Components And Controls; Accumulator; Choke/Inductor; Coil Temperature Thermistor - Rheem P17 Series Installation Instructions Manual

7.1 Accumulator

All (-)P17 EcoNet™ heat pumps are equipped
with an accumulator for the purpose of managing
possible refrigerant flood back issues that may
occur at abnormal environmental conditions.

7.2 Choke/Inductor

The power inverter used in each (-)P17 model has
a paired choke/inductor. The choke is designed as
a low pass filter and increase inductance. By doing
this the input power can be more efficiently used
by the inverter and compressor.
7.3 Coil Temperature
Thermistor
(-)P17 heat pumps are equipped with a coil sensor
that is used for the purposes of identifying defrost
parameters and low ambient cooling operational
conditions. This thermistor is provided with the
suction line thermistor as a single harness.

7.4 Compressor

(-)P17 heat pumps are equipped with a Copeland
variable speed scroll compressor with a brushless
DC motor. The compressor is designed to work
in conjuction with the Power Inverter Compressor
Control and the Variable Speed Outdoor Control to
provide capacity modulation.
7.0 COMPONENTS & CONTROLS
7.5 Compressor Sump
Thermistor
(-)P17 heat pumps utilize a sump thermistor to
monitor the condition of the lower bearing in the
compressor sump. As environmental variables
change it is possible to have liquid refrigerant
flood back to the compressor. Although the (-)P17
designs have been specified to minimize this from
happening, occasions can occur where this may
happen. During these conditions, the EcoNet™
Variable Speed Outdoor Control has been
programmed to slow the compressor speed until
the liquid refrigerant exits the compressor shell.
The sump thermistor is also used to identify when
compressor stator heat is needed during off cycles
to warm the sump. See Section 8.4 for more
details on this operation.
7.6 Discharge Line
Thermistor
(-)P17 heat pumps are equipped with a discharge
line thermistor that is used to measure the
compressor discharge temperature. This sensor's
leads connect directly to the inverter which
communicates with the Variable Speed Outdoor
Control (VSODC). The compressor discharge
temperature is continuously monitored by the
controls. The compressor speed is reduced
as needed to prevent excessive discharge
temperatures that would damage the compressor
under extreme environmental conditions. As the
discharge temperature returns to an acceptable
level, the controls will gradually increase the
compressor speed in an attempt to meet the
capacity demand as long as the discharge
temperature remains at a safe level.
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