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Application Guidelines
8
AB141686422149en-US0401
Electrical data, connections and wiring
Supply Voltage
VRJ compressors must not be connected directly
to the mains supply. They must only be powered
through the dedicated Danfoss variable speed
drive.
Compressor model
Variable Speed Drive Model
VRJ028
176L0767
VRJ035
176L0766
VRJ044
176L0765
Nominal voltage
208-230V – 1Ph – 60Hz
Voltage range
187 – 253 V
Refer to “Danfoss VRJ Installation and Operation
instructions” for more details about supply
voltage.
Compressor electrical
specifications
Compressor model
LRA
MCC
Winding resistance
A
A
Ohm
VRJ028
10.2
18
0.296
VRJ035
12
23.5
0.254
VRJ044
12
30
0.254
LRA (Locked Rotor Amp)
MCC (Maximum Continuous
Current)
Winding resistance
LRA is the higher average current as measured
on a mechanically blocked compressor tested
under nominal voltage. LRA is printed on the
nameplate, according to UL requirements. With
VRJ compressors, the LRA value is low because the
variable speed drive reacts very rapidly (far below
1 second).
The MCC value is the maximum at which
the compressor can be operated in transient
conditions and out of the operating envelope. The
MCC value is measured based on UL conditions
(max load) and at low voltage.
VRJ scroll compressors are equipped with an IPM
(permanent magnet) motor.
Winding resistance is the resistance between
indicated terminal pins 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:
R
tamb
= R
77°F
a + t
amb
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
tamb
: winding resistance at t
amb
a: Coefficient a= 390
Содержание VRJ
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