Howe Rapid Freeze, Service Manual

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15 Service & Adjustment
SELECTIVE PURPOSE Manual Page (62)
tighten the flare nuts. Re-attach the bulb to the suction line, at approximately 5 o-clock position. Secure
the bulb using two straps. Re-insulate the suction line. Using a high quality vacuum pump, evacuate the
liquid line to remove any moisture that may have entered the system while the line was open to
atmosphere.
ADJUSTMENT OF EXPANSION VALVE
If ice freezes on surface of evaporator (top to bottom) but harvests only the upper portion with each
revolution of the shaft
and
there are no bubbles in the sight glass, then the expansion valve must be
adjusted. (opened, to feed more refrigerant). On the other hand, frost on the compressor body indicates
that the valve is overfeeding.
Remove the adjustment stem cover and turn the adjustment stem 1/8 to 1/4 turn at a time (clockwise to
close the valve if it was overfeeding, counterclockwise to open the valve if the evaporator was not
harvesting ice on its entire length.) Wait 5-10 minutes between each adjustment to allow the valve to
stabilize. Repeat this step until ice is produced and harvested all the way down to the bottom of the
evaporator. Note:
Balanced Port Expansion Valves Are more sensitive than normal TXV's, so adjustment of
the stem should be limited to between 1/16 to
c
turn at a time.
*** SPECIAL NOTE ***
ON SINGLE CIRCUIT MACHINES WITH DUAL TXV VALVES, (101E-1, 76E-1, 75E,
100E) CLOSE BOTH VALVES, AND OPEN BOTH EQUALLY 1/4 TO
2
TURN EACH
UNTIL ICE IS MADE AND HARVESTED ON THE ENTIRE LENGTH OF THE
EVAPORATOR. WAIT 5-10 MINUTES BETWEEN EACH ADJUSTMENT.
*** SPECIAL NOTE ***
REPLACEMENT OF SOLENOID VALVE
*** SPECIAL NOTE ***
On flakers SUPPLIED WITH HOWE CONTROL PANELS that are connected to a
central refrigeration rack system, a jumper wire must be placed between terminal
"Line
A
" and terminal "L
2
". This jumper will allow the solenoid valve to energize
when the operating circuit is energized.
*** SPECIAL NOTE ***