Vogt P118F/HE100, Service Manual

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05TA Service Manual
SERVICE OPERATIONS
7/24/13
9-12
Sentronic Oil Pressure Safety Control
(4D & 6D compressors before March 2011).
All Sentronics utilize a pressure sensor and an electronic control module to precisely measure oil
pump differential pressure. The main advantage of Sentronic is the elimination of the traditional
capillary tubes, bellows, and pressure connections that mechanical pressure switches require to
measure differential oil pressure. These require careful handling and are known to be a source of
leaks in refrigeration systems.
A second advantage of Sentronic is in the use of a precise electronic clock for the two minute time
out circuit. Traditional mechanical controls use resistance heaters to provide the time to trip in the
event of low oil pressure. 208 volt systems, low ambient temperatures or brown-out type conditions
cause the heater output to be reduced, thus increasing the time out period from two minutes to three
or four minutes when low oil pressure conditions exist. With the electronic clock, the time out will
always be the same.
As a result of the elimination of the capillary tube measuring system and a more precise timing
circuit, Sentronic will improve the overall reliability of the refrigeration system. As in the past, all
new and replacement Copelametic compressors equipped with oil pumps require the use of a
Copeland approved oil pressure safety switch. Failure to use an approved oil pressure safety switch
will be considered as misuse of the compressor, and can adversely affect warranty replacement of
the compressor should a lubrication connected failure occur.
FIGURE 9-11
Sentronic Oil Pressure Safety Control
Sentronic Oil Safety (Sensor Only)
Part #: 12A2117A0501
Sentronic Oil Safety Control (Entire Unit)
Part #: 12A2117A05
Oil Sightglass (4D compressor)
Note: Sightglass on other side
of 3D compressors
Oil Pump
Module
Sensor
Copper
Washer
Reset Button