60
Table 46 — Economizer Service Analysis
LEGEND
Heating Troubleshooting —
Use the unit Scrolling
Marquee display or a CCN device to view the heating status
display and the heating diagnostic display (see Appendix A)
for information on the heating operation. Check the current
alarms and alarm history for any heating alarm codes and
correct any causes (see Table 44). Verify any unique control
configurations per installed site requirements or accessories. If
alarms conditions are corrected and cleared, operation of the
heat stages and indoor fan may be verified by using the Service
Test mode (see page 36 and Table 36).
GAS HEAT (48PG UNITS) — See Table 47 for general gas
heating service analysis. See Fig. 12 for service analysis of the
IGC board logic. Check the status LED on the IGC board for
any flashing alarm codes and correct any causes (see Table 48).
ELECTRIC HEAT (50PG UNITS) — See Table 49 for elec-
tric heating service analysis.
Phase Loss Protection —
The phase loss protection
option will monitor the three-phase electrical system to provide
phase reversal and phase loss protection.
PHASE REVERSAL PROTECTION — If the control sens-
es an incorrect phase relationship, the relay (K1) will be de-
energized (opening its contact). If the phase relationship is
correct, the relay will be energized. The control has a self-
bypass function after a pre-set time. If the control determines
that the three phases stay in a correct relationship for 10 con-
secutive minutes, the relay will stay energized regardless of the
phase sequence of three inputs as long as 24-vac control
voltage is applied. This self-bypass function will be reset if all
three phases are restored in a phase loss event.
PHASE LOSS PROTECTION — If the reverse rotation
board senses any one of the three phase inputs has no AC volt-
age, the relay will be deenergized (opening its contact). This
protection is always active as long as 24-vac control voltage is
applied, and is not affected by the self by-pass function of the
phase sequence monitoring function. However, in the event of
phase loss, the relay will be re-energized only if all three phases
are restored and the three phases are in the correct sequence.
PROBLEM
POSSIBLE CAUSE
REMEDY
Damper Does Not Move.
Indoor Fan is off.
Check for proper thermostat connection.
Unit is not configured for continuous fan
operation and the thermostat is not calling for
heating or cooling.
Unit is in Unoccupied mode and there is no
call for heating or cooling.
Tripped circuit breaker.
No power to the unit.
Unit is off via CCN command.
Actuator is unplugged at motor or at
economizer board.
Check wiring connections.
Unit is not configured for economizer.
Configure unit for economizer per the
instructions.
Outdoor-air temperature is above economizer
high temperature lockout.
Adjust the high temperature lockout setting
if it is incorrect, otherwise, economizer is
operating correctly.
Outdoor-air temperature is below economizer
low temperature lockout.
Adjust the low temperature lockout setting
if it is incorrect, otherwise, economizer is
operating correctly.
Communication loss to economizer board.
Check wiring connections.
Damper is jammed.
Identify the obstruction and safely remove.
Economizer Operation is Limited
to Minimum Position.
Minimum position is set incorrectly.
Adjust minimum position setting.
Outdoor-air temperature is above economizer
high temperature lockout.
Adjust the high temperature lockout setting
if it is incorrect, otherwise, economizer is
operating correctly.
Outdoor-air temperature is below economizer
low temperature lockout.
Adjust the low temperature lockout setting
if it is incorrect, otherwise, economizer is
operating correctly.
Outdoor-air thermistor is faulty.
Replace outdoor-air thermistor.
Low suction pressure problem with a compressor.
Economizer is operating correctly, identify
compressor problem.
Economizer Position is Less
Than Minimum Position.
IAQ is controlling minimum damper position.
Adjust the IAQ settings if incorrect,
otherwise, the economizer is operating correctly.
Unit is in Unoccupied mode.
Adjust unit occupied schedule if incorrect,
otherwise, economizer is operating correctly.
Economizer Does Not Return
to Minimum Position.
Unit is operating under free cooling.
Economizer is operating correctly.
Damper Does Not Close on
Power Loss.
Damper is jammed.
Identify the obstruction and safely remove.
Outdoor Damper Does Not Fully
Close at 0% or Fully Open at 100%.
Economizer actuator is out of calibration.
Enter Service Test mode and run the Calibrate
Economizer (E.CAL) procedure.
CCN — Carrier Comfort Network®
IAQ
— Indoor Air Quality
Summary of Contents for 48PG24
Page 68: ...68 Fig 14 Low Voltage Control Schematic 48PG20 28 Units without Humidi MiZer System a48 7627...
Page 69: ...69 Fig 15 Low Voltage Control Schematic 48PG20 28 Units with Humidi MiZer System a48 8227...
Page 70: ...70 Fig 16 Low Voltage Control Schematic 50PG20 28 Units without Humidi MiZer System a48 7778...
Page 71: ...71 Fig 17 Low Voltage Control Schematic 50PG20 28 Units with Humidi MiZer System a50 8101...
Page 72: ...72 Fig 18 Power Schematic Units without Humidi MiZer System a48 7628...
Page 73: ...73 Fig 19 Power Schematic Units with Humidi MiZer System a48 8228...
Page 74: ...74 Fig 20 Component Arrangement Units without Humidi MiZer System a48 8229...
Page 75: ...75 Fig 21 Component Arrangement Units with Humidi MiZer System a48 8230...
Page 105: ......