Hoshizaki 73183 B. Sequence of Operation, Sequence Cycles and Shutdown, a Refrigerator, Defrost

B. Sequence of Operation

1. Sequence Cycles and Shutdown

The steps in the sequence are as outlined below.

Note: 1. There is a slight delay at startup.

2.When power is turned on, the 2-hour high-temperature alarm timer is bypassed. Therefore, a high-temperature alarm can occur at startup. To silence the alarm, press and release the upper button. Alarm clears once temperature is within factory parameters. For details, see "II.D.2. Alarm Safeties."

3.There is a 2-minute minimum Comp on time and a 2-minute minimum Comp off time.

4.EvapFM de-energizes when door is opened on FS and when upper door is opened on HS.

5.A float-switch controlled condensate pump (located on top of the unit) is used to pump evaporator condensation to the condensate pan.

6.On freezers, EvapFM is de-energized during defrost.

a)Refrigerator

1. Startup/Cool Down

EvapFM and MH energize. There is a slight delay before cabinet temperature or high‑temperature alarm (Hi) appears on DM and Comp and ConFM energize.

2.Cool Down Achieved

CM monitors cooling of the cabinet via CTh. CTh cools to 3°F (1.7°C) below setpoint. EvapFM and MH continue. Comp and ConFM de-energize.

3.Cool Down Restart

CTh warms to 3°F (1.7°C) above setpoint. EvapFM and MH continue. Comp and ConFM energize.

4.Defrost

"dEF" is displayed during defrost. There is a 20-minute minimum defrost time and a

1-hour maximum defrost time.

a)Temperature Initiation: When DTh cools to 8.6°F (-13°C) defrost begins. EvapFM and MH continue. Comp and ConFM de‑energize.

b)Manual Initiation: Manual defrost may be initiated by pressing and holding the lower button until "dEF" appears on DM. EvapFM and MH continue. Comp and ConFM de‑energize.

c)Termination: DTh warms to 40°F (4.4°C). EvapFM and MH continue. Comp and ConFM energize, 2-minute temperature display delay timer starts.

2-minute temperature display delay timer terminates and temperature display returns to DM.

Note: There is a 2-hour minimum defrost interval.

Legend: CM–control module; Comp–compressor; ConFM–condenser fan motor; CTh–cabinet thermistor; DM–display module; DTh–defrost thermistor; EvapFM–evaporator fan motor; MH–mullion heater

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