Testing Gas Valve; Checking Main Burners; Checking Orifices - Daikin DCG Series Service Instructions Manual

SERVICING
3. Touch one probe of the ohmmeter to the motor frame
(ground) and the other probe in turn to each lead.
If the windings do not test continuous or a reading is obtained
to ground, replace the motor.
4. After completing check and/or replacement of induced
draft blower motor.
5. Turn on electrical power and verify proper unit operation.
S-304 TESTING GAS VALVE
Direct Spark Ignition (DSI) Systems
TWO STAGE MODELS ONLY: A two-stage combination
redundant operator type gas valve which provides all manual
and automatic control functions required for gas fired heating
equipment is used.
The valve provides control of main burner gas flow, pressure
regulation, and 100 percent safety shut-off.
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing this unit. Multiple power
sources may be present. Failure to do so
may cause property damage, personal injury
or death.
1. Ensure gas valve and main gas supply are on.
2. Using a voltmeter, check from C and M on gas valve for 24
volts to gas valve.
3. If 24 volts are present and no gas flows through the valve,
replace valve.
Regulator Cover Screws
(Reg. Adj. Beneath these screws)
INLET
Gas Valve
On/Off Switch
66
High Fire
Adjust
Low Fire
Adjust
OUTLET
36H54
PRESSURE ADJUSTMENTS
S-305 CHECKING MAIN BURNERS
The main burners are used to provide complete combus-
tion of various fuels in a limited space, and transfer this heat
of the burning process to the heat exchanger.
Proper ignition, combustion, and extinction are primarily
due to burner design, orifice sizing, gas pressure, primary
and secondary air, vent and proper seating of burners.
BECKETT BURNER
WARNING
Disconnect gas and electrical power supply.
In checking main burners, look for signs of rust, oversized
and undersized carry-over ports restricted with foreign
material, etc.
S-306 CHECKING ORIFICES
A predetermined fixed gas orifice is used in all of these
furnaces. That is an orifice which has a fixed bore and
position.
A
GAS
STREAM B