83
Table 81 — Gas Heating Service Analysis
Table 82 — Electric Heat Service Analysis
PROBLEM CAUSE
REMEDY
Burners Will Not Ignite.
Active alarm.
Check active alarms using
Comfort
Link scrolling
marquee.
No power to unit.
Check power supply, fuses, wiring, and circuit breakers.
No power to IGC (Integrated Gas Control).
Check fuses and plugs.
Heaters off due to time guard to prevent short
cycling.
Check using
Comfort
Link scrolling marquee.
Control calling for Cooling.
Check using
Comfort
Link scrolling marquee.
No gas at main burners.
Check gas line for air and purge as necessary. After purg-
ing gas line of air, allow gas to dissipate for at least 5 min-
utes before attempting to re-light unit.
Water in gas line.
Drain water and install drip.
Inadequate Heating.
Dirty air filters.
Replace air filters.
Gas input too low.
Check gas pressure at manifold. Refer to gas valve adjust-
ment in Installation, Start-up, and Service Manual.
Control calling for W1only (low heat).
Allow time for W2 to energize.
Unit undersized for load.
Decrease load.
Restricted airflow.
Remove restriction.
Too much outdoor air.
Check economizer position and configuration. Adjust mini-
mum position using
Comfort
Link scrolling marquee
.
Limit switch cycles main burners.
Check rotation of blower, thermostat heat anticipator set-
tings, and temperature rise of unit. Adjust as needed.
Poor Flame Characteristics.
Incomplete combustion (lack of combustion air)
results in: Aldehyde odors, CO, sooting flame, or
floating flame.
Check all screws around flue outlets and burner compart-
ment. Tighten as necessary.
Cracked heat exchanger, replace.
Unit is over-fired, reduce input. Adjust gas line or manifold
pressure.
Check vent for restriction. Clean as necessary.
Check orifice to burner alignment.
Burners Will Not Turn Off.
Unit is in minimum on-time.
Check using
Comfort
Link scrolling marquee.
Unit running in Service Test mode.
Check using
Comfort
Link scrolling marquee.
PROBLEM CAUSE
REMEDY
No Heat.
Power failure.
Call power company.
Fuse blown or circuit breaker tripped.
Replace fuse or reset circuit breaker.
Thermostat occupancy schedule setpoint not call-
ing for Heating.
Check using
Comfort
Link scrolling marquee.
No 24 vac at primary contactor.
Check transformer and circuit breaker.
No power (high voltage) to L2 of primary contactor. Check safety switches “one-shot” backup and auto limit.
Bad electrical elements.
Power off unit and remove high voltage wires. Check resis-
tance of heater, replace if open.
Summary of Contents for Carrier Weathermaker 48A2
Page 105: ...105 Fig 20 Typical Main Control Box Wiring Schematic 48 50A2 A3 A4 A5 Units...
Page 106: ...106 Fig 21 Typical Auxiliary Control Box Wiring Schematic...
Page 107: ...107 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown a48 8357...
Page 108: ...108 TO NEXT PAGE Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown A48 7296...
Page 109: ...109 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont A48 8358...
Page 110: ...110 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown a50 8228...
Page 111: ...111 Fig 25 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown...
Page 112: ...112 Fig 26 Typical Low Ambient Controls Option Wiring...
Page 113: ...113 Fig 27 Typical Small Chassis Component Location Size 020 035 Units...
Page 114: ...114 Fig 28 Typical Large Chassis Component Locations Size 040 060 Units...
Page 118: ...118 Fig 30 Economizer Control Board ECB1 and VAV Control Board ECB2 A48 7706...
Page 142: ...142 A48 3733 Fig 56 Main Burner Removal...
Page 176: ...176 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716...
