White Rodgers 50A55-438 User Manual

50A55-438

WHITE-RODGERS

Operator: Save these instructions for future use!

FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL INJURY AND/OR PROPERTY DAMAGE.

The 50A55-438 is an automatic gas interrupted ignition control that employs a microprocessor to continually monitor, analyze, and control the proper operation of the gas burner, inducer, and fan.

Signals interpreted during continual surveillance of the thermostat and flame sensing element initiate automatic ignition of the burner, sensing of the flame, and system shut-off during normal operation.

Installation should be done by a qualified heating and air conditioning contractor or licensed electrician.

If in doubt about whether your wiring is millivolt, line, or low voltage, have it inspected by a qualified heating and air conditioning contractor or licensed electrician.

Do not exceed the specification ratings. All wiring must conform to local and national electrical codes and

ordinances. This control is a precision instrument, and should be handled

carefully. Rough handling or distorting components could cause the control to malfunction.

Following installation or replacement, follow manufacturer’s recommended installation/service instructions to ensure proper operation.

CAUTION

Do not short out terminals on gas valve or primary control. Short or incorrect wiring may damage the thermostat.

Integrated Furnace Control

INST ALLA TION INSTRUCTIONS

DESCRIPTION

These controls incorporate system fault analysis for quick gas flow shut-off, coupled with automatic ignition retry upon sensing a fault correction.

PRECAUTIONS

WARNING

Failure to comply with the following warnings could result in personal injury or property damage.

FIRE HAZARD

• Do not exceed the specified voltage.

• Replace existing control with exact model and dash number.

• Protect the control from direct contact with water (dripping, spraying, rain, etc.).

• If the control has been in direct contact with water, replace the control.

• Label all wires before disconnection when servicing controls. Wiring errors can cause improper and dangerous operation.

• Route and secure wiring away from flame.

CONTENTS

Description............................................................. 1

Precautions............................................................ 1

Specifications.........................................................2

Installation..............................................................3

Mounting & Wiring

Operation ............................................................... 6

Mounting Hole Template........................................8

WHITE-RODGERS DIVISION

EMERSON ELECTRIC CO. 9797 REAVIS ROAD ST. LOUIS, MISSOURI 63123-5398

Printed in U.S.A.

SHOCK HAZARD

• Disconnect electric power before servicing.

• Ensure proper earth grounding of appliance.

• Ensure proper connection of line neutral and line hot wires.

EXPLOSION HAZARD

• Shut off main gas to appliance until installation is complete.

PART NO. 37-6102B

Replaces 37-6102A

0009

SPECIFICATIONS

ELECTRICAL RATINGS [@ 77°F (25°C)]:

Input Voltage: 25 VAC, 50/60 Hz Max. Input Current @ 25 VAC: 0.45 amp

Relay Load Ratings:

Valve Relay: 1.5 amp @ 25 VAC, 50/60 Hz, 0.6 pf Ignitor Relay: 6.0 amp @120 VAC, 50/60 Hz, (resistive)

Flame Current Requirements:

Minimum current to insure flame detection: 1 µa DC* Maximum current for non-detection: 0.1 µa DC* Maximum allowable leakage resistance: 100 M ohms

*Measured with a DC microammeter in the flame probe lead

OPERATING TEMPERATURE RANGE:

-40° to 175°F (-40° to 80°C)

HUMIDITY RANGE:

5% to 93% relative humidity (non-condensing)

MOUNTING:

Surface mount multipoise

TIMING SPECS: (@ 60 Hz**)

maximum

Flame Establishing Time: 0.8 sec Flame Failure Response Time: 2.0 sec

** At 50 Hz, all timing specifications should be increased by

20%.

Gases Approved: Natural, Manufactured, Mixed, Liquefied

Petroleum, and LP Gas Air Mixtures are all approved for use.

TIMING SPECIFICATIONS

(All times are in seconds, unless noted otherwise)

50A55-438

PRE-PURGE TRIAL FOR IGNITION

PERIOD IGNITION ACTIVATION

PERIOD RETRIES VALVE SEQUENCE

PERIOD INTERPURGE POST-PURGE LOCKOUT TIME DELAY TO HEAT ON

DELAY TO HEAT OFF DELAY TO COOL ON

DELAY TO COOL OFF MINIMUM IGNITOR

WARM-UP MAXIMUM IGNITOR

WARM-UP INITIAL IGNITOR WARM-

UP (1st 64 attempts) HUMIDIFIER ELECTRONIC AIR

CLEANER

* These times will vary depending on option switch position.

The control is factory-set at 0 sec. delay to cool off and 100 sec. delay to heat off. See OPERATION section for further information.

0 4

2 times

12 60

300

60/100/

140/180*

0/80*

YES YES

WARNING

FIRE HAZARD

• Do not exceed the specified voltage.

• Replace existing control with exact model and dash number.

• Protect the control from direct contact with water (dripping, spraying, rain, etc.).

• Label all wires before disconnection when servicing controls. Wiring errors can cause improper and dangerous operation.

• Route and secure wiring away from flame.

SHOCK HAZARD

• Disconnect electric power before servicing.

• Ensure proper earth grounding of appliance.

• Ensure proper connection of line neutral and line hot wires.

EXPLOSION HAZARD

• Shut off main gas to appliance until installation is complete.

CAUTION

Do not short out terminals on gas valve or primary control. Short or incorrect wiring may damage the thermostat.

INSTALLATION

MOUNTING AND WIRING

All wiring should be installed according to local and national electrical codes and ordinances.

The control must be secured to an area that will experience a minimum of vibration and remain below the maximum ambient temperature rating of 175°F. The control is approved for minimum ambient temperatures of -40°F.

When mounting the control, any orientation is acceptable. Choose a location that will not damage, obstruct or place stress on the control’s terminations, system wiring harness or system components. After finding a suitable location, drill four (4) 1⁄8” holes for mounting control. To ensure proper mounting hole locations, there is a mounting hole template on page 8 of this instruction sheet. Detach the page with the template from the instruction sheet and apply it to the mounting location. When drilling the holes, take care so that the transformer, wiring harness or other system components are not damaged. Four (4) #8 sheet metal screws are provided to complete the installation.

Refer to the wiring diagram and wiring table when connecting the 50A55 control to other components of the system.

UL approved, 105°C rated 18 gauge, stranded, 2⁄64” thick insulation wire is recommended for all low voltage safety circuit connections. Refer to 50A55 specification sheet for recommended terminals to mate with those on the control.

UL approved, 105°C rated 16 gauge min., stranded, 4⁄64” thick insulation wire is recommended for all line voltage connections. Refer to 50A55 specification sheet for recommended terminals to mate with those on the control.

The 50A55 has only one serviceable part–an automotive type fuse, which protects the low voltage transformer from damage if its output is short-circuited. If the fuse has opened up, remove whatever caused the short circuit and replace the fuse with only a 3 Amp automotive type fuse. If the fuse is not the cause of the control’s problem, replace the entire 50A55 control. There are no other user serviceable parts.

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