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SECTION 18 - OIL PUMP VARIABLE SPEED DRIVE
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
18
OIL HEATER OPERATION
On chillers equipped with the Oil Pump VSD, the Oil
Heater is controlled by the microboard via I/O Board
The connection to the I/O Board is determined by the
chiller style and compressor type as follows:
• TB1-34 - Style D and E chillers with G, H or J
compressors
• TB1-64 - Style E chillers with P compressors and
all Style "F" (and later) chillers
When the oil pump is not operating, the heater is turned
ON and OFF to maintain a target value of 50°F above
the Condenser Saturation Temperature. If the calculat-
ed target value is greater than 160°F, the target value
defaults to 160°F. If the calculated target value is less
than 110°F, it defaults to 110°F. When the temperature
decreases to 4°F below the target value, the heater is
turned ON; it is turned OFF at 3°F above the target.
To prevent overheating the oil in the event of an Op-
tiView Control Center failure, thermostat 1HTR opens
at 180°F.
FIGURE 74 -
OIL PUMP VARIABLE SPEED DRIVE (VSD)
28782A
OIL PUMP VSD
