Vogt P18FXT, Service Manual

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10TA Service Manual
SERVICE OPERATIONS
4/28/14
9-10
Sentronic Module
(2D, 3D, 4D & 6D compressors before March 2011). The Sentronic has in
addition to the (N) contact, used for compressor shutdown, a Normally Open (N.O.) contact that
can be used in an alarm circuit. The Single Pole Double Throw (S.P.D.T.) contact of Sentronic
can be electrically isolated from the control circuit power supply, and used to control a circuit with
a different voltage (See Figure 6-3). The Sentronic has a timing circuit that actually compares the
amount of time with good oil pressure to that with insufficient oil pressure. The module memory
will shut the compressor down after a period of more than two minutes if the compressor has a
"history" of oil pressure fluctuations with more unacceptable than acceptable pressures.
Sentronic also has a memory that retains the compressor oil pressure "history" for up to one minute
in the event of a power loss. Sentronic uses a permanent magnet integral with the reset button to
reset its output control relay in the event of a trip. When the reset button is depressed, it
magnetically pulls the Sentronic relay's armature to its original, reset position. Sentronic needs no
voltage present to reset.
Coresense Protection
Discus compressors manufactured after March 2011 will be supplied with CoreSense Protection.
CoreSense replaces the Sentronic Oil Pressure Safety Module on all Discus compressors and the
Electronic Motor Protector Module on 4D & 6D compressors. Note: 2D & 3D compressors will
continue to have Internal Line Break overload protection.
The oil pressure monitoring portion of the CoreSense will act very similar to the Sentronic Oil
Pressure Safety switch. A current transformer (CT) in the compressor junction box determines
when the compressor is running and starts monitoring oil pressure. Note: Wire “T1” passes
through CT before connecting to compressor terminal.
The CoreSense module has power applied at all times to allow for more detailed fault notification.
An LED will flash when a fault occurs. The number of flashes will identify the fault condition.
# of Flashes Condition
1 Oil Pressure
2 Motor Protection Trip
3 Discharge Temperature (optional add-on)
4 Current Sensor Fault
5 Communication Error
FIGURE 9-7B
CoreSense Protection
3
22
22
6