Application guidelines
15
FRCC.PC.021.A5.22
Electrical data, connections and wiring
Compressor power supply
Operating Control System (OCS)
power supply
Winding resistance is the resistance between
phases at 77°F (resistance value +/- 7%).
Winding resistance is generally low and it
requires adapted tools for precise measurement.
Use a digital ohm-meter, a “4 wires” method and
measure under stabilised ambient temperature.
Winding resistance varies strongly with winding
temperature ; if the compressor is stabilised at a
different value than 77°F, the measured resistance
must be corrected with following formula:
a + t
amb
R
amb
= R
77°F
_________
a + t
77°F
t
77°F
: reference temperature = 77°F
t
amb
: temperature during measurement (°F)
R
77°F
: winding resistance at 77°F
R
amb
: winding resistance at tamb
Coefficient a = 234.5
Electrical supply is connected to the compressor
terminals by Ø 3/16" (4.8 mm) screws. The
maximum tightening torque is 2.2 ft.lb. Use a 1/4"
ring terminal on the power leads.
The compressor must be connected to earth with
the 0.20 inch earth terminal screw.
The Operating Control System (OCS) can
be supplied with 230V. For 230V OCS, earth
connection must be done with a 1/4" faston
terminal.
To avoid personal injury, earth continuity must
be checked before switching the power on.
Provide separate electrical supply for the OCS so
the heater remains energized when the machine
is out of service (eg.seasonnal shutdown).
Winding resistance
Nominal voltage
Voltage range
230V ~1 50/60Hz
207-254V ~1 50Hz - 180-254V ~1 60Hz
Wiring Connections
Danfoss Commercial Compressors
supply & connections
Customer supply or Danfoss
Commercial Compressors kit on
request
Customer supply & connections
CAN-Bus (if manifolded)
MYK / GRS
Modbus
DGT sensor
LP sensor
HP sensor
Liquid Injection Valve (LIV)
M1 M2 control circuit
Surface Sump Heater
OCS power supply
Cover holding screws (x4)
Torque: 2.2 Nm