Electrical data, connections and wiring
The temperature inside the terminal box may not
exceed 70°C. Consequently, if the compressor is
installed in an enclosure, precautions must be
taken to avoid that the temperature around the
compressor and in the terminal box would rise
too much. The installation of ventilation on the
enclosure panels may be necessary. If not, the
control board may not operate properly. Any
compressor damaged related to this will not
be covered by Danfoss warranty. In the same
manner, cables must be selected in a way to
insure that terminal box temperature does not
exceed 70°C.
The compressors models PSH019-023-026-030-
034-039 have been provided with an internal
overload protection to prevent against excessive
current and temperature caused by overloading,
low refrigerant flow or phase loss. The cutout
current is the MCC value listed before.
The protector is located in the star point of the
motor and, should it be activated, will cut out all
three phases. It will be reset automatically. While
not compulsory, an additional external overload
is still advisable for either alarm or manual reset.
Then it must be set below MCC value:
• When the motor temperature is too high, then
the internal protector will trip.
• When the current is too high the external
overload protection will trip before the internal
protection therefore offering possibility of
manual reset.
Use a phase meter to establish the phase
orders and connect line phased L1, L2 and L3
to terminals T1, T2 and T3, respectively. The
compressor will only operate properly in a single
direction, and the motor is wound so that if the
connection is correct, the rotation will also be
correct.
The compressor models PSH019-023-026-
030-034-039 incorporate an internal reverse
vent valve which will react in the presence of
reverse rotation and will allow refrigerant to
circulate through a by-pass from the suction
to the discharge. Although reverse rotation is
not destructive for these models, it should be
corrected as soon as possible. Reverse rotation
will be obvious to the user as soon as power
is turned on, the compressor will not build up
pressure, the sound level will be abnormally
high and power consumption will be minimal.
If reverse rotation symptoms occur, shut the
compressor down and connect the phases to
their proper terminals. If reverse rotation is not
halted, the compressor will cycle off on the motor
protection.
Terminal box
temperature
Terminal box knock-out
dimensions
Compressor protection
The terminal box is provided with a Ø 25.5 mm
knockout for main power supply and a sealed
hole for other wirings to control board.
Motor protection
Compressor model
Overheating protection
Over current protection
Locked rotor protection
Phase reversal protection
PSH019-023-026-030-034-039
Internal motor protection
Internal reverse vent valve
Phase sequence and reverse
rotation protection
15
FRCC.PC.022.A4.02
Application Guidelines
