

Low

Time Delay

Relay

24-volt Terminals

Return

Air

Damper

Motor

Transformer

Motor Starter

Optional Dirty Filter Pressure Switch

Standard Pressure

Switches

Relay for

Optional 2-Speed

Starter Relay

NOTE: Wiring diagrams for the unit ar e located on the inside of the electrical box door.

8. Electronic Circuit Board with Lights

FIGURE 10 - Diagnostic Circuit Board, P/N 151263

Column of 13 indicator bulbs; always replace burned out bulbs, P/N

125189.

Form O-DV/RDF/ADF, P/N 148385, Page 8

Location: Control Compartment Electrical Box (See FIGURE 9) Function: The diagnostic lights on the circuit board are designed to assist in

troubleshooting. When the system is operating properly, the lights on the circuit board are lit. If the system fails to operate properly, all lights on the circuit board up to that one that represents the component or system that has failed will be lit. For more detailed information, refer to the Troubleshooting Guide in Paragraph 19.

Control Circuit Power

Control Switch Energized

Firestat Normal

Freezestat Normal

Starter Energized

Blower ON - High Air Pressure Normal

Blower ON - Low Air Pressure Normal

Manual and Auto Limits Normal

Outside Air Cutoff Normal

Low Gas Pressure Normal

High Gas Pressure Normal

Pilot Valve Energized

Gas Safety Valve Energized

Line Voltage Terminals

Service: Replacing burned out bulbs is the only service required. If a bulb is not lit, check the bulb by switching it with a bulb that is lit.

9. Limit Safety Controls

FIGURE 11 - Automatic Reset Limit Controls

Each unit has an automatic temperature activated limit control, a manual reset temperature activated limit control, and an electrical activated energy cutoff device.

• Automatic Reset Limit Control

Function: If the temperature of the discharge air reaches the setpoint, the limit will open the circuit to the burner system and close all burner and pilot valves. The limit control will be activated if total airflow is reduced or if gas pressure surges at the burner causing excessive discharge air temperature. The system will restart when the discharge air temperature decreases below the setpoint.

Service: Failure of this limit requires replacement of the control.

Model P/N Setting

RDF 86979 135°F ADF 122856 130°F ADFH 57953 170°F DV None

• Manual Reset Limit Control

Function: The manual reset limit has a higher setting than the automatic limit and requires manual resetting to restart the system. If for any reason the automatic limit should fail to protect against overheating, the manual limit will shutdown the system. Should the manual reset limit activate, check the entire system to determine the cause. Make any necessary changes or adjustments before restarting the burner system. Restart of the unit can be done only after the limit has been cooled and the reset button depressed

FIGURE 12 - Manual Reset Limit Controls

FIGURE 13 - ECO Limit Control

Setting 305°F, P/N 82414

CAUTION: If the manual reset limit activates, find and correct the cause before restarting the system.

Service: Failure of this limit requires replacement of the control.

Model DV - Manual Reset Limit with Capillary , Size 109-122 Setting 190°F, P/N 161437; Size 125, 205°F, P/N 161433

Model RDF Setting 150°F , P/N 82610

Reset Button

Model ADF - Setting 135°F, P/N 122858; Model ADFH - Setting 170°F, P/N 57953

• Emergency Cut Off Limit Control

Function: The emergency cut off is a fusible link high temperature limit which provides onetime redundant protection against overheating. If the temperature sensitive limit controls malfunction, the electrically activated emergency cutoff will shutdown the system.

Service: If this limit activates, the manual limit control has failed and must be replaced. The cause for activating the emergency cut off limit control must be found and corrected before re-starting the system.

Form O-DV/RDF/ADF, P/N 148385, Page 9

OPERATION/SERVICE SECTION (cont'd)

10. Air Pressure Switches

FIGURE 14 - Air Pressure Switch

Location: Control Compartment Electrical Box (See FIGURE 7.)

• Low Airflow Switch

Function: The low airflow switch is a velocity pressure switch that monitors airflow across the burner. Until the airflow attains adequate volume for combustion, the switch remains open. When the switch recognizes adequate air volume, it closes, permitting both the pilot and burner to operate. Low pressure switch is normally open; it closes on pressure rise at .25" w.c. Do not alter or adjust setting.

• High Airflow Switch

Function: The high airflow switch is a velocity pressure switch that monitors airflow across the burner. If the high airflow switch senses air velocity above the prescribed limit, it will shutdown gas flow to the burner. High pressure switch is normally closed; it opens when pressure rises above .75" w.c. Do not alter or adjust setting. Low and High Airflow Sensing Pressure Check: (requires slope gauge, several feet of 1/4" OD tubing and two 1/4" OD barbed tees.) Attach a slope gauge (0 to 1.0" scale) to the tubing connections in the control compartment. The two connections are located below the electrical control box. Remove the caps on the 1/8" NPT test connections and attach the slope gauge. (The recommended method for attaching the slope gauge is to use fieldsupplied 1/8" female NPT x 1/4" O.D. barbed hose connections.)

A) If the system includes an optional discharge damper, before measuring burner

differential air pressure, check to be sure that the damper is fully open.

B) With the blower operating, the pressure dif ferential on the slope gauge should

read between -.25" and -.75" w .c. If the slope gauge reading is within those limits, no adjustments are necessary .

C) When air pressure is within the proper range, turn the disconnect switch OFF.

Disconnect the manometer and the slope gauge. Replace the caps removed to connect the slope gauge.

Form O-DV/RDF/ADF, P/N 148385, Page 10

Pressure Switches and Bypass Damper Airflow (Applies to Model DV or Model RDF systems with Air Control Options

AR19, AR20, AR22, AR23, AR32, AR33, AR34, AR36, or AR37)

Adjustment of the bypass damper is controlled by the same low and high pressure switches described above. With a bypass damper, the volume of outside air supplied to the building is controlled by a manually set potentiometer (Option AR19 and AR22) or automatically by a pressure null switch (Option AR20 or AR23), a photohelic pressure switch (Option AR36 or AR37), or a fieldsupplied computer signal (Option AR33 or AR34). With Options AR19, AR20, AR33, and AR36 the supply air is varied by adjusting the position of a damper at the blower discharge. With Options AR22, AR23, AR34, and AR37, a return air damper is adjusted to vary the volume of return air. The unit is arranged so that a fixed amount (20%) of the rated volume flows over the burner at a constant velocity. The remainder (80%) of the rated air volume flows either through a balancing bypass damper or a combination of bypass and return air dampers. As the supply air volume is varied by the return air or discharge damper, the balancing damper is adjusted to maintain the required air velocity over the burner. See Paragraph 14 for inlet air control options.

Service: If the pressure check determines that an airflow switch is not functioning properly, the switch cannot be serviced and must be replaced with an identical replacement. Low air pressure switch is P/N 203932; high air pressure switch is P/N 203933.

11. Ignition System

FIGURE 15 - Ignition Control Module in the Electrical Compartment, P/N 157953

Location: Ignition Controller Module in the Control Compartment Electrical Box (See FIGURES 9 and 15.); Ignitor and Flame Sensor on the Burner (See FIGURE 16.)

Pilot Plate Assy

FIGURE 16 - Ignitor,

Flame Sensor P/N 121865, and Flame Sensor, P/N 134706, on the Burner

Ignitor

○○○

○○

○○○○○○○○○

Hot Surface Ignition System with Prepurge Time Delay and Flame Sensor with 100% Lockout

Function: The ignition system including the controller, the hot surface ignitor, and the flame sensor function to ignite and prove the pilot flame. When there is a call for heat, the modular ignition controller is energized. When the controller reads 1.4 amps going to the hot surface ignitor, it opens the pilot valve for a 15-second trial for ignition. After the pilot flame rod senses pilot flame, the main gas valve is energized. If the pilot flame rod does not sense a pilot flame, the controller shuts down the pilot valve for a 10-second interpurge and then opens it again for a second ignition trial. If pilot flame is not proven on the second trial, the ignition controller locks out and must be manually reset by an interruption of the main circuit (disconnect switch). If the burner ordered is over three feet long (Model RDF with burner Option BL7, BL8, BL9, BL10, BL11, or BL13), a second flame rod is located at the end of the burner. After the main gas valve(s) is energized, a 15-second trial to prove the second flame is initiated. Failure to recognize and prove flame travel to the opposite end of the burner will result in a pre-purge and re-try for ignition.

Service: The modular ignition controller does an internal self-check each time that it is energized and will lockout if not found to be functioning properly. If the ignition controller locks out and there is no other cause, the controller module must be replaced.

12. Gas Train Including Direct-Fired Burner, Gas Control Systems, Manifold Arrangements, & Gas Pressure Switches

FIGURE 17 - Single-Stage Gas Valve and Discharge Air Controller in Makeup Air Gas Control System, Option AG1

Direct-Fired Burner

Function: The design of the direct-fired burner and the controlled velocity of air at the burner ensure complete combustion through the full range of burner sizes and gas inputs as determined by the gas control system. The velocity of air is controlled by the profile plates and monitored by a standard low and high air pressure switch.

Service: Refer to Paragraph 6 in the Maintenance Section for instructions on burner maintenance.

WARNING: Burner profile plates are factory set to match CFM requirements. Do not adjust profile plates without contacting

your Sales Representative for technical assistance.

Makeup Air (100% Outside Air) Gas Control Systems

 Single-Stage Gas Valve for Makeup Air (Option AG1) (750MBH maximum)

The standard 24-volt, single state gas valve has an integral automatic electric on-off valve, a pressure regulator, a safety pilot valve, and a manual shutoff. The valve operates in response to a call for heat from a unit-mounted air con-

Form O-DV/RDF/ADF, P/N 148385, Page 11

OPERATION/SERVICE SECTION (cont'd)

12. Gas Train (cont'd)

Makeup Air (100% Outside Air) Gas Control Systems (cont'd)

troller that monitors discharge air temperature. The controller has a built-in setpoint selector from 0° - 100°F.

Due to different CFM settings and outside temperatures, the average downstream outlet temperature may not match the control setting exactly. After the installation is complete, adjust the setpoint to achieve the desired average outlet air temperature. See the valve manufacturer's literature provided in the owner's envelope for specifications, wiring, and operating information.

FIGURE 18 - Two-Stage Gas Valve and Discharge Ductstat in Makeup Air Gas Control System, Option AG3

FIGURE 19 - Mechanical Modulation Gas Valve in Makeup Air Gas Control System, Option AG49 and Option AG50

 Two-Stage Gas Valve for Makeup Air (Option AG3) (750 MBH maximum)

The single-stage valve is replaced by a two-stage valve having low fire and high fire operation. The two-stage valve is controlled by a unit-mounted ductstat that monitors discharge air temperature. The ductstat has a built-in setpoint selector from 60°-110°F. Available for use with natural gas only.

Due to different CFM settings and outside air temperatures, the average downstream outlet temperature may not match the ductstat setting exactly. After the installation is complete, adjust the setpoint of the ductstat to achieve the desired average outlet air temperature. See the valve manufacturer's literature provided in the owner's envelope for specifications, wiring, and operating information.

 Mechanical Modulation for Makeup Air (Option AG49, 40-160°F, or AG50, 40-120°F) (750 MBH maximum)

The mechanical modulation valve regulates the flow of gas based on the demands of the sensing bulb which is located in the discharge airstream.

See the valve manufacturer's literature provided in the owner's envelope for specifications and operating information. Available for use with natural gas only.

FIGURE 20 - Modulating Gas V alve

Form O-DV/RDF/ADF, P/N 148385, Page 12

 Electronic Modulation Gas Control for Makeup Air (100% Outside Air), Options AG30, AG31, AG32, AG33, AG35, AG36

Refer to the wiring diagrams in the main electrical box to determine which controls are on the system being serviced. NOTE: All field-supplied control wiring for Maxitrol controls must not be run inside conduit with line voltage wiring. To avoid any potential electrical interference, all field-supplied wiring for Maxitrol controls should be shielded wiring and must be grounded at the unit only.

Function: These gas control systems provide heated makeup air at a temperature controlled by a discharge air sensor. Makeup air gas controls apply only to systems with 100% outside air. Each system is equipped with electronic modulation controls that modulate burner flame from 1/25th of full fire input to full fire.

The electronic modulating-type gas controls act in response to discharge and/ or room air temperature sensors to change the gas flow rate to the burner, thus

lengthening or shortening the flame. The BTU output is varied (modulated) to maintain the required discharge air temperature.

These modulating gas control options are electronic because in all cases the gas valve acts to adjust the flow of the gas to the main burner in response to DC volts emanating from an amplifier. When the DC voltage is between 0 and 5 volts, the main valve seat is closed. Low fire flow is accomplished through a mechanical bypass. The low fire flow rate is set at the factory and should not need adjustment. However, if adjustment is necessary, refer to the Maxitrol literature that is included in the heater owner's envelope.

All of the electronic makeup air modulating gas control burner systems include low fire start. On an initial call for heat, the main burner ignites at its lowest input. During mild weather, the burner may then cycle off. Such full shutdown can be dictated by the outdoor ambient cutoff control. As the outside air temperature climbs above the setpoint of the outdoor ambient control, the burner control circuit is de-energized. When moderately cold outside air temperatures exist, the burner will modulate between low flame and high flame. Low fire start and the outdoor ambient control prevent the makeup air system from heating already warm air and providing "too much" heat to the building.

For troubleshooting guides and further explanation of Maxitrol Series 14 and 44 electronic modulation gas control systems, refer to the Maxitrol literature in the owner's envelope.

The Option AG30, AG31, AG32, and AG35 electronic modulation systems are comprised of Maxitrol Series 14 controls for makeup air. Options AG30 and AG31 systems electronically maintain a constant discharge air temperature in the range of 55-90°F. Option AG31 includes an overriding thermostat. Option AG32 system will maintain a constant discharge air temperature in the range of 80-130°F. Option AG35 maintains a discharge temperature range of 120-160°F.

FIGURE 21 - Maxitrol Series 14 Components used in Makeup Air Gas Contr ol Options AG30, AG31, AG32, AG35

FIGURE 22 - Maxitrol Series 44 Components used in Makeup Air Gas Contr ol Option AG33

Amplifier, P/N 148590 Mixing Tube

T emperature

Selector

Temperature Sensor

Option AG33 electronic modulation system is comprised of Maxitrol Series

44 controls for makeup air. The low limit (20-60°F) and the high limit (60140°F) for control of discharge air temperature are set at the amplifier located in the control compartment. The space temperature is set at the remote selectrastat (55-90°F range) located in the space. When the temperature is below the space temperature setpoint, the control system operates the burner to automatically adjust the discharge air temperature within the maximum and minimum limits set on the amplifier.

Temperature

Amplifier, P/N 157915

Sensor, P/N 119617

Mixing

Temperature Selector, P/N 86990

Tube, P/N 90323

Form O-DV/RDF/ADF, P/N 148385, Page 13

OPERATION/SERVICE SECTION (cont'd)

12. Gas Train (cont'd)

 Electronic Modulation Gas Controls (cont'd)

FIGURE 23 - Components of the Gas Control System used in Option AG36 designed specifically for paint booths - controls are mounted on a remote console

FIGURE 24 - Maxitrol Signal Conditioner for Computer Control

Option AG36 is a special application gas train that is designed for controlling

the environment of a paint booth operation. The system includes a Maxitrol A1494 amplifier, discharge air temperature sensor, dual remote discharge air temperature selector (drying selector 80-140°F and a spray selector 60-90°F), and two switches to control the operation of the modulating gas valve.

Selector,

P/N 133230

Amplifier, P/N 133229

 Electronic Modulation Makeup Air Gas Control Option AG37

Maxitrol A200 Signal Conditioner, P/N 134170

Function: Control Option AG37 does

not have a duct sensor or amplifier. Instead, a Maxitrol A200 signal conditioner is activated by a customer-supplied input signal (either 4-20 milliamps or 0-10 volt) to control the modulation of the gas valve.

FIGURE 25 Modulating Gas V alve

Form O-DV/RDF/ADF, P/N 148385, Page 14

Makeup Air with Recirculation Air Gas Control Systems

 Electronic Modulation Makeup Air with Recirculation Gas Control Options AG47, AG48, AG51

Function: These makeup air with recirculation gas control systems provide a mix of outside and recirculated air heated to a temperature controlled by a discharge air sensor. Each system is equipped with electronic modulation controls that modulate burner flame from 1/25th of full fire input to full fire and adjust the outside air damper in response to outside and return air sensors.

Both the flow of the gas to the main burner and the outside (bypass) air damper position are adjusted in response to DC volts emanating from an amplifier. When the DC voltage is between 0 and 5 volts, the main valve seat is closed. Low fire gas flow is accomplished through a mechanical bypass. Minimum outside air is 25%. Carbon dioxide (CO maintained to a level in compliance with ANSI Z83.18 requirements.

For troubleshooting guides and further explanation of Maxitrol Series 14 and 44 electronic modulation gas control recirculation systems, refer to the Maxitrol literature in the owner's envelope.

Option AG47 electronic modulation system is comprised of Maxitrol Series 14 controls for makeup air with recirculation. The system electronically operates the burner and/or the outside air damper to maintain a constant discharge air temperature in the range of 40-95°F.

) in the discharge air of the unit is

FIGURE 26 - Maxitrol Series 14 Components used in Recirculation Air Gas Control Option

AG47

FIGURE 27 - Maxitrol Series 44 Components used in Recirculation Air Gas Control Option AG48

Discharge

Air Sensor,

P/N 204453

Amplifier, P/N 204454

Selector,

P/N 204455

Return Air Sensor, P/N 204452 Outside Air Sensor, P/N 204452

Option AG48 electronic modulation system is comprised of Maxitrol Series 44

controls for makeup air with recirculation. The low limit (20-60°F) and the high limit (60-140°F) for control of discharge air temperature are set at the amplifier. The space temperature is set at the remote selectrastat (55-90°F range) located in the space. When the temperature is below the space temperature setpoint, the control system operates the burner and/or the outside air damper to automatically adjust the discharge air temperature within the maximum and minimum limits set on the amplifier.

FIGURE 28 - Option AG51 includes Maxitrol Series 44 Components used in AG48 plus a Remote Sensor

Selector,

P/N 204451

Amplifier, P/N 204450

Discharge

Air Sensor,

P/N 204453

Return Air Sensor, P/N 204452 Outside Air Sensor, P/N 204452

Option AG51 electronic modulation

system is comprised of the same Maxitrol Series 44 controls as Option AG48 plus a remote sensor/selector.

Remote Sensor/ Selector, P/N 204456

Service - ALL Gas Controls: Check all electrical connections. A qualified

service person should refer to the control manufacturer's literature for assistance in identifying problems and determining the correct solution. None of the controls have field replaceable parts. All components must be replaced with identical replacement parts.

Form O-DV/RDF/ADF, P/N 148385, Page 15

OPERATION/SERVICE SECTION (cont'd)

12. Gas Train (cont'd)

Manifold Arrangements

Description: The manifold is the gas train from the gas supply connection to the burner. The manifold selection ordered determines the manifold arrangement including all of the gas train components except the main control valve. Manifold arrangements are available for varying BTUH ranges and gas controls and meet ANSI, CSA, FM or GAP (former IRI) requirements.

All manifold arrangements include two 5psi rated manual shutoffs. These systems are designed to operate on a natural gas supply differential

pressure range of a minimum of 4.3-5.0" w.c. plus the manifold pressure drop. Maximum supply pressure depends on manifold selection; see below. If the gas supply pressure is above the maximum allowed, it is necessary to install a field-supplied step-down gas regulator in the supply line. Order and install the appropriate Gas Regulator Kit, Option CZ1 (1") or CZ2 (1-1/2"). Follow the instructions provided with the kit. Measure the gas pressure between the stepdown regulator and the unit.

Maximum Supply Pressure by Manifold

(Refer to the wiring diagram or rating plate to identify the manifold on the system being serviced.)

Manifold Option BM75, BM76, BM77 - 1/2 psi Manifold Option BM78, BM79 - 2 psi Manifold Option BM80, BM81 - 5 psi

The table below lists the minimum supply pressure required for manifold and gas control combinations. Refer to the wiring diagram to be sure which combination of options applies to the system being serviced. (NOTE: Not all options are applicable on all models.)

Minimum Supply Gas Pressure ("w.c.) for Full Fire

Manifold Option with Gas Control O

tion

Manifold Size

MBH

250 500

750 1000 1250 1500 1750 2000 2500 3000

BM75

AG1

1" 1" 1" 1"

Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro Nat Pro

4.01.44.0N/A 4.1 1.6 4.31.54.41.64.61.64.51.65.11.8

5.31.95.0N/A 5.8 2.3 6.22.26.02.35.21.95.01.75.31.9

7.52.76.8N/A 8.5 3.3 9.53.38.43.36.12.35.72.05.51.9

AG3

AG 30, 31, 32, 33, 35,

BM76 BM78

36, 37, 47, 48, or 51

12.4 4.7 11.7 4.6 7.4 2.8 6.7 2.4 5.8 2.1

If the gas train includes either or both high and low gas pressure switches, the switches monitor gas pressure downstream from the safety valves.

If the gas pressure in a system equipped with a high gas pressure switch (standard with manifold Options BM 78, 79, 80 and 81; Option BP2 with other manifolds) exceeds the setpoint, the switch will open the electrical circuit to the burner, stopping all gas flow. The high gas pressure switch is a manually reset device.

A low gas pressure switch (Option BP3) will shutoff the gas flow if the gas pressure drops below the setpoint of the low pressure switch. The low gas

BM77

AG 49, 50

BM80 BM81BM79

AG 30, 31, 32, 33, 35, 36, 37, 47, 48, or 51

1" 1-1/4"

9.13.58.02.96.22.2

11.2 4.3 9.6 3.5 6.6 2.4

13.6 5.3 11.5 4.2 7.2 2.6

16.5 6.3 13.7 5.0 7.8 2.8

23.3 8.9 18.9 7.0 9.4 3.4

1-1/4"

11.3 4.1

Form O-DV/RDF/ADF, P/N 148385, Page 16

pressure switch will automatically reset when the gas pressure rises above the setpoint.

(NOTE: Both high and low gas pressure switches incorporate a vent limiting device and do not require venting to the outdoors when used in an application indoor installation.)

FIGURE 29 - Gas Pressure Switches

13. Outside Air Cutoff Control (Option BN2)

FIGURE 30 - Outside Air Cutoff Control, P/N 126170

Low Gas Pressure Switch, P/N 204375 (automatic)

Location: The control is in the electrical box (See Figure 7.); the sensor is in

the air inlet. Function: After sensing pilot flame, the burner ignites at its lowest input rate.

The "amount of heat" required to reach the desired discharge temperature also depends on the temperature of the incoming outside air. The outside air control is factory set at 60°F (adjustable 25-250°F). The burner reacts differently depending on the entering air temperature and the setting on the outside air control. The burner --

• may not ignite (pilot valve will not open); If the actual temperature of the outside air is above the setpoint on the outside air control, the burner will not ignite.

• may modulate to satisfy discharge setting;

• would shutdown completely only on Option BN2 control, once burner has been fired; or Modulating operation will depend on the temperature rise between the outside air and the discharge air setting.

• may remain on continuous low fire. If the outside air control is set too high, the burner will continuously burn on low fire as long as the control switch is set to "winter".

When the outside air control is set properly for the climate, the system blower will continue to provide the required makeup air (ventilation) at the ambient outdoor temperature (burner not operating) even when the control switch is set to "winter".

Service: If the control does not function properly, replace it with an identical switch.

High Gas

Pressure

Switch,

P/N 204297

(manual reset)

14. Door Switch (Option BX1)

FIGURE 31 Door Switch, P/N 124253

15. Inlet Air Controls

Location: The control is installed on an overhead door opening to control the operation of the heater to coincide with the opening and closing of the door. Function: The function of the switch is to energize and interlock the heating unit when an outside overhead door reaches approximately 80% of full open travel. The switch will de-energize the furnace when the overhead door closes approximately 20%. The complete switch includes a limit switch electrically wired to the heater and a roller yoke for mechanical activation by a fieldsupplied trigger on the overhead door.

Description: The system is equipped with one of the 11 types of inlet air control arrangements listed below. All systems provide a constant flow of outside air across the burner at the required air volume (CFM). Refer to the wiring diagrams in the main electrical box to determine which controls are on the system being serviced.

Form O-DV/RDF/ADF, P/N 148385, Page 17

OPERATION/SERVICE SECTION (cont'd)

15. Inlet Air Controls (cont'd)

W ARNING: Burner profile plates are factory set to match CFM requirements. Do not adjust profile plates without contacting your Sales Representative for technical assistance.

lOption AR1 - a constant supply of 100% makeup air lOption AR19 - 100% outside makeup air with variable supply air volume

(CFM). The discharge damper controlling the variable air supply is controlled by a manually set remote potentiometer and can be varied from 100% to 2025% of total rated airflow (CFM). In response to changes in the discharge damper setting, the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner. lOption AR20 - 100% outside makeup air with variable supply air volume (CFM). The discharge damper controlling the variable air supply is automatically controlled by a building pressure sensor and can be varied from 100% to 20-25% of total rated airflow (CFM). In response to changes in the discharge damper setting, the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner. lOption AR22 - a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers. The volume of outside air is regulated by a remotely located, manually set potentiometer. lOption AR23 - a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers. The volume of outside air is regulated automatically by a remotely located building pressure sensor. lOption AR32 - a combination of outside makeup air and bypass return air including a two-position actuator. The two position actuator changes the position of the damper to provide either 100% outside air or 20% outside/80% return air. Control is from a SPDT toggle switch mounted on a 4x4 box (or if ordered, the switch is mounted on a remote console). lOption AR33 - 100% outside makeup air with variable supply air volume (CFM). The discharge damper controlling the variable air supply is automatically controlled by a 0-10 VCD or 4-20 milliamp signal. In response to changes in the discharge damper setting, the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner. lOption AR34 - a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers. The volume of outside air is regulated by a 0-10 VCD or 4-20 milliamp signal.

lOption AR35 - a constant supply of 100% makeup air to the unit but in- cluding a two-position inlet shutoff damper that closes the dampers when the system is not operating. The damper attaches to the duct flange of the optional inlet base (used only with the optional inlet base that has three closed sides and a duct connection for outside air).

lOption AR36 - 100% outside makeup air with variable supply air volume (CFM). The discharge damper controlling the variable air supply is automatically controlled by a remotely located photohelic pressure sensor. In response to changes in the discharge damper setting, the bypass damper balances the volume of air so that the required fixed amount of air volume flows over the burner.

lOption AR37 - a combination of outside makeup air and bypass return air including modulating return air and bypass air dampers. The volume of outside air is regulated by a remotely located photohelic pressure sensor.

Airflow Dampers

Form O-DV/RDF/ADF, P/N 148385, Page 18

Function: Dampers operate in response to controls to provide the rated flow of

makeup air to the building. Minimum outside air is 20-25%. Service: Clean all dampers of dust or dirt.

Damper Motor

FIGURE 32 Damper Motor

Function: The damper motor automatically actuates the return air, bypass,

and/or discharge dampers in response to an electrical control device. The damper motor is direct-coupled to the dampers so there is no damper linkage to adjust. Service: There is no service required on these motors other than external cleaning. If the motors need replaced, replace with an identical damper motor.

Potentiometer

FIGURE 33 Potentiometer, P/N 16110

Pressure Null Switch (automatic building pressure sensor)

FIGURE 34 Pressure Null Switch, P/N 88052

Photohelic Pressure Switch (automatic

building pressure sensor)

FIGURE 35 Photohelic Pressure Sensor, P/N 159893

Function: The potentiometer is a manually set switch that operates either the

discharge damper (Option AR19) or the return air damper (Option AR22) providing a mixture of return and outside air. It is a remotely located switch that requires manual adjustment.

Service: If the potentiometer does not function properly, replace it with an identical switch.

Description/Function: The pressure null switch is a diaphragm operated differential pressure switch used in makeup air applications to automatically control building pressure. It maintains a selected positive or negative pressure setpoint by changing the amount of outside air being introduced to the building through modulating outside air damper. As more pressure is required in the building, the pressure null switch activates the damper motor driving the outside air damper towards the full open position (causing the bypass return air damper to go toward the closed position). Conversely, as less pressure is required, the switch drives the outside air damper in the opposite direction.

Service: Clean the tubing and the screened ends of the pressure tap vents. Be sure that the switch is installed with the diaphragm in a vertical plane and that the pressure taps are sheltered from the wind. For further service, follow the manufacturer's instructions included with the switch.

Description/Function: The photohelic pressure switch is a phototransister relay operated positive pressure switch used in makeup air applications to automatically control building pressure. It maintains a selected positive pressure setpoint by changing the amount of outside air being introduced to the building through a modulating outside air damper. As more pressure is required in the building, the switch activates the damper motor driving the outside air damper towards the full open position (causing the bypass return air damper to go toward the closed position). Conversely, as less pressure is required, the switch drives the outside air damper in the opposite direction.

Service: Clean the tubing and the screened ends of the pressure tap vents. If the interior of the switch is protected from dust, dirt, corrosive gases and

fluids, years of trouble-free service may be expected. Zero adjustment should be checked and reset occasionally to maintain accuracy; follow the manufacturer's instructions included with the switch.

There are no field-repairable parts in this switch. If the switch should require repair, contact either the system or the switch manufacturer concerning switch replacement or repair.

16. Dirty Filter Switch

FIGURE 36

- Dirty Filter Pressure Switch, P/N 105507

Location: Switch is located in the main electrical box (See FIGURE 9); sen-

sor tubes run to either side of the filter rack; indicator light is on the remote console.

Function: The dirty filter switch is a pressure switch that activates an indicator light on the remote console when the filters need cleaned or replaced (See Service Section, Paragraph 2). This switch is only on systems with an optional console that includes a dirty filter light. The pressure switch is set during in-

Form O-DV/RDF/ADF, P/N 148385, Page 19

OPERATION/SERVICE SECTION (cont'd)

16. Dirty Filter Switch (cont'd)

17. Photoelectric

Smoke Detector (Option SA1)

stallation so that the light will be activated at approximately 50% filter blockage. Contacts should close at .17 to 5.0" w.c. ± .05" w.c.

Service: Clean the sensor tubes. If the dirty filter indicator system still does not function properly, check the setting of the switch. With clean filters in place, blower doors closed, and blower in operation, decrease the pressure setting by adjusting the setscrew on the switch clockwise until the filter light is energized or screw is bottomed out. At that point, adjust the setscrew three full turns counterclockwise or until the screw is top ended.

If it is determined that the switch needs replacing, use an identical switch. When a new switch is installed, it must be manually set; follow the instructions above.

Location: Field-mounted in the discharge ductwork.

Function: The detector will shut down the system if smoke is detected in the

FIGURE 37 - Photoelectric Smoke Detector (cover removed), P/N 159553, used with sampling tube, P/N 159714

discharge ductwork. Service: Clean the external surface.

Check the wiring and connections.

18. Firestat (Option BD5)

FIGURE 38

- Firestat,

P/N 42782

19. Low Temperature Limit (Freezestat), Option BE2

FIGURE 39 P/N 126170

Location: Field-mounted on the discharge ductwork so that the sensor ex-

tends into the duct. This control requires manual reset so it should be mounted in an accessible location.

Function: The firestat will shut down the system if the temperature in the ductwork reaches 200°F. The switch must be manually reset.

Service: Clean the external surface. Check the wiring and connections.

Location: The control is in the blower section electrical box; the sensing bulb

is field-mounted in the discharge duct. Function: The freezestat will shut down the system if the discharge tempera-

ture falls below the setpoint. The switch is automatic and will startup the heater when the temperature reaches the setpoint.

Service: Clean the external surface. Check the wiring and connections. Freezestat Controller is P/N 126170.

Form O-DV/RDF/ADF, P/N 148385, Page 20

20. Troubleshooting

Chart 1 - System Troubleshooting (Check the diagnostic lights.)

Sympt om or Problem Cause and Remedy

Disconnect switch is close d, but "control power" light is

Disconnect switch is close d, but "fire st at normal" light is

Disconnect closed, blower switch in test position, "

is lit, but "freezestat" light is not lit

Disconnect closed, blower switch in test position, "

freezestat

" the blower moto r is not o

Disconnect closed, blower switch in test position, "

freezestat

" motor is not o

Disconnect closed; blower switch in test position;

freezestat

" motor is o

Disconnect closed; blower switch in test position; "

freezestat

" blower motor is operating; but the "high air light" is not lit.

Disconnect closed; blower switch in test position;

freezestat

" but the "limit control normal" li

Disconnect closed; blower switch in test position; "

freezestat

co ntrol normal

normal" light is not lit.

10. freezestat

control normal

are lit; but the "low gas pressure normal" light is not lit .

11. freezestat

controls normal

low gas pressure normal

" normal" light is not lit.

12.

control switch is in "

normal energized

lit; but igniter is not becoming energized or beginning to glow.

13.

control switch is in "winter" position; "control power", high gas normal; "low gas no rmal"; "firestat normal"; "system switc h energized"; "starter energized" and "freezestat normal" lights are lit; ignitor glowing but "pilot valve normal" light (thus the pilo t valve)

" lights are lit, but "starter energized" light is not lit and

erating.

" and "starter energized" lights are lit, but the blower

erating.

starter energized

" and "

erating; but the "low air light" is not lit.

starter energized

", "

starter energized

", "

starter energized

", "

" lights are lit; but the "ambient (outside air) cutoff

Disconnect closed; blower switch in test position; "

starter energized

", "

ambient (outside air) cutoff normal

" and "

Disconnect closed; blower switch in test position; "

starter energized

", "

ambient (outside air) c utoff normal

", "

" lights are lit; but the "high gas pressure

Disconnec t closed; blower and burner switches in run position;

winter

low gas normal

"; "

starter energized

"; "

Disconnec t closed; blower and burner switches in run position;

" lights are lit and the blower

low air

" and "

low air

", "

ht is not lit.

", "

" position; "

firestat normal

"; "

" and "

low air

", "

low air

", "

low air

", "

con trol power

freezestat normal

" lights are li t and the

high air

system sw itch

"; "

not

firestat

"firestat"

firestat

"firestat"

" are lit;

firestat

" and "

firestat

limit

", "

firestat

limit

", "

" and

high gas

", "

" lights are

1. Fuses are mi ssing or blown in disconnect switch - replace fuses.

lit.

2. Transformer not wired according to diagram - chec k wiring.

3. Secondary 8A fuse (on transforme r) is missing or blown - replace fuse.

4. Indicator light is burned out - replace bulb (P/N 125189).

1. See causes and remedies for Problem 1 above.

lit.

2. Optiona l control relay or door switch contacts are ope n - to test, jump terminals 3 to 4 or 1 to 2.

3. Firestat option not ordered - verify order/wi ring diagram.

4. Firestat manual reset tripped - reset firestat control.

1. Freezestat option not ordered - verify order/wiring diagram.

" light

2. Freezestat relay contacts are open - checking setting o n control.

3. Indicator bulb is burned out - replace bulb (P/N 125189).

1. End switch on damper motor not closed. - check end switch wiring.

" and

2. Faulty damper relay - replace relay.

3. Damper motor miswired - rewire damper mo tor per wiring diagram.

1. Blower motor not wired correctly - check wiring diagram on motor.

2. Faulty motor starter - replace (check coil first).

3. Faulty blower motor relay - replace relay.

1. Low air switch open - verify pressure drop a t burner.

2. Indicator light is burned out - replace bulb (P/N 125189).

3. Faulty low air switch - replace pressure switch (P/N 203932).

1. High air switch open - verify pressure drop at burner.

2. Indicator light is burned out - replace bulb (P/N 125189).

3. High air switch option not ordered - verify order/wiring diagram.

4. Fault y high air switch - re place pressure switch (P/N 203933).

1. Indicator light is burned out - replace bulb (P/N 125189).

2. Tripped manual reset limit control(s) - reset manual control.

3. Faulty manual limit control (s) - replace limit control.

1. Indicator light is burned out - replace bulb (P/N 125189).

limit

2. High ambient control option not ordered - verify order/wiring diagram.

3. High ambient control contacts open - chec k setting on control.

1. Indicator light is burned out - replace bulb (P/N 125189).

2. Low gas pressure switch option not ordered - verify order/wiring diagram.

hts

" li

3. Low gas pressure switch contacts open - check setting on control.

4. Low gas pressure switch contacts open - check gas pressure.

5. Faulty gas p ressure swit ch - repla ce gas pressure switch.

1. Indicator light is burned out - replace bulb (P/N 125189).

2. High gas pressure switch option not ordered - verify order/wiring diagram.

3. High gas pressure switch contacts open - check setting on control.

4. High gas pressure switch contacts open - c heck gas pressure.

5. Manual reset on switch tripped - reset pressure switch manual reset.

6. Faulty gas p ressure swit ch - repla ce gas pressure switch.

1. Lack of power at L1 on ignition module - ECO blown, find cause then lace ECO.

2. Faulty burner enable relay - replace relay.

3. Low stage relay contacts are not closed - check air co ntroller or thermostat

settin

4. Fault y low stage relay - replac e relay.

5. Faulty hot surface ignitor - check continuity at the ignition module and

circuit board. If readin

6. Faulty ignition module - replace entire module.

1. Ignitor not reaching 1.4A threshold - c heck voltage and current to ignitor.

2. Faulty hot surface ignitor - check continuity, replace ignitor.

3. Faulty ignition module - replace entire module.

is greater than 5-6 ohms, replace ignitor.

Form O-DV/RDF/ADF, P/N 148385, Page 21

OPERATION/SERVICE SECTION (cont'd)

20. Troubleshooting (cont'd)

Chart 1 - System Troubleshooting (Check the diagnostic lights.) (cont'd)

Symptom or Problem (cont’d) Cause an d Remedy (cont’d )

14.

Disconnect closed;

control sw itch is in "

normal energized

ignitor has reached 1.4A and has opened the pilot valve bring ing on the

pilot valve normal

" trials the unit will go into safety lockout requiring cycling of the main disconnect switch.)

15.

control sw itch is in " "main valve normal" light. The pilot f la me is present and stable, but the (low stage portion or) main gas valve will not open, or rapid cycling of the main valve is occur ring.

16.

control sw itch is in "winter" position; all status lights are lit; the pilot flame an d low fire on the main burner are presen t and stable, but the unit will not progress to a high f ire conditio n.

low gas normal

; "

starter energized

"; "

Disconnect closed;

Disconnect closed; blower and burner switches in run position;

blower

winter

"; "

" light; but the pilot flame is not present. (After two

blower

winter

burner

and

" positi o n; "

firestat normal

freezestat normal

" and "

burner

and

" positi o n;

all status lights are lit

switches in run position;

control power

"; "

switches in run position;

high gas

system switch

" lights are lit;

except

1. Air in pilot gas line - bleed pilot line.

2. Inadequate pilot gas pressure - verify pilot gas pressure (3.5" w.c.)

3. Faulty pilot valve - replace pilot solenoid valve.

4. Faulty ignition modu le - replace entire module.

1. Microamp signal on flame rod is inadequate - check position and

condi tion of flame rod and si

2. Grou nding for unit or flame rod inadequate - check ground path.

3. Faulty main gas valve - replace main gas valve.

4. Faulty ignition modu le - replace ignition module.

5. Inadequate main gas pressure - verify main burner pressure.

1. Faulty main gas valve - replace main gas valve.

2. Inadequate timing on high fire time delay relay - adjust setting.

3. Faulty high fire time delay r elay - replace time delay relay.

4. High stage relay contacts are no t closed - check control setting.

5. Inadequate main gas pressure - verify main burner gas pressure.

6. Faulty high stage relay - replace relay.

7. Faulty ignition modu le - replace entire module.

nal (minimum 0.5 micr oamps required.)

REFERENCE: For service and troubleshooting information on the electrical controls, refer to the manufacturer's literature covering that component. Component literature is included in the literature envelope.

Form O-DV/RDF/ADF, P/N 148385, Page 22

Chart 2 - Troubleshooting Optional Evaporative Cooling Module (Models ADF/ADFH)

grap

WARNING: Disconnect the power before servicing the cooling module. Failure to do so can cause electrical shock, personal injury or death.

Problem Probable Cause Remedy

Float & Pump Control System - Pump does not run. Unit is calling for cooling (i.e. console control switch is in cooling

osition) and reserv oir is full.

Float & Pump Contro l Sys tem Requir ed water level (3") not maintained

Water running off of media pads 1. Exc essive wa ter flow 1. Adjust ball valve in distribution line. See Maintenance Section,

Water not distributin

Media pads becoming clogged and discolored quickly (scale/salt deposits) and/or r apid deterioration of the float switch (Float and Pump Control S

stem)

Water blowoff from media 1. Media pads inst alled incorrectly 1. Instal l media pads correctly. See Maintenance Section , Paragraph 7. pads or water bei ng pulled from reservoi

evenl

1. Electrical connections 1. Verify all electrical connections. See Wiring Diagram.

2. Electric float switch on pump 2. Check position of the actuators on the electric float switch.

3. Dirty pump 3. Clean pump.

4. Defective pump 4. Replace pump.

1. Float valve 1. Adjust float valve. See Filling and Adjusting Water Level.

2. Optional dra in and fill valves 2. Check valve for proper operation.

3. Incorrect overflow pipe nipple - should be 3-1/2"

4. Drain leaking 4. Tighten dr ain plug.

2. Media

1. Distribution line clogged 1. Flush distributi on line. See Maintenance Section, Paragraph 7.

2. Holes in distribution line turned 2. Check position of distribution line. Holes shoul d be spraying upward.

3. Incorrect voltage to pump (Float & Pum

1. Bleed off line clogged 1. Clean bleed line.

2. Exc essive water flow 2. Reduce flow by adjusti ng ball valve in distribution line. See

3. Inadequate bleed off 3. A uniform build-up of minerals on the e ntering air fac e of t he media

2. Requires moisture elimination pad (over 600 FPM)

3. Water level not 3 inches (float & pump control system)

ads need cleaned or replaced. 2. Clean or replace media pads . See Main tenance Section , Paragraph 7.

control system)

3. Replace pipe nipple.

h 7.

Para

If not

ositioned with holes toward top, adjust position o f PVC line.

3. Check voltage at pump terminal in cooling module junction box.

Maintenance Section, Para

indicates insufficient bleed off. Increase the rate until the mineral de

ate.

dissi

2. Install moisture elimination pad. Consult factory.

3. See second problem listed above (Required water level not being maintained.)

h 7.

osits

Form O-DV/RDF/ADF, P/N 148385, Page 23

FOR SERVICE OR REPAIR, FOLLOW THESE STEPS IN ORDER:

FIRST: Contact the Installer

Name ______________________________________________________________ Address ______________________________________________________________

______________________________________________________________ ______________________________________________________________

Phone __________________________________________________

SECOND: Contact the nearest distributor (See Y ellow Pages). If no listing,

contact Authorized Factory Representative, 1-800-695-1901 (Press 1).

THIRD: Contact REZNOR®/Thomas & Betts Corporation

150 McKinley Avenue Mercer, PA 16137 Phone: (724) 662-4400

Model No. __________________________________________________

Unit Serial No. _______________________________________________

Date of Installation ____________________________________________

Form O-DV/RDF/ADF, P/N 148385, Page 24

(800) 695-1901 www.RezSpec.com

Trademark Note: Reznor® is registered in the United States and other countries. 8/03 YL POD Form O-DV/RDF/ADF

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