White Rodgers 50A55-743 Specifications, Installation, Mounting and Wiring

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)

Inducer Relay: 2.2 FLA–3.5 LRA @ 120 VAC

Circulator Relay: 14.5 FLA–25.0 LRA @ 120 VAC

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

TIMING SPECIFICATIONS

(All times are in seconds, unless noted otherwise

	50A55-743
Pre-Purge	15
Initial Ignitor Warm-up	7
(1st 64 attempts)
Minimum Ignitor Warm-up	5
Maximum Ignitor Warm-up	9
Ignition Activation Period	2
Trial for Ignition Period	4
Retries	2 times
Valve Sequence Period	12
Interpurge	30
Post-Purge	15
Lockout Time	300
Heat Delay-To-Fan-On	30
Heat Delay-To-Fan-Off*	90/120/150/180
Cool Delay-To-Fan-On	5
Cool Delay-To-Fan-Off	45
Auto Reset	60 minutes
Humidifier	Yes
Electronic Air Cleaner	Yes

*These times will vary depending on option switch position. See OPERATION section for further information

INSTALLATION

MOUNTING AND WIRING

All wiring should be installed according to local and na- tional 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 ap- proved for minimum ambient temperatures of -40°F.

Any orientation is acceptable.

Refer to the wiring diagram and wiring table when connect- ing 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 rec- ommended terminals to mate with those on the control.

After installation or replacement, follow appliance manu- facturer’s recommended installation or service instructions to ensure proper operation.

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.

!CAUTION

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

!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.).

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

•Label all wires before disconnection when servic- ing 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.

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