Carrier 59SC2A - Page 66

59SC2A
SERVICE sis
If status code recall is needed, briefly remove then reconnect one main
limit wire to display last stored status code. After one status code recall is
completed component test will occur.
LED CODE STATUS
CONTINUOUS OFF = Check for 1745VAC at L1 & L2, & 24VAC at SEC-1 & SEC-2,
CONTINUOUS ON- Control has 24VAC power.
RAPID FLASHING - Line voltage (115VAC) polarity reversed. If twinned,
refer to twinning kit instructions.
EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST DIGIT DETERMINED
BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY THE NUMBER OF LONG FLASHES.
14 NO PREVIOUS CODE - Stored status codes are erased automatically after 72 hours.
{2 BLOWER ON AFTER POWER UP (115VAC or 24VAC) » Blower runs for 90 seconds, if unit is powered
up during a call for heat (R-W closed) or R-W opens during blower on-delay.
13 LIMIT CIRCUIT LOCKOUT = Lockout occurs if a limit or flame rollout switch is open longer than 3 minutes.
- Control will auto reset after three hours. ~ Refer to #33
14 IGNITION LOCKOUT + Control will auto-reset after three hours, Refer to #34,
21 GAS HEATING LOCKOUT - Control will NOT auto reset. Check for:
- Mis-wired gas valve - Defective control (valve relay)
22 ABNORMAL FLAME-PROVING SIGNAL « Flame is proved while gas valve is de-energized.
Inducer will run until fault is cleared. Check for: - Leaky gas valve - Stuck-open gas valve
23 PRESSURE SWITCH DID NOT OPEN + Check for: -Obstructed pressure tubing
- Pressure switch stuck closed
24 SECONDARY VOLTAGE FUSE IS OPEN « Check for: - Short circuit in secondary voltage (24VAC) wiring,
31 PRESSURE SWITCH DID NOT CLOSE OR REOPENED -If LPS open longer than five minutes, inducer
shuts off for 15 minutes before retry. If HPS remains open for one minute after gas valve closes
(after three succesive trials), then furnace control will lockout for 3 hours before retry. Check for:
- Excessive wind -Restricted vent —- Defective inducer motor
~ Low inlet gas pressure (if LGPS used) - Defective pressure switch
- Low inducer voltage (115VAC} - Inadequate combustion air supply
- Proper vent sizing - Disconnected or obstructed pressure tubing
- Condensate drainage restricted or blocked
If it opens during blower on-delay period, blower will come on for the selected blower off-delay.
33 LIMIT CIRCUIT FAULT - Indicates a limit or flame rollout, switch is open. Blower will run for 4 minutes
or until open switch remakes whichever is longer. If open longer than 3 minutes, code changes to
lockout #43. If open less than 3 minutes status code #33 continues to flash until blower shuts off.
Flame rollout switch requires manual reset. Check for: —- Dirty filter or restricted duct system
- Proper vent sizing - Restricted vent —- Loose blower wheel - Excessive wind
- Defective blower motor or capacitor - Defective switch or connections
- Inadequate combustion air supply (Flame Roll-out Switch open).
34 IGNITION PROVING FAILURE - Control will try three more times before lock out #14 occurs.
If flame signal lost during blower on-delay period, blower will come on for the selected blower
off-delay. Check for: = Oxide buildup on flame sensor (clean with fine steel wool)
- Proper flame sense microamps (.5 microamps D.C. min., 4.0 - 6.0 nominal)
- Manual valve shut-off - Control ground continuity - Gas valve defective or gas valve turned off
- Low inlet gas pressure - Inadequate flame carryover or rough ignition - Defective Hot Surface Iynitor
- Flame sensor must not be grounded — - Green/yellow wire MUST be connected to furnace sheet metal
45 CONTROL CIRCUITRY LOCKOUT = Auto-reset after one hour lockout due to; - Gas valve relay stuck open
- Flame sense circuit failure - Software check error
Reset power to clear lockout. Replace control if status code repeats.
COMPONENT TEST [aE
To initiate the component test sequence shut OFF the room thermostat or disconnect the
“R’ thermostat lead. Briefly short the TEST/TWIN terminal to the “Com 24V” terminal.
. Status LED will flash last status code and then turn ON the inducer motor. The inducer
+ : motor will run for the entire component test. The hot surface ignitor, blower motor FAN
; speed (if equiped) blower motor HEAT speed, and blower motor COOL speed will be
turned ON for 10-15 seconds each. Gas Valve and Humidifier will not be turned on.
338309-201 Rev.E
Fig. 56 - Service Label Information
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