ADJUSTMENTS
PRESSURE SWITCH:
The pressure switch should not be adjusted until it is determined to be the cause of an operating pressure difficulty. See
"Thermostat" section to determine if the source of difficulty is the pressure switch or thermostat.
The major difficulties caused by pressure switch misadjustment are:
1.
Pressure relief valve opening, especially on preheat from a cold start to 285° F (pressure switch set too high).
2.
Pressure in kettle is too low and burners are being shut down by pressure switch (not thermostat).
The pressure switch is preset for proper operation from the factory. It is adjusted to the maximum pressure which will prevent the
pressure relief valve from opening. This setting will be slightly different on different kettles due to variations in the pressure relief
valves. During preheat to the maximum thermostat setting (285° F), from either a cold condition or a lower temperature setting,
the temperature may overshoot the thermostat setting and be shut down by the pressure switch. This is normal, however, after the
kettle has cycled several times (empty) the thermostat will begin cycling the unit.
TO ADJUST PRESSURE SWITCH:
1.
With the kettle empty and completely cold, turn kettle on and set thermostat to maximum setting (285° F).
2.
Pressure in kettle (read pressure gauge on front panel) should reach a maximum pressure of 40 psi and pressure relief valve
should not open. Kettle pressure may rise 3 or 4 psi even after burners shut down.
3.
Relief valve should not open when kettle pressure is 40 psi; pressure switch setting is satisfactory.
4.
If relief valve opens, reduce setting on pressure switch, cool kettle completely by running cold water through it and repeat
this procedure.
5.
If pressure in kettle is below 40 psi increase setting of pressure switch, cool kettle completely by running cold water
through it and repeat this procedure.
6.
To obtain access to the pressure switch the front panel must be removed. Remove the screws on either side of the panel. Be
sure to support the panel to avoid excessive strain on the wiring.
7.
To increase the pressure switch setting turn the white ribbed knob clockwise; to decrease turn it counterclockwise. Use the
center of the black ring as an indicator.
8.
Replace the front panel when adjustment is complete.
GAS PRESSURE REGULATOR:
For both the standing pilot and electronic ignition units the gas pressure regulator is an integral part of the combination gas control
located just behind the lower front access door. The pressure regulator adjustment is on the lower right side of the gas control (see
pictures or wiring diagram). The large slotted cap must be removed to access the adjustment screw. (See wiring diagram or
pictures.)
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.
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 determine exact gas type and manifold pressure for your unit.
When pressure has been correctly adjusted turn unit off. Remove pressure indicating instrument and be certain to replace 1/8"
NPT plug in manifold. Replace regulator cap and close access door.
STATIONARY GAS STEAM KETTLES
SECTION THREE — SERVICE
PAGE 2
Litho in U.S.A.
5-88
