Adjustment Procedures
6-26
750-211 (revised 2009)
Promethean Boilers, Model 4WI Manual
6.23 — Oil Drawer Switch
The integral contacts of the control are closed by proper positioning and latching of the oil nozzle lance in its for-
ward position. Adjustment of the switch must be such that its contacts open if the oil nozzle lance is not properly
positioned for oil firing. The switch is electrically removed from the circuit when a combination fuel burner is fired
on gas.
6.24 — Low-Oil-Temperature Switch: Heavy Oil
The LOTS prevents the burner from starting, or stops its operation, if the temperature of the oil is below normal
operating temperature.
To adjust the control, insert a screwdriver into the center slot in the control cover and turn the dial until the fixed
(center) pointer is approximately 30º F lower than the oil heater thermostat setting. Turn the differential adjusting
screw (located above the dial) until the movable indicator is approximately 5º F above the setting on the main scale.
On a hot water boiler, the LOTS is an integral part of the electric oil heater. The switch is non-adjustable and is fac-
tory set at approximately 40º F below the maximum operating temperature of the heater.
6.25 — High-Oil-Temperature Switch: Optional
The HOTS prevents the burner from starting, or stops its operation, if the temperature of the oil exceeds the nor-
mal operating temperature.
To adjust, turn the dial until the pointer is approximately 25º F above the normal operating temperature. The con-
trols generally have a set differential and will close 5º F below the setpoint.
6.26 — Low-Oil-Pressure Switch: Optional
The LOPS prevents burner ignition, or stops its operation when the oil pressure is below the setpoint. Adjust the
control by turning the screw on top of the control case to an indicated pressure 10 psi below the established pri-
mary oil pressure setting indicated on the oil supply pressure gauge. The switch will remain in a closed position as
long as the oil pressure exceeds this setting. The control normally uses automatic reset when pressure is restored
after a drop.
6.27 — Electric Oil Heater Thermostat: 400 and 600 Series (Steam)
The maximum temperature setting of the control is stamped on the dial. The maximum temperature setting is
attained with the adjusting knob turned to the “high” end of the scale. Lower settings are obtained by turning the
adjusting knob clockwise using the thermometer in the fuel oil controller as a guide.
Summary of Contents for 4WI
Page 46: ...Burner Operation and Control 2 22 750 211 revised 2009 Promethean Boilers Model 4WI Manual...
Page 62: ...Waterside Care and Requirements 3 16 750 211 revised 2009 Promethean Boilers Model 4WI Manual...
Page 70: ...Sequence of Operation 4 8 750 211 revised 2009 Promethean Boilers Model 4WI Manual...
Page 114: ...Adjustment Procedures 6 28 750 211 revised 2009 Promethean Boilers Model 4WI Manual...
