Schreiber Chillers Old 4 ton MRI - Manual (Page 9)

SPECIAL CONTROL FEATURES
1) Control LED’s for stage 1 & 2 will indicate "GREEN" when the DIS-
CHARGE temperature is above their set point without time delay.
2) Power LED's for compressor 1 & 2 will indicate "GREEN" when the
contactor driver is ON after a call for cooling from the set point and after
the time-delay has occurred.
3) Temperature alarm will have a relay with dry contacts (rated for 7A) that
will energize if DISCHARGE temperature is above set point. The Alarm
will have two modes of operation, manual and auto reset.
4) "Manual" mode WILL require an operator to reset. The alarm buzzer and
relay will remain energized and the alarm silence button is pressed.
5) "Auto" mode will NOT require an operator to reset. The alarm buzzer and
relay will remain energized while the alarm condition exists unless the
alarm silence button is pressed.
6) The audio buzzer will have a disable (OFF-ON) selection jumper on the
back side, disabling may be required when alarms are being monitored
remotely
.
7) The LOW COOLANT indicator will light "RED" when the float switch
contacts open. This condition will turn off or inhibit the COMPRESSOR
and PUMP drivers. Power indicators will turn OFF and control indications
will function normally will resume when coolant is replenished.
8) The PUMP switch will double as a standby power switch disabling the
alarm and turning the COMPRESSOR drivers OFF while continuing to
display temperatures When the PUMP switch is returned to ON, the alarm
will be disabled until the DISCHARGE temperature returns below set-
point.
9) Optional - Relay terminal block and 3 pos switch for remote power
applications These components can be assembled for an extra charge.
10) Fuse will be of the 5 x 20MM that can be replaced easily.