Hoshizaki DKM-500BAH service manual LED Lights and Audible Alarm Safeties, Pm, Sr, Dv

f) LED Lights and Audible Alarm Safeties

The red LED indicates proper control voltage and will remain on unless a control voltage problem occurs. At startup a 5 second delay occurs while the board conducts an internal timer check. A short beep occurs when the power switch is turned OFF.

The green LEDs 1 through 4 energize and sequence from initial startup as listed in the table below. Note that the order of the LEDs from the outer edge of the board is 1, 4, 3, 2. For more information, see "II.B. Sequence of Operation."

Sequence Step	LED	Energized		Time LEDs are On
		Components	Min.	Max.	Avg.
1 Minute Fill Cycle	4	WV			60 seconds
Harvest Cycle	1, 4, and 2	WV, HGV,	2 minutes	20 minutes	3 to 5 minutes
		Comp
Freeze Cycle	1	Comp, PM,	5 minutes	freeze timer	30 to 35 minutes
		FMS		setting
Pump Out	1, 3, and 2	Comp, HGV,	10 seconds	20 seconds	factory setting
		PM, SR, DV

The built in safeties shut down the unit and have alarms as follows:

No. of Beeps	Type of Alarm	Notes
(every 3 sec.)
1	High Evaporator Temp.	Check for harvest problem (stuck HGV or
	(temperature > 127°F)	relay), hot water entering unit, or shorted
	(53°C)	thermistor.
2	Harvest Backup Timer	Orange LED marked H TIMER lights up.
	(harvest > 20 min. for two	Check for open thermistor, HGV not
	cycles in a row)	opening, TXV leaking by, low charge, or
		inefficient compressor.
3	Freeze Timer	Yellow LED marked F TIMER lights up.
	(freeze > specified setting	Check for F/S stuck closed (up), WV
	for two cycles in a row)	leaking by, HGV leaking by, TXV not
	Timer is factory set using	feeding properly, low charge, or inefficient
	dip switches 9 & 10	compressor.
4	Short Circuit	Resistor wire harness shorted. Check
	(between the K4 connec-	and replace wire harness if necessary.
	tion on the control board
	and the bin control)
5	Open Circuit	Resistor wire harness circuit open or
	(between the K4 connec-	control board open. Check and replace
	tion on the control board	component if necessary.
	and the bin control)

To manually reset the above safeties, press the alarm reset button with the power supply on.

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