9
B. Sequence of Operation
1. Sequence Cycles and Shutdown
The steps in the sequence are as outlined below.This unit utilizes a control board to
switch the components on and off as needed. When power is supplied and the power
switch is in the "ON" position, CB red "POWER OK" LED comes on and CB revision
(r###) appears on DB.
Note: 1. "POWER OK" LED remains on until the power switch is moved to the "OFF"
position, the power supply is turned off, or the unit is unplugged from the
electrical outlet.
2. There is a minimum 2.5-minute Comp on time and 2.5-minute Comp off time.
a) Startup
No Component LED on:
EvapFM energizes. 2.5-minute Comp delay timer starts.
Cabinet temperature appears on DB.
b) Cool Down
LEDs 4 and 5 on:
2.5-minute Comp delay timer terminates, EvapFM continues,
Comp, ConFM, and PH energize.
c) Cool Down Achieved
No Component LED on:
CB monitors cooling of the cabinet via CTh. CTh cools to
3
°
F (1.7
°
C) below setpoint. EvapFM continues, Comp, ConFM, and PH de-energize.
d) Cool Down Restart
LEDs 4 and 5 on:
CTh warms to 3
°
F (1.7
°
C) above setpoint. EvapFM continues,
Comp, ConFM, and PH energize.
e) Defrost
LED 5 on:
(1a) Temperature-Initiated Defrost
DTh cools to 13°F (-10°C). Comp and PH, if energized, de-energize, EvapFM
continues. If energized, ConFM continues, otherwise, ConFM energizes. Cabinet
temperature is displayed on DB during defrost.
(1b) Optional Time-Initiated Defrost
The optional time-initiated defrost is factory set to 0 times per day. Before
changing this setting, contact Hoshizaki Technical Support at 1-800-233-1940 for
recommendations.
When set to greater than 0, defrost initiates when the defrost timer terminates. For
further details, see "II.D.5.b) Defrost Frequency."
(2) Defrost Termination
DTh warms to 40
°
F (4.4
°
C). EvapFM and ConFM continue. 2.5 minute delay
before Comp and PH energize.
Legend:
CB
–control board;
ConFM
–condenser fan motor;
Comp
–compressor;
CTh
–cabinet thermistor;
DB
–display board;
DTh
–defrost thermistor;
EvapFM
–evaporator fan motor;
PH
–perimeter heater
