50A55-743
Integrated Furnace Control
INSTALLATION INSTRUCTIONS
FAILURETO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BEFORE INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL INJURY AND/OR PROPERTY DAMAGE.
DESCRIPTION
The 50A55-743 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.
These controls incorporate system fault analysis for quick gas flow shut-off, coupled with automatic ignition retry upon sensing a fault correction. It is designed as a replacement for the following controls:
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Goodman |
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White-Rodgers |
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0130F00005 |
PCBBF110 |
PCBBF123 |
50A55-743 |
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0130F00005S |
PCBBF110S |
PCBBF123S |
50A55-289 |
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B1809926 |
PCBBF112 |
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50T55-289 |
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B1809926S |
PCBBF112S |
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PRECAUTIONS
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.
Followinginstallationorreplacement,followmanufacturer’s recommended installation/service instructions to ensure proper operation.
! CAUTION
Donotshortoutterminalsongasvalveorprimary control. Short or incorrect wiring may damage the thermostat.
!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.
•Protectthecontrolfromdirectcontactwithwater
(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.
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.
www.white-rodgers.com |
PART NO. 37-7348A |
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www.emersonclimate.com |
1226 |
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
*MeasuredwithaDCmicroammeterintheflameprobelead
OPERATING TEMPERATURE RANGE:
-40° to 175°F (-40° to 80°C)
HUMIDITY RANGE:
5% to 93% relative humidity (non-condensing)
MOUNTING:
Surface mount multipoise |
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Timing Specs: (@ 60 Hz**) |
maximum |
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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, Liquified Petroleum, and LP Gas Air Mixtures are all approved for use.
TIMING SPECIFICATIONS
(All times are in seconds, unless noted otherwise
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50A55-743 |
Pre-Purge |
15 |
Initial Ignitor Warm-up |
7 |
(1st 64 attempts) |
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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 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.
Any orientation is acceptable.
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.
After installation or replacement, follow appliance manufacturer’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
Donotshortoutterminalsongasvalveorprimary 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.).
•Ifthecontrolhasbeenindirectcontactwithwater, 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.
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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WIRING
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TYPICAL SYSTEM WIRING DIAGRAM |
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HOT |
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NEUTRAL |
(LINE) |
120 VAC |
(LINE) |
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24 VAC CLASS II TRANSFORMER
TH |
24 VAC |
TR |
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50A55 |
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COOL |
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HEAT |
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CIRCULATOR |
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PARK |
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BLOWER |
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PARK |
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LINE |
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XFMR |
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EAC |
INDUCER |
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HUM |
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IND-N |
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IND |
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IGN |
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HUMIDIFIER |
IGN-N |
IGNITOR |
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CIR N |
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LINE N |
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XFMR N |
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ELECTRONIC |
HUM N |
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EAC N |
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AIR CLEANER |
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Y |
Y |
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W |
W |
COMPRESSOR |
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CONTACTOR |
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50A55 |
G |
G |
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in other |
R |
R |
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furnace(s) |
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— |
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THERMOSTAT |
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TWINNING |
C |
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APPLICATIONS |
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ONLY |
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TWIN* |
TWIN* |
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PRESSURE SWITCH (N. O.) |
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PS |
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PSO |
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HLI |
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FLAME |
HLO |
HIGH LIMIT |
AUX. HIGH |
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SENSOR |
FP |
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(N. C.) |
LIMIT (N. C.) |
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PROBE |
RO1 |
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ROLLOUT |
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GND |
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RO2 |
(N. C.) |
GAS |
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MV |
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VALVE |
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MV |
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TR |
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TH |
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LEGEND |
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Low Voltage (24 VAC) |
* The twinning feature is available only on models with |
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Line Voltage (120 VAC) |
six screw terminals; one of these terminals will be |
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designated “TWIN”. All 50A55 controls used in |
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N. C. = Normally closed switch |
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twinning applications must have the “TWIN” terminal. |
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N. O. = Normally open switch |
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