Monessen Hearth DEB30, DEB20 manual Electrical Wiring Milli-Volt, Operation Of Thermostat Sensor

ELECTRICAL WIRING (MILLI-VOLT)

OPERATION OF THERMOSTAT SENSOR

1.Follow millivolt lighting instructions on lighting plate attached to unit or in homeowner’s manual.

2.With control knob in the “ON” position make sure the ON/OFF switch is in the “OFF” position. See Figure 24.

3.The unit is now being controlled by the thermostat sensor. The sensor will now cycle the burners on and off. You can adjust how often the unit cycles by turning the control knob on the sensor.

ON/OFF

Switch

Control

Knob

THE

SERMOS

TTINGTAT

HIGH

2
6D33
17	LOW

T-Stat

Sensor

Figure 24 - Control Knob in “ON” Position and ON/OFF Switch in “OFF” Position

CHECKING SYSTEM OPERATION

The milli-volt system and individual com- ponents may be checked with a milli-volt meter having a 0-1000 mV range. Conduct each check shown in chart below by con- nection meter test leads to terminals as indicated.

		CONNECT
CHECK	TO	METER	THERMOSTAT	METER
TEST	TEST	LEADS TO	CONTACTS	READING
		TERMINALS		SHOULD BE
A	COMPLETE	TP/TH and TH	CLOSED	MINIMUM
	SYSTEM			175
B	THERMOPILE	TP and TP/TH	OPEN	MINIMUM
	OUTPUT			500

A.COMPLETE MILLI-VOLT SYSTEM CHECK

(“A” Reading - Thermostat contacts CLOSED - Control Knob “ON” - Main burner should turn ON)

a.If the reading is more than 175 milli-volts and the automatic valve still does not come on, replace the control.

b.If the closed circuit reading (“A” reading) is less than 175 milli-volts, determine cause for low reading, proceed to Section B below.

B.Thermopile Output Reading Check

(“B” Reading - Thermostat contacts OPEN - Main burner OFF)

1. Check gas pressure to the unit. If gas pressure is within minimum and maximum on data plate, then check pilot voltage, 500 milli-volts minimum. If the minimum milli-volt reading is not obtainable, replace pilot.

44D0060 25