CHAMPION USN72 - Manual (Page 70)

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D.) RT The device RT is the rinse tank float switch timer. This timer is a motor and clutch type
device. When the rinse tank is empty relay 7CR energizes opening 7CR N.C. This removes the
voltage from the clutch of the timer and begins the 5 second low water timing operation. After the
power has been absent for 5 seconds the N.C. contacts of RT opens causing relay 3CR to de-
energize. The N.O. contacts of 2CR in the pump and conveyor hold-in circuit (see PUMP AND
CONVEYOR HOLD-IN CIRCUIT for details) open and cause the contactors to drop out. When-
ever power is reapplied to the clutch the N.C. contact of RT closes and relay 2CR reenergizes.
Providing the rest of the hold-in circuit is satisfied the pumps and conveyor ca then be restarted
with the START button.
E.) WT The device WT is the wash tank float switch timer. This timer is a motor and clutch type
device. When the wash tank is empty relay 6CR energizes opening 6CR N.C. This removes the
voltage from the clutch of the timer and begins the 5 second low water timing operation. After the
power has been absent for 5 seconds the N.C. contacts of WT opens causing relay 2CR to de-
energize. The N.O. contacts of 3CR in the pump and conveyor hold-in circuit (see PUMP AND
CONVEYOR HOLD-IN CIRCUIT for details) open and cause the contactors to drop out.
Whenever power is reapplied to the clutch the N.C. contact of WT closes and relay 3CR reener-
gizes. Providing the rest of the hold-in circuit is satisfied the pumps and conveyor ca then be
restarted with the START button.
F.) TLS The device TLS is a table limit switch. The state of this switch drives the relay 5CR. The
contacts of this relay are used in the pump and conveyor hold-in circuit.
3.) PUMP AND CONVEYOR HOLD-IN CIRCUIT
The pump and conveyor hold-in circuit consists of switches, contacts, and buttons used to
energize the pump and conveyor contactors. This circuit is satisfied under the following condi-
tions:
A.) xMOL - The pump and drive overloads are wired in series through the N.O. contacts of each
individual overload. In the normal operating state, the switch lever is in the up position with a
white “1” visible against a black background. In this position the N.O. contacts are closed and
remain closed until an over current condition occurs that causes the contacts to open back up.
Once the cause of the fault has been corrected these overloads can be reset by flipping the switch
to the up position
B.) 5CR - The N.O. contacts of 5CR will prevent the machine continuing to operate until the
rack causing the fault is removed. This prevents racks from jamming in the machine.
C.) MSW - The MSW limit switch is located under the conveyor motor drive base and its normal
state is closed. It prevents the machine from operating if the conveyor drive mechanism senses an
over torque condition. If a rack conveyor jam occurs, the gearbox will attempt to climb the drive
chain. Since the gearbox is attached to a plate that pivots vertically, the switch opens when the
gearbox climbs the dive chain. This switch is reset by mechanically fixing the conveyor jam.
Part 5: BASIC SERVICE