Manual Control; Thermostat Calibration - Alto-Shaam 500-1D MARINE Operation And Care Manual

SERVICE - MANUAL CONTROL

MANUAL CONTROL

THERMOSTAT and HEAT LIGHT SEQUENCE
Whenever the thermostat is turned "ON," the heat indicator light will indicate the power ON/OFF
condition of the heating cable, and consequently, the cycling of the cabinet as it maintains the dialed cavity
temperature. If the light does not illuminate after normal start-up, the main power source, thermostat,
and/or light must be checked. If the warming cabinet does not hold the temperature as dialed, the
calibration of the thermostat must be checked. If the warmer fails to heat or heats continuously with the
thermostat "OFF," the thermostat must be initially checked for proper operation. If these items are
checked and found to be in order, a continuity and resistance check of the heating cable should be made.
SEE CIRCUIT DIAGRAM.

THERMOSTAT CALIBRATION

The thermostat is precision calibrated at the factory. Normally, no adjustment or recalibration is necessary
unless the thermostat has been mishandled in transit, changed or abused while in service. A thermostat
with a sensing bulb operates on hydraulic pressure, consequently, any bending of the bulb results in a
change in its volume, and alters the accuracy of the thermostat calibration.
A thermostat should be checked or recalibrated by placing a quality, thermal indicator at the center of an
empty holding cavity. DO NOT CALIBRATE WITH ANY FOOD PRODUCT IN THE CABINET. The
thermostat should be set at 140°F (60°C), and should be allowed to stabilize at that setting for a minimum
of one hour. Following temperature stabilization, the center of the thermal swing of the air temperature
within the cabinet should approximately coincide with the thermostat dial setting.
If calibration is necessary, the calibration screw should be adjusted with great care. The calibration screw
of the thermostat is located in the thermostat dial shaft. With the shaft held stationary, a minute, clockwise
motion of the calibration screw appreciably lowers the thermostat setting. A reverse, or counter-clockwise
motion appreciably raises the thermostat setting. After achieving the desired cycling of the thermostat, the
calibration screw must be sealed. Place a few drops of enamel sealant directly on the calibration screw.
(RED NAIL POLISH OR EQUIVALENT IS ACCEPTABLE.)
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