Variable Speed Compressor Winding Resistance - Carrier EVOLUTION 189BNV Service Manual

Variable Speed Compressor Winding Resistance

This compressor operates with 3- -phase variable frequency PWM
variable voltage. For troubleshooting certain fault codes related to
compressor resistances, follow these steps:
1. Disconnect compressor power leads from the inverter MOC
terminals, U (YEL), V (RED), and W (BLK).
2. Measure the resistance between YEL to RED, YEL to BLK,
and RED to BLK and compare to Table 4 values. Each
resistance set should be equal.
3. Measure the resistance to ground for each lead.
4. If the resistances check out, reconnect power leads to
appropriate terminal.
5. If the resistances appear to be abnormal, it will be necessary
to measure the resistance at the compressor fusite terminals.
6. During the removal of the compressor fusite cap, do not re-
move the RTV sealant. Remove the harness plug, measure
the resistances, and compare to Table 4.
7. Special care will need to be taken with the replacement of
the compressor fusite cap. Make sure the two holes in the
compressor fusite terminal box are still full of RTV sealant
before the cap is reinstalled. The factory RTV can be reused
as long as none of it has been removed during the cap
removal.
8. Reinstall compressor sound blanket making sure discharge
thermistor and compressor power harness are routed as they
were from the factory
Fig. 35 – Variable Speed Control Board with optional Utility Relay
Utility Relay
Table 4—Variable Speed Compressor Resistance
(winding resistance at 70_F 20_F)
WINDING
13, 24B
Between
1.13
terminals
Between
terminal &
ground
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
Do not use Meggar for measuring the winding resistance.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
To maintain water integrity of the compressor fusite terminal
box, the two holes in outer ring need to be full of RTV sealant.
15
MODEL 288BNV / 189BNV (OHMs)
25 36 37, 48
.59 .59 .37
>1 mega
A13414
49, 60
.24