Vogt Tube-Ice HFO10, Service Manual

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9-3
Hand Expansion Valve
The hand expansion valve is located after the liquid line solenoid valve (A). This should be set at a point where
the float switch is open for a length of time approximately equal to the time it is closed. The factory setting is
about three turns closed from full open.
Freezer Pressure Switch (Vogt 450)
The freezer pressure switch (FPS), Output #1 of the Vogt 450, controls the freezing time period for the
production of cylinder or crushed ice.
This switch is set at the factory to produce ice of recommended thickness. Refer to the Certificate of Test, which
was provided with the machine for a sample set of pressure readings with corresponding time periods and water
temperatures. Do not make adjustments until several ice discharging cycles have been completed.
Low-Pressure Safety Switch (Vogt 450)
The compressor’s low-pressure safety switch, Output #3 of the Vogt 450, has electrical contacts, will shut the ice
machine off if the compressor suction pressure drops below the cut-out setpoint. The factory setpoint for the
low-pressure safety is 5 psig (0.3 bar). The cut-in point where the output contacts
“close” is 20 psig (1.4 bar).
High-Pressure Safety Switch (Vogt 450)
The compressor’s high-pressure safety switch, Output #4 of the Vogt 450, will shut the ice machine off if the
compressor discharge pressure reaches the cut-out setpoint. The factory setpoint for the maximum safe
pressure is 200 psig (13.8 bar). The cut-in point where the output
contacts “close” is 175 psig (12.1 bar).
Head Pressure (Vogt 450)
For R513A, the head pressure should be maintained at 130 – 140 psig (9 – 9.7 bar) for water-cooled machines and
135 – 145 psig (9.3 – 10 bar) for air-cooled machines during the freeze cycle. This pressure can be checked at the
compressor discharge valve. It is also displayed on the Vogt 450.
Fan Cycling Switch (Air-Cooled Machines, Vogt 450)
For air-cooled machines, the condenser fan cycling is controlled by the Vogt 450. To set the cut in and cut out,
adjust OUTR6 on the Vogt 450. Best performance is achieved with a head pressure range of 135
– 145 (9.3 – 10
bar) psig.