Specifications
Ice Machine Operation Section 3
3-2 Part Number 000001759
Self-Contained Air-Cooled 
Q460/Q660/Q1060
INITIAL START-UP OR START-UP AFTER 
AUTOMATIC SHUT-OFF
1. Water Purge
Before the compressor starts, the water pump and water 
dump solenoid are energized for 45 seconds, to 
completely purge the ice machine of old water. This 
feature ensures that the ice making cycle starts with 
fresh water.
The harvest valve is also energized during water purge, 
although it stays on for an additional 5 seconds (50 
seconds total on time) during the initial refrigeration 
system start-up.
2. Refrigeration System Start-Up
The compressor starts after the 45 second water purge, 
and it remains on throughout the entire Freeze and 
Harvest Sequences. The water fill valve is energized at 
the same time as the compressor. It remains on until the 
water level sensor closes for 3 continuous seconds, or 
until a six-minute time period has expired. The harvest 
valve remains on for 5 seconds during initial compressor 
start-up and then shuts off.
At the same time the compressor starts, the condenser 
fan motor (air-cooled models) is supplied with power 
throughout the entire Freeze and Harvest Sequences. 
The fan motor is wired through a fan cycle pressure 
control, therefore it may cycle on and off. (The 
compressor and condenser fan motor are wired through 
the contactor. As a result, anytime the contactor coil is 
energized, the compressor and fan motor are supplied 
with power.)
FREEZE SEQUENCE
3. Prechill
The compressor is on for 30 seconds prior to water flow, 
to prechill the evaporator.
4. Freeze
The water pump restarts after the 30 second prechill. An 
even flow of water is directed across the evaporator and 
into each cube cell, where it freezes. The water fill valve 
will cycle on and then off one more time to refill the water 
trough.
When sufficient ice has formed, the water flow (not the 
ice) contacts the ice thickness probe. After 
approximately 7 seconds of continual water contact, the 
harvest sequence is initiated. The ice machine cannot 
initiate a harvest sequence until a 6 minute freeze lock 
has been surpassed.
Figure 3-2. Freeze Sequence  
(Typical Q460 Shown)










