Hoshizaki KM-1301SWJ/3 Service Manual page 24

f) Refrigerant Pressures, HM, and TXV Diagnosis: If evaporator is still not cooling,
check refrigerant pressures. See "VIII.A. Specification and Performance Data."
Next, check HM operation. If refrigeration pressures are above HM setpoint and
HM is bypassing, replace HM. Check TXV for proper operation. Remove TXV bulb
and hold it in your hand, refrigerant low-side pressure should rise, place TXV bulb in
ice water, refrigerant low-side pressure should drop. A 10 to 15 pound pressure swing
between warm and cold conditions indicate a good TXV. If a 10 to 15 pound swing is
not present, replace TXV.
g) WRV Diagnosis: WRV is factory set and generally no adjustment is required.
If WRV fails to open in freeze, check for proper refrigerant pressures. See "VIII.A.
Specification and Performance Data." If refrigerant pressures are correct and WRV
does not open, adjust or replace as needed. See "IV.C. Water Regulating Valve
Adjustment (water-cooled models)."
h) Freeze Termination Diagnosis: After 5 min. in freeze, disconnect CB K5 FS
connector. 15 sec. later appliance should switch out of the freeze cycle (15 second
delay after FS opens before terminating the freeze cycle). If appliance remains in
freeze longer than 15 sec. after FS removed, replace CB. If appliance switches with
FS removed but would previously not switch out of freeze with FS connected (long
freeze - 3 beep alarm), see "II.E. Float Switch Check and Cleaning."
Note: Normal freeze cycle will last 20 to 40 min. depending on model and conditions.
Cycle times and pressures should follow performance data provided in this
manual. See "VIII.A. Specification and Performance Data."
i) Short Freeze Cycle Diagnosis: Confirm water tank fills and overflows during fill and
harvest cycles. If not, check water supply filters, shut-off valve, WV screen. If water
tank empties before 5 min. timer terminates and freeze cycle is short, check that CV
is not leaking by (water flowing down the potable drain). If CV is leaking by, remove
and clean CV, replace rubber seat and spring if necessary. If water tank is full, see
"II.E. Float Switch Check and Cleaning." for erratic FS.
7) Pump-Out Cycle – LEDs 1, 3, and 2 are on (10/20 second pump-out). Timing of the
first pump-out is determined by S4 dip switch 5. See the table below.
Comp, FM* (if connected to CB K1 connector pin #9), and FMR continue, HGV
energizes. If S4 dip switch 3 & 4 are set to 3 off and 4 on, LED 4 turns on and WV
and X11 relay energize, energizing X10 relay. NOTICE! S4 dip switch 3 & 4 must
not be set to 3 off and 4 on. Otherwise, PM will rotate in freeze cycle direction
instead of pump-out direction. FM (if connected to CB K1 connector pin #3) and
LLV de-energize. PM stops for 2 sec., then reverses for 10/20 sec. depending on
pump-out timer (S4 dip switch 3 & 4) setting. When the pump-out timer terminates,
"J" Control Board Settings
S4 Dip
Switch
Pump-Out
Setting
Frequency
No. 5
OFF Every 10 cycles
ON Every cycle
1st Pump-Out
"J" Control Board
After 11th freeze cycle
After 2nd freeze cycle
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