Hoshizaki MRH KM-600MAH KM-650MAH Harvest Timer S4 dip switch 1, Pump-Out Timer S4 dip switch 3

2. Harvest Timer (S4 dip switch 1 & 2)

The harvest timer starts counting when the thermistor reaches 48°F (9°C) at the evaporator outlet and the control board reads 3.9 kΩ from the thermistor. The harvest timer is factory set, and generally no adjustment is required. However, a setting longer than the factory setting may be advised in cases where the drain provided at harvest needs to be prolonged for extra cleaning. Before changing this setting, contact Hoshizaki Technical Support at 1‑800‑233-1940 for recommendations. Keep in mind that setting the harvest timer to a longer setting decreases 24-hour production.

Note that the pump-out timer (S4 dip switch 3 & 4) acts in place of the harvest timer during cycles with a pump out. For details, see "III.C.3. Pump-Out Timer (S4 dip switch 3 & 4)."

Note: On models with a pump-out every cycle, the harvest timer is only relevant during

the initial harvest cycle since a pump out occurs every cycle thereafter.

S4 Dip Switch Setting		Time
		(sec.)
No. 1	No. 2
OFF	OFF	60
ON	OFF	90
OFF	ON	120
ON	ON	180

3. Pump-Out Timer (S4 dip switch 3 & 4)

NOTICE

•On KM-515M_H models without harvest pump timer operation, never adjust the pump-out timer's harvest timer (T2) for a time less than 150 sec. Otherwise, the icemaker will not perform properly.

•On models with harvest pump timer, do not adjust 3 off and 4 on. Pump does not run in pump-out rotation in this setting.

When a pump-out is called for, the pump motor stops for 2 sec., then energizes in the reverse direction, taking water from the bottom of the water tank and forcing pressure against the check valve seat allowing water to go through the check valve and down the drain. At the same time, water flows through the small tube to power flush the float switch. The pump motor drains the water tank for the time determined by the pump-out timer. The pump‑out timer also acts in place of the harvest timer during cycles with a pump‑out. The pump-out timer is factory set, and generally no adjustment is required. However, where water quality is bad and the icemaker needs a longer pump-out time, the pump‑out timer can be adjusted. The pump‑out timer control can be set to pump-out for 10 or 20 sec.

S4 Dip Switch Setting		Time (sec.)		Inlet Water
No. 3	No. 4	T1	T2	Valve
OFF	OFF	10	150	Closed
ON	OFF	10	180	Closed
OFF	ON	10	120	Open
ON	ON	20	180	Closed

T1: Time to drain the water tank

T2: Harvest timer at pump out

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