Document No.: CL232 issue F
Page No. 5 of 15
NEVER apply 240V across thermistor terminals. Maximum test Voltage = 3V.
The thermistor control module is a “Fail-Safe” design. The control contact opens when power
to the module is cut, and closes when power is returned only if the thermistors signal correct
operating conditions. The thermistors should never be disconnected from the module, and
the module should never be bypassed, when the unit is in operation.
In addition to the above, thermal over-current protection is fitted to the compressor contactor(s), and
MP15 PhaseFale phase failure protection is available, on three phase compressors only.Please
contact your Heatcraft sales representative for details.
The MP15 start delay function has been utilised as follows-
HP/LP alarm to pin 5- delay with memory function and light
Compressor contactor K1 Thermal Overload N/O 97-98 to pin 8 (start delay without
memory or light).
Compressor restart will be delayed by 15 minutes when activated by these 2 fault conditions.
Restarting the MP15 (toggle Circuit Breaker CB1 Off/On) will re-initialize the MP15 timer.
Caution – Internal Pressure Relief (IPR) Valve
Some hermetic compressors include an IPR valve. The IPR valve will open when the discharge
pressure exceeds the suction pressure by a certain value which is set by the compressor
manufacturer. When it has opened, the compressor sump will become warm and the compressor will
trip out on the motor protector. The unit may take 2 to 3 hours to reset and restart automatically if this
happens.
Kulthorn Kirby “AW” and Danfoss “Maneurop” compressors have an IPR valve.
Dorin compressors do NOT have an IPR valve.
Do NOT assume that a compressor that is running, but not pumping, is faulty.
Stop the compressor and allow the pressures to balance, then start the compressor again.
Purpose
PolarPack condensing units are standard OEM products of Heatcraft Australia including both
“medium” and “low” temperature application ranges. They are designed for continuously supplying
and receiving the refrigerant to and from the evaporator(s), and rejecting the heat extracted from the
cold space to surrounding atmosphere where the units are installed.
PolarPack condensing units are intended for installing in a typical ventilated indoor or outdoor
environment (Refer to the General Arrangement Drawing section for details) with the condensing
temperature no greater than 60°C and compressor return vapour temperature no greater than 20°C.
They are not intended for environments that may have harmful, corrosive or flammable atmospheres.
Marine environments are considered corrosive; please consult Heatcraft before installing in this
environment.
Standard Design Conditions
Medium temperature range condensing units are typically designed, for primary refrigerant R404A, to
be used in commercial cool room applications ranging from -20°C to +10°C saturated suction
temperature for Kulthorn Kirby compressors, -25°C to +5°C for Maneurop compressors, and –35°C
to +5°C for Dorin compressors. R507/R404A and R22 are recommended refrigerants. For R134a
usage, please refer to other sections of this booklet for control setting information etc.
Low temperature range condensing units are designed, for primary refrigerant R404A, to be used in
commercial freezer room applications ranging from -35°C to -15°C saturated suction temperature for
Kulthorn Kirby, and -40°C to -20°C for Maneurop compressors. R507 or R404A are the
recommended refrigerants.
Please refer to sales data sheet CL225 for standard PolarPack condensing unit configurations,
options offered and other detailed information such as capacity variations for other refrigerants.
For special design requirements (non standard conditions and/or refrigerants), please inquire
with your local representatives and/or Heatcraft Australia local branches, or call our national
telephone number 13 23 50 for your nearest available information resources.
