Temperature Controller Adjustment And Service - pick heaters 6X7 Service Manual

PICK VARIABLE FLOW SERVICE MANUAL
temperature control problems; however,
several other components also affect
temperature control. All should be checked
before replacing the temperature controller.
CALIBRATION
Adjust the controller until the outlet
thermometer is at the desired temperature.
Loosen the control knob set screw. Turn the
knob to the indicated temperature. Tighten
the set screw. (A 3/32 inch Allen wrench is
required.)
ADJUSTMENT OF STANDARD PICK
TEMPERATURE CONTROLLERS
Confirm the air pressure regulator setting of
20 psi. If the pressure gauge has a dual
scale (English/Metric), be sure to take
readings from the psi scale (English).
IMPORTANT: Manual steam valve and
air valves must be closed when servicing
the temperature controller. FIGURE 5.
Check the sensitivity adjustment screw,
located on the bottom of the controller near
the air supply inlet. (It may be covered with
a sealant which can be removed.) Remove
the adjustment screw, and allow air to blow
out through the opening to make sure it is
clear.
Wipe off the needle and resinstall. Turn the
adjustment screw in all the way, then open
one-half turn. The adjustment screw may
need to be further adjusted (a maximum of
one-quarter turn in either direction) for best
control. Make adjustment in one-eighth-turn
increments. Give the heater time to respond
between adjustment.
Check the supply and control ports. The
supply from the regulator enters the
controller from the right when looking at the
nameplate in the upright position. The left
port should be connected to the tubing going
to the steam valve.
Note: The supply is marked with an "S" and
the control port is marked "R" on the bottom
of the controller.
Check the control knob and calibration. The
control knob might be loose and may not
actually be turning the shaft. If the stop pin
has been sheared, the controller may be one
or more turns out of calibration. To check,
remove the control knob by loosening the
set screw. Turn the shaft to obtain correct
temperature. Install the knob to indicate the
actual water temperature. Tighten the set
screw.
REPAIRS OF THE STEANDARD PICK
TEMPERATURE CONTROLLERS
All needed repairs on standard temperature
controllers should be performed at the
factory. To minimize heater downtime, Pick
Heaters will send a fully-warranted, factory
rebuilt temperature controller in exchange
for a used controller. Used controllers are
reworked and placed in factory rebuilt stock.
CONTROLLER LINKAGE
ADJUSTMENT
Set knob to cold. Remove knob and
nameplate to expose inner mechanism.
Check movement of thermal valve arm to
make sure arm is centered over valve seat
and has a slight sideplay. If necessary,
correct movement by adjusting pivot screws.
Reinstall nameplate and knob. When heater
is operating satisfactorily it may be
necessary to recalibrate the temperature
controller.
ADJUSTMENT AND MAINTENANCE
OF OPTIONAL TEMPERATURE
CONTROLLERS
If the Pick heater is equipped with an
optional temperature controller, follow the
adjustment and calibration procedures as
detailed in the separate temperature
controller manual furnished with the heater.
Service or repair of theses units must be
performed by qualified individuals.
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