Trane ACONT900AC43UA Service Manual page 93

Charge Assist TM Troubleshooting
Troubleshooting the Charge Assist
Step 1
Is there 24 volts AC at the Charge Assist™ control at
plug J2 pins R and B (Figure 28)?
Figure 28
Yes: Go to Step 2 for a communicating system. For
a 24 volt AC control system, go to Step 4.
No: Restore the 24 volt AC power to the outdoor
unit.
Note: A communicating system the 24 volt AC is sup-
plied by the outdoor unit's transformer.
Note: A 24 volt AC control system the 24 volt A/C power
is supplied by the indoor unit's transformer.
Step 2
Is the Charge Assist™ control's COM LED (Figure 29)
flashing the correct number of times? Example: A sys-
tem that has a communicating thermostat, a commu-
nicating furnace or air handler and a communicating
outdoor unit the COM LED should be flashing in groups
of three flashes.
Figure 29
Yes:
ing with the control system. Go to Step 3.
TM
Control
No:
shooting ERR code 89 or 91 section.
Step 3
Is the Status LED (Figure 30) flashing slowly?
Figure 30
Yes:
No:
Status will not stop flashing fast, replace the Charge
Assist™ control.
Step 4
Does Y1 or Y2 LEDs (Figure 31) come on when a call
for compressor operation is placed at the comfort sen-
sor thermostat or the 24 volt A/C control thermostat?
Note: When the comfort sensor thermostat is set up
for compressor operation and WAIT is displayed on
the sensor display, there will be a five minute delay
before Y1 or Y2 will come on.
Note: A 24 volt A/C digital thermostat may have a time
delay when the cooling set point is changed to prevent
compressor short cycling.
Figure 31
Charge Assist™
The Charge Assist™ control is communicat-
The COM LED is flashing fast, go to the trouble
Go to Step 4.
If the Status LED is out, go to Step 5. If the
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