Bunn JDF Silver Series, Техническое учебное пособие

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JDF Silver Series Training Manual
14
Both transformers are 120VAC on the primary side and step the voltage down to 24VAC on
the secondary side of the transformer. Each transformer is protected on the “load” side with
a resettable PTC fuse. The Poly Switch Polymeric Positive Temperature Coefficient (PPTC)
device used on the load side of the transformers will help protect against harmful over/cur-
rent surges, voltage and over/temperature faults. The PPTC device will reset after the fault
is cleared and power to the circuit is removed.
Dispense Lockout Switch (C)
The dispense lockout switch is located on the bottom front behind the drip tray. The switch is used to
lockout the dispense functions of the dispenser to prevent unauthorized use of the dispenser, while
keeping the refrigeration system running. Early juice machines before the release of the program
switch also used the dispense lockout switch to enter the water bath fill mode, semi-automatic sani -
tizing mode and brixing test modes.
A field retrofit kit is available to convert old style JDF-S machines to the new style should a customer request it. The
PN for the retrofit kit is 44140.0000 and applies only to mechanical switch dispensers. At this time a kit is not offered
for membrane switch models. Installation of the retrofit kit is considered elective and is not covered by warranty. Re -
fer to service bulletin 189 for details regarding the change.
Compressor Relay K1 (D)
The compressor relay is the component that will pass 120VAC power to the
compressor. By switching the refrigeration to the on position, 120VAC will be
present on one contact terminal waiting to pass on. The relay coil (K1) will
receive 120VAC from the main control board after a 6 minute delay from initial
plug-in and energize, closing the relay contacts. With the contacts closed
120VAC will pass across the contact and onto the compressor limit thermostat
and energize the compressor start and run winding.
Control Board Assembly (CBA) (E)
The CBA is powered by receiving 24VAC from one of the step down
transformers. The CBA microprocessor will receive input signals and in
return will control a sequence event or an output of power to the other
components used throughout the machine. The CBA is responsible of
converting 24VAC to D/C voltage to support the voltage adjustment
dials located at the bottom of the CBA for the pump motor rpm ,cabinet
fan and dispense valve. The pump speed adjustment dials range 9 to
24VDC.
Other power distributed is 120VAC to inlet valve, compressor run relay,
transformer and condenser fan motor. The CBA will further step down
the voltage to 5VDC for door switches, dispense lockout switch and
water and bath thermistor.
CBA Connector Identification (BUNN P/N: 40177.1000)
J-1: 120VAC supply to the CB for inlet water valve, 120VAC output to
water valve
J-2: Pump motor 1 and 2 and water valves 1 and 2
J-3: Cabinet fan
J-5: Dispense lockout switch
J-6: Power/Lower transformer (Transformer B)
J-7: Cabinet thermistor
J-8: Not used
J-9: Water bath thermistor
J-11: Door auxiliary board
J-12: Right power for stations 3 and 4 (Transformer A)
J-13: Pump motor 3 and 4 and water valves 3 and 4
J-15: Not used
PPTC
1
J1
J2
J3
J5
J6
J7
J9
J8
J13
J11
J15
J12
2
1
2
3
4
5
1
2
3
4
5
6
1
2
3
6
5
4
1 2
1 2
2 1
1
2
3 4
1
2
3
4
5
3 2 1
3
2
1
1 3
2 4
Left
Station
Middle Left
Station
Middle Right
Station
Right
Station
Relay Coil - Labeled K1
On Wiring Schematic
Relay Contact