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© Danfoss | Climate Solutions | 2023.06
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Electrical connection
7.10 Oil sump heater (accessories)
Anschlussschema für Ölsumpfheizung
Connection diagramm for oil sump heater
Plan de raccordement pour résistance de carter d‘huile
09983- 10.01-DGBF
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When the compressor is at a standstill, refrigerant diffuses into the lubricating oil of the compressors
housing, depending on pressure and ambient temperature. This reduces the lubricating capacity of
the oil. When the compressor starts up, the refrigerant contained in the oil evaporates out throught the
reduction in pressure. The consequences can be foaming and migration of the oil, causing oil shocks
under certain circumstances.
Operation:
The oil sump heater operates when the compressor is at a standstill. When the compres
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sor starts up, the oil sump heater switches off again automatically.
Connection:
The oil sump heater must be connected via an auxiliary contact (or parallel wired auxili
-
ary contact) of the compressor contactor to a seperate electric circuit.
El. data: 230 V - 1 - 50/60 Hz, 160 W.
Fig. 16
ATTENTION
Connection to the current path of the safety control chain is not
permitted.
7.11 Oil sump heater at HC and LG compressors
As the solubility of hydrocarbons and HFO refrigerants in oil can be very high, especially at high
suction pressures, the compressor must be equipped with an oil sump heater. For this reason, a
pump-down circuit is recommended during standstill to reduce the suction-side standstill pressures.
ATTENTION The oil sump heater must generally be connected and operated!
• In a TT- or TN system, a residual current protection device (RCD)
must be used
.
•
In an IT system, an insulation monitoring device must be used.
National standards and regulations must be observed.
