Service Manual

SERVICE MANUAL (C,H,T)VA9 & (C,H,T)VH8
421 08 5600 02 5
Specifications subject to change wi thout notice.
A14302
Fig. 2 – HP Outdoor Coil Thermistor (OCT) Attachment
(On Distributor Tube)
A14328
Fig. 3 – AC Outdoor Coil Thermis tor (OCT) Attachment
(On Distributor Tube)
OAT Thermistor must be locked in place with
spherical nib end facing towards the front of
the control box
A11142
Fig. 4 – OAT Thermistor Location (Bottom of Control
Box)
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. 5).
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.
A14023
Fig. 5 – Suction Thermistor (OST) Attachment
(On Suction Tube)
Discharge Thermistor
(ODT)
Discharge Thermistor is used for protection against over
temperature of the compressor. The ODT is located on the
compressor discharge stub- out (see Fig. 6).
A14024
Fig. 6 – Discharge Thermistor (ODT)
Crankcase Heater
Operation
This unit has an internal crankcase heater that will be
energized during the off cycle and is intelligently demanded
by the system to prevent the compressor from being the
coldest part of the system thus enhancing the reliability.
The crankcase heater will function as needed any time the
outdoor unit is powered. The indoor unit and UI do not need
to be installed for the crankcase heater to operate properly.
The compressor windings will occasionally be energized
during the OFF cycle (depending on the length of the OFF
cycle) to start the stator heat operation, thus maintaining a
sump temperature that is essential for compressor reliability.
The compressor will not run during this process.