FULTON FT-0080C, Installation, Operation, Maintenance And Parts Manual

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FT-C Vertical Electric Thermal Fluid Heater Manual 12 2013 ISSUE 1
Page 63
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4.4.2
AIR SWITCH
Remove the ¼” copper tubing from the bottom of the air switch with the fan running. Air switch should
trip the interlock circuit. Re-attach copper tubing and reset the programmer.
4.4.2.1
AIR FILTER BOX SWITCH
With heater running at high fire, block opening to air filter box by 50%. Slowly close off further until
switch trips. Air filter switch should trip at just over 50% blockage.
Monitor combustion valves during this procedure.
4.4.3
LIQUID LEVEL SWITCH
Manually turn the liquid level switch cam anti-clockwise. The micro-switch will open the
contacts and control voltage will be lost. Release the cam and the micro-switch will make and
control voltage will be restored.
4.4.4
DIFFERENTIAL PRESSURE SWITCH
With the circulating pump running, observe the difference in pressure between the heater outlet
gauge and the heater inlet gauge. Remove the top cover of the differential pressure switch. Note
the original setting of the switch and turn adjustment knob clockwise until the switch trips. The
pointer on the switch should be within 0.15 barg of the observed pressure difference.
Reset the switch to the original set point.
FIG. 28 DIFFERENTIAL PRESSURE SWITCH
Differential
pressure
switch