Vogt P18AL TUBE-ICE, Service Manual

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P18AL Service Manual
SERVICE OPERATIONS
3/6/07
9-3
Make-up Water Float Valve (37A). The make-up float valve maintains the proper level in the
water tank for ice making. The valve should be set to maintain a water level in the water tank during
the freezing period so that there will be a quantity of blowdown only during the thaw mode. The
water level during the freeze mode should always be below the overflow piping to prevent excessive
waste of cold water, resulting in loss of ice capacity.
If it should become necessary to clean the float valve, close the stop valve in the make-up water line
to the machine and remove the float valve. After the valve has been cleaned and reinstalled, check
to ascertain if the proper water level is being maintained. After the machine is stopped and the water
in the tank seeks its normal level, there should be no water flow through the float valve or overflow.
It is advisable to install a large area strainer in the water supply line to protect the float valve from
dirt or solids in the water that would necessitate frequent cleaning. A strainer of 40-mesh screen is
usually satisfactory.
Refrigerant Float Switch (23). The float switch is installed on a header assembly that is attached
to the freezer shell. Valves are provided for isolation of the float switch assembly if replacement or
servicing is necessary. The float switch closes as the level of refrigerant in the freezer rises and
opens as the level falls.
The float switch is connected to the “A” solenoid valve coil. This is the solenoid valve directly
before the hand expansion valve. Therefore when the refrigerant level in the freezer drops, the float
switch closes, thereby energizing and opening the “A” liquid feed solenoid until sufficient level has
been reached to open the float switch. The float switch has a fixed 1/2” differential.
The float switch is installed at the correct height at the factory and should not need to be adjusted.
The float switch is installed at the position that provides highest capacity. The correct height will
produce compressor superheat, which climbs throughout the freeze cycle to a minimum of 30° F.
Hand Expansion Valve (9).
The hand expansion valve is located directly after the “A” solenoid
valve. This valve 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.
Solenoid Valves (18,25). All solenoid valves are pilot operated with “floating” type diaphragms.
For satisfactory operation be sure that the manual opening stem is in the closed or automatic
position. This means the stem is backed all the way out. Correct direction of stem rotation should
be labeled on the stem seal nut.
Control Circuit Protection (CB1).
The electrical control circuit of the machine is protected by a 3
amp circuit breaker. If breaker should open, the machine will immediately stop. Before resetting
the breaker, check power to the machine and set the “On/Off” switch to the “off” position. If the
machine was off for an extended time the crankcase heater must be energized for a minimum of two
hours before restarting the machine. When ready to restart the machine, depress the “Start” button.
The machine will automatically return to a freeze cycle upon completion of the harvest cycle.
Cutter Motor (3)/Gear Reducer (4). The gear reducer supplied requires no lubrication. It is
lubricated from the original manufacturer for life. Do not attempt to lubricate the gear reducer. The
motor bearings are also prelubricated and require no further lubrication.
Circulating Water Pump Motor (5) . The motor bearings are prelubricated and sealed. They
require no further lubrication. The pump should operate with the water level above the impeller