Operation Of Mix Pump; Mix Pump Cleaning; Disassembly And Inspection Of Removable Parts; Figure 23 Mix Pumps - Stoelting U431 Owner's Manual

3.12 OPERATION OF MIX PUMP

The pump switch is located on the front of the freezer.
When the pump switch is placed in the ON position, the mix
pump motor will be actuated to pump mix into the freezer
cylinder. When the set pressure is reached, the mix pump
will shut off automatically. When the switch is placed in the
OFF position, the mix pump will be inoperative.
The mix pump motor is equipped with an internal
overload that will "trip", disabling the pump when the
motor is overloaded. Consult the trouble shooting
section for corrective information.The internal over-
load will automatically reset after cooling. If the con-
dition continues, contact a qualified service person.
CAUTION
Risk of Product Damage
Mix pump hose must be repositioned every 1 -2 weeks
or 60 hours of operation. Failure to comply will result
in reduced mix pump liquid capacity, dispense stop-
page, popping, and possible mix pump hose leak-
age. Hose leakage may damage the pump roller as-
sembly and void the factory warranty.
A. Mix Operation: The peristaltic mix pump contains
one continuous mix pump hose. When looking at the
face of the peristaltic mix pump, the left side of the
hose is the suction or pickup. The right side of the
hose is the discharge. Mix is drawn up the suction
side of the hose and transferred thru the discharge
side to the freezer (see Figure 23).
B. Air Operation: The air compressor operates whenever
the peristaltic mix pump is running. Air enters thru a
check valve on the piston downstroke. The air is
discharged thru a second check valve, on the piston
upstroke. The air and mix join at the tee and then
travel to the freezer.
Mix
Intake
Figure 23. Mix Pumps
NOTE
Hose
Holder
Mix
Discharge
3-way Tee
C. The over-run adjustment is preset at the factory. If an
adjustment becomes necessary, refer to Section 4.
Any cleaning procedure must always be followed
by sanitizing before filling freezer with mix. (Refer to
section 3.3)

3.13 MIX PUMP CLEANING

The mix pump is approved for CIP (clean in place) and is
thoroughly cleaned as cleaning solutions are pumped thru
the freezer. We recommend completely disassembling
the pump and connecting tubing every 14 days for inspection
of parts to confirm the CIP has been properly performed. If
any residue is detected clean or replace those parts as
outlined below.
1. Place CLEAN-OFF-SERVE switch in CLEAN posi-
tion. Allow the auger to agitate for 5 to 10 minutes.
2. Remove suction tube from mix container. Draw off the
mix remaining in freezer barrel.
3. Pump 2 gallons (7.5 liters) of cold potable water thru
freezer until water at spigot is free of mix.
4. Pump 2 gallons (7.5 liters) of 90° to 110°F (32°C to
43°C) detergent solution water thru freezer. The use
of soft water is recommended, along with dishwashing
detergents such as "Joy," "Dawn," or equivalent.
5. Place mix pump switch in OFF position. Open spigot
to relieve remaining pressure.
6. Place CLEAN-OFF-SERVE switch in OFF position.
3.14 DISASSEMBLY AND INSPECTION OF
REMOVABLE PARTS
Inspection of removable parts should be made whenever
maintenance is performed or pump requires disassembly.
Hazardous Moving Parts
Revolving pump head can grab, mangle, and cause
serious crushing injury. The Power switch must be
placed in the OFF position for cleaning and power
must be disconnected when disassembling or
servicing.
CAUTION
System Under Pressure
Never disconnect hoses from freezer or pump without
first opening spigot to relieve pressure.
18
NOTICE
WARNING