Manitowoc J250 Service Manual page 65

Electrical System
Harvest Sequence
5. WATER PURGE
The water pump continues to run as the
water dump valve energizes for 45
seconds to purge the water from the water
trough.
The hot gas valve(s) and HPR solenoid
valve open at the beginning of the water
purge. Hot refrigerant gas is diverted into
the evaporator throughout the 45-second
water purge.
After the 45-second water purge, the
water pump and dump valve de-energize.
New style control boards have an
adjustable water purge. This permits a 0
(off), 15, 30 or 45 second water purge.
Remote Models
Toggle Switch
Bin Switch
Control Board Relays
#1
Water Pump
#2
Hot Gas Solenoid
Harvest Pressure Regulating (HPR) Solenoid
#3
Water Dump Valve
#4
Contactor Coil
Liquid Line Solenoid
Compressor
Condenser Fan Motor
Safety Controls (Which could stop ice machine operation)
High Pressure Cut-Out
Main Fuse (On Control Board)
Transformer Fuse (On Control Board)
Thermistor Operation
6-14
L1
TB32 (55)
TB35
HIGH
PRESSURE
CUT-OUT
ICE THICKNESS PROBE
DISCHARGE LINE THERMISTOR
BIN SWITCH
(64)
(66)
CONTACTOR
CONTACTS
*OVERLOAD
(42) (48)
TB35
(51)
L1
(52)
TB33
(Old Style Control Board Shown)
5. Water Purge (45 Seconds)
(61)
(60)
3
1
2
4
(57)
TB31
TRANS. FUSE
(58)
FUSE (7A)
TB37
1D
1C
1B
HARVEST LIGHT/
1A
LOW D.C.
SAFETY LIMIT CODE LIGHT
VOLTAGE
PLUG
(62)
BIN SWITCH LIGHT
(63)
TOGGLE SWITCH
(65)
(68)
(67)
ICE
← ← ← ← INTERNAL
(69)
(66) OFF
WORKING VIEW
CLEAN
(62)
(49)
COMPRESSOR RUN CAPACITOR
(47)
R S
(46)
C
PTCR
(53)
TERMINATES AT
TB34
PIN CONNECTION
(F1)
REMOTE FAN
MOTOR
RUN CAPACITOR
ICE
Closed
Closed
ON
Closed
ON
ON
Closed
ON
Closed
ON
Energized
ON
ON
Closed
Closed
Closed
OK
Section 6
SEE SERIAL PLATE FOR VOLTAGE
L2 (N)
HPR
SOLENOID
(78) (79)
(71)
(80)
HOT GAS
SOLENOID
(76) (75)
TB30
(81)
DUMP
SOLENOID
(98) (99)
TB30
WATER
PUMP
(59) (83) (82)
LIQUID LINE
SOLENOID
(73)
TB30
(74)
CONTACTOR
(56)
COIL
TB30
VIEW FOR WIRING
68
66 67
62
69
R R
(50)
TB30
(45)
(F2)
TB30
REMOTE
CONDENSER
SV1556