Crown GL-20E Installation & Operation Manual page 26

INSTALLATION AND OPERATION MANUAL, GAS KETTLES
6.0 SERVICE (Continued)
To check the manifold pressure a pressure gauge (manometer) must be connected to the 1/8"
NPT pressure tap on the gas manifold. With the gas off, connect your pressure indicating
instrument to the manifold with a fitting appropriate for your instrument.
1. Turn the unit on; with main burners on, read the manifold pressure. The pressure should
be 4 inches water column (W.C.) (±) .2 inches W.C. for natural gas or 10 inches W.C. for
propane gas. Adjust the pressure regulator to obtain the appropriate pressure. Check
serial plate on lower right side of unit to confirm exact gas type and manifold pressure for
your unit.
When pressure has been correctly adjusted turn unit off. Remove pressure indicating
instrument and replace the 1/8" NPT plug in manifold. Replace regulator cap and close access
door.
THERMOSTAT
The thermostat adjustment should not be changed. Check the following before changing the
thermostat:
1. With kettle cool, the pressure reading on the pressure gauge should be in the green
vacuum zone (below 0 psi). If not, see "Re-establishing Vacuum" section.
2. Check that the pressure switch is not set too high or too low and causing the out of
adjustment condition. A voltmeter should be used by a properly trained serviceman to
determine if the pressure switch or thermostat is actually cycling the burners. If the
pressure switch is found to be the problem, see "Pressure Switch" section.
After verifying that the pressure switch is set and operating properly, the thermostat may be
adjusted using the set screw inside the stem. The thermostat should cycle off at a gauge
pressure reading of 30 psi. Turn set screw clockwise to decrease pressure and
counterclockwise to increase pressure.
PRESSURE SWITCH
The pressure switch should not be adjusted until it is determined to be the cause of an
operating pressure deficiency. See "Thermostat" section to determine if the source of difficulty
is the pressure switch or thermostat.
The major difficulties caused by pressure switch mis-adjustment are:
10125R4
Models GL-20E, GL-40E, GL-60E, GL-80E, GL-100E
26 2017-08-29