Limited Service Fire Pump Controller
Page 5 of 12
Caution: Before drilling and punching holes in the cabinet for wiring
connections, cover the components inside the cabinet with a
protective covering. Debris may cause shorts or prevent operation
of components.
6. Punch holes in the top or the bottom of the cabinet for conduit.
7. Connect the water pressure sensing line to the PS (1/4 NPT internal, 3/4-16 external, brass)
fitting on the bottom of the cabinet. For further details, consult the latest edition of NFPA
20.
8. Connect the power supply conductors to the line side of the CIRCUIT BREAKER in the
correct A-B-C phase sequence.
9. Connect the motor conductors to the load side of the motor contactor.
Note
Refer to the Controller field connection diagrams. Per the requirements of NFPA 20, conductors
are sized for no less than 125% of the motor FLC (full load current) and not more than the lug
sizes provided, as shown on the Controller field connection diagrams. Refer to the NFPA 70
(NEC) for cable ratings. Secure conductors inside the cabinet so they do not interfere with or
come in contact with the components.
10. Connect the remote alarm contacts. Refer to the supplied Controller field connection
diagram for terminal points.

V Sequence of Operation

The PLM (phase loss/reversal monitor) provides contact output for phase loss and undervoltage
(PLM-2) in addition to a separate contact output for phase rotation (PLM-1). Both output relays
energize if all three phases are present and the phases are in the proper rotation. If a phase loss
or undervoltage condition occurs, only the phase loss relay de-energizes. If the phases are
reversed relative to the sequence on the PLM, only the phase reversal relay de-energizes. If there
is a total loss of the three-phase voltage, both output relays de-energize.
Closing the CIRCUIT BREAKER DISCONNECTING MEANS energizes the PLM and the
control transformer. After a 3–5 second delay, contacts PLM-1 open and the PHASE
REVERSAL light should go off. If there is a phase reversal, PLM-1 remains closed to turn on
the PHASE REVERSAL light and energize the PRR (phase reversal relay) to provide remote
indication of phase reversal. The PLM-2 contacts also close, after the 3–5 second delay, to turn
on the POWER AVAILABLE light and energize the PFR (phase failure relay) to provide remote
indication that power is available.
Automatic Start - When the PS (pressure switch) contacts close due to a decrease in pressure,
the CR relay coil energizes. The CR contacts close to energize the TR1 timing relay, factory set
at 10 minutes, to begin timing. The TR1 contacts close to latch the CR relay and bypass the PS.
The CR contacts also energize contactor coil M1 to start the motor. If the pressure increases, the
PS contacts open to de-energize the CR relay and stop the motor, if TR1 has timed out. If TR1 is