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B. Sequence of Operation
1. Sequence Cycles and Shutdown
a) "E" Control Board
KM-320MAH-E and KM-650MAH-E Auxiliary Code U-0 and Earlier
KM-515MAH-E Auxiliary Code U-1 and Earlier
The steps in the sequence are as outlined below. When power is supplied, CB red
"POWER OK" LED comes on. There is a 5-second delay before startup. Note that the
order of the component LEDs from the outer edge of CB is 1, 4, 3, 2.
(1) 1-Minute Fill Cycle
LED 4 is on.
WV energizes and the fill period begins. After 1 minute, CB checks for
a closed F/S. If F/S is closed, the harvest cycle begins. If not, WV remains energized
through additional 1-minute fill cycles until water enters the water tank and F/S closes.
This serves as a low water safety to protect PM.
(2) Initial Harvest Cycle
LEDs 1, 4, and 2 are on.
WV remains energized, Comp and HGV energize. CB
monitors the warming of the evaporator via the thermistor located on the suction line.
When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor and
turns harvest termination over to the adjustable harvest timer (S4 dip switch 1 & 2).
The harvest timer has settings of 60, 90, 120, and 180 seconds. The pump-out timer
(S4 dip switch 3 & 4) acts in place of the harvest timer during cycles with a pump-out
(S4 dip switch 5 & 6). WV is energized during harvest for a maximum of 6 minutes or
the length of harvest, whichever is shorter. LED 4 turns off when WV de-energizes.
The minimum total time allowed by CB for a complete harvest cycle is 2 minutes. At
the end of harvest, CB checks position of F/S and proceeds to the freeze cycle if it is
closed or calls for a 1-minute fill if it is open.
(3) Freeze Cycle
LED 1 is on.
Comp remains energized, PM, FM, and LLV (KM-515MAH-E) energize.
HGV and WV de-energize. For the first 5 minutes, CB will not terminate the freeze
cycle. This minimum 5-minute freeze time is short cycle protection for Comp. As ice
builds on the evaporator, the water level in the water tank lowers. Freeze continues
until F/S opens, provided the 5-minute minimum freeze timer has terminated.