Harvest Cycle - Sub-Zero UC-15I Service Manual

Model UC-15I (Undercounter Ice Machine)
SEQUENCE OF OPERATION
The Sequence of Operation table below provides a quick overview of the different operational events that the ice-
maker will experience under normal conditions. Following the table, wire diagrams are used to illustrate which com-
ponents are energized during each event and additional information is provided. For the freeze cycle and the har-
vest cycle, diagrams of the water system and refrigeration system are included to help illustrate what is happening
inside the ice machine during those cycles.
SEQUENCE
(EVENT)
(RELAY)
Initial Start-up /
Start-up after
Automatic Shut-off
Refrigeration
System Start-up
Freeze Cycle

Harvest Cycle

Automatic Shut-off
* Maximum freeze cycle allowed by electronic control is one-hundred and twenty (120) minutes.
** Minimum harvest cycle allowed by electronic control is sixty (60) seconds.
SEQUENCE OF OPERATION
Water Hot Gas
Water
Pump Inlet (Harvest)
Valve
(4) (5)
ON ON
ON ON
ON OFF
OFF ON
OFF OFF
Compressor
Valve
(2) (1)
ON OFF
ON ON
OFF ON
ON ON
OFF OFF
3-5
Theory of Operation
Fan
Motor
Duration
(3)
OFF 175 Seconds
ON 5 Seconds
* Automatically
Determined at
ON
Beginning of
Freeze Cycle
** Automatically
ON
Determined During
or
Last Minute of
OFF
Freeze Cycle
Until Bin Thermostat
OFF
Re-closes
#7012423 - Revision A - August, 2009