Technical information

12/01/02
KM CHECK OUT PROCEDURE
The following is a detailed explanation of the KM 10
Minute Check Out procedure.
The 10 minute check out procedure is basically a
sequence check which can be used at unit start-up or
for system diagnosis. Using this check out procedure
will allow you to diagnose electrical system and
component failures in approximately 10 minutes under
normal operating conditions of 70°F or warmer air and
50°F or warmer water temperatures. Before conducting
a 10 minute checkout, check for correct installation,
proper voltage per unit nameplate and adequate water
supply. As you go through the procedure, check to
assure the components energize and de-energize
correctly. If not, those components and controls are
suspect.
10 MINUTE CHECK OUT PROCEDURE
1. Turn power OFF - gain access to unit control box.
2. Turn power ON – place control switch in ice position.
Note: A 5 second delay occurs for units with “E” control
board.
A) 1 Minute Fill Cycle begins – WV energized.
After 1 minute, control board checks FS. If FS is
closed…unit cycles to Harvest. Continue to (B).
If FS is open, unit repeats 1 minute fill cycle until
water enters and FS closes (low water safety
protection during initial start up and at the end of
each harvest)
Diagnosis: If WV does not open, check for no supply
voltage at WV terminals, bad coil, or plugged screen
or external filter (no water flow). If unit fails to start
harvest, check for open FS or bad 1 minute timer in
board.
B) Initial Harvest Cycle – WV remains energized,
CC energizes to start C, HGV, & (FM on RS
model) energize. Evaporator warms…thermistor
senses 48°F…turns operation of harvest to
control board defrost completion timer. Timer
completes counting (1 ~3 minutes)…Unit cycles
to freeze.
Diagnosis: Check if C is running, HGV is open, WV
still open. Avg. harvest cycle at factory setting is 2
~ 3 minutes. How long does initial harvest last? 1.5
minutes after initial harvest begins, touch C
discharge line. Is it hot? If not check refrigerant
pressures and C operation. If it is hot, touch inlet
line to the evaporator. Is it hot? If it is hot and unit is
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12/20/03
2/20/03