Carrier Infinity 25VNA8 Installation Instructions Manual page 18

Suction Thermistor (OST)
Suction Thermistor is used for assisting in EXV control and must
be secured on the suction tube and aligned longitudinally to the
vertical surface of the tube axis (see Fig. 25).
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
In order to minimize the ambient influence, make sure the
thermistor curved surface hugs the pipe surface and is
secured tight using the wire tie fished through the original
slot insulating polymer body.
Fig. 25 - - Suction Thermistor (OST) Attachment
(On Suction Tube)
Discharge Thermistor (ODT)
Discharge Thermistor is used for protection against over
temperature of the compressor.
compressor discharge stub- -out (see Fig. 26).
Fig. 26 - Discharge Thermistor (ODT)
A14023
The ODT is located on the
A14024
Variable Speed Compressor Power Input Terminals
This compressor operates with a 3- -phase variable frequency PWM
variable voltage to the three fusite terminals.
Table 6 – Variable Speed Compressor Resistance
(winding resistance at 70_F 20_F)
WINDING
24
Between terminals 0.59
T1, T2, and T3 OHM
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.
Fan Motor
If verification of proper operation is required for the fan motor
used in this unit, follow these steps:
1. Disconnect fan motor connector from control board.
2. Measure resistance between any 2 of the 3 leads present.
3. Compare measurement to values below
Fan Motor Resistance
Unit Size
24, 25, 36, 48
18
MODEL 25VNA8
25 36 48
0.59 0.59 0.37
OHM OHM OHM
>1 mega OHM
Resistance (Ohms)
11.1