Vogt P-34AL-15, Service Manual

Page: 93 / 159

P34AL-15 & P34ALOF-15 Service Manual
SERVICING OPERATIONS
9/22/05
9-5
FIGURE 9-3
ASCO Freezer Pressure Switch (2PS)
It is preferable that the freezing cycle be such that a small diameter hole remains in the center of the
ice cylinder (1/16” diameter for 7/8” diameter ice, 1/8” diameter for 1 1/8” diameter ice, 1/4”
diameter for 1 3/8” diameter ice). This insures that the freezing cycle is not extended unnecessarily
and eliminates a possible opaque core in the center of the ice, as well as a loss of production.
Control Circuit Protection. The electrical control circuit of the machine is protected by a 6 amp
circuit breaker (CB4). If this breaker should open, the machine will immediately stop. Before
resetting the circuit breaker, open the disconnect switch and lock-out all power to the control panel.
Reset CB4 and restore power. Check circuitry with a volt meter. If the machine was off for an
extended time, the crankcase heater must be energized for a minimum of four (4) hours and no liquid
refrigerant in the crankcase before restarting the machine. When ready to restart the machine,
depress the “Start” button. As usual, initiate a harvest cycle if there is ice remaining in the freezer.
Check Amp draw through the breaker for excessive load or unbalance.
Thawing Timer. The thawing timer (2TR), Figure 9-4, governs the ice thawing period. It is
located inside the control panel (FIGURE 6-1). It is started by action of the freeze timer (2TR) or
freezer pressure switch (2PS), which energized the “1CR” relay. This timer is set prior to shipment
for approximately a three minute period. To replace the timer, simply pull the timer from its base
and plug in another, set to “X1” and “Min” and set the thawing period for at least 30 seconds longer
than the time required to harvest the entire discharge of ice. If it should be necessary to change the
setting of the timer, turn the adjustment dial clockwise to increase the time or counter-clockwise to
decrease the time. Check the thaw time after each adjustment.
Note: Thicker ice may require a longer thaw period, due to slower ice release time.