Miller Electric OM-842 - Manuel (Page 48)

OM-842 Page 44
J. Background Relay Test
This procedure tests the internal dc background current
source.
1. When the repeating test displays are shown (see Sec-
tion 7-2C), press Right/Increase or Left/Decrease until
the display shows:
B A C K G R O U N D
R E L A Y T E S T
2. Press Parameter Select to begin the test. This ener-
gizes the background relay. The display shows:
C H E C K V O L T M E T E R F O R
4 2 T O 5 4 V O L T S D C
3. The Voltage meter on the control unit should indicate a
voltage within the specified range.
If an acceptable voltage is not indicated, contact the
nearest Factory Authorized Service Station/Service
Distributor.
4. When the background relay tests okay, press Parame-
ter Select to deenergize the relay and exit the test. Use
the Right/Increase or Left/Decrease push button to ac-
cess another test, or stop the diagnostics program.
K. Gas Solenoid Relay Test
This procedure tests the gas solenoid relay. Indirectly, the gas
solenoid is also tested.
1. When the repeating test displays are shown (see Sec-
tion 7-2C), press Right/Increase or Left/Decrease until
the display shows:
G A S S O L E N O I D
R E L A Y T E S T
2. Press Parameter Select to energize the gas solenoid
relay. The display shows:
G A S S O L E N O I D R E L A Y
I S E N E R G I Z E D
3. If gas flows, the gas solenoid relay and gas solenoid
are working correctly. In this case, go to Step 4.
If gas does not flow, contact the nearest Factory Autho-
rized Service Station/Service Distributor.
4. When the gas solenoid relay tests okay, press Parame-
ter Select again to deenergize the relay. The program
automatically returns to the repeating test displays.
Use the Right/Increase or Left/Decrease push button
to access another test, or stop the diagnostics pro-
gram.
L. Arc Starter Relay Test
This procedure tests the arc starter relay. Indirectly, the Arc
Starter Board PC8 is also tested.
1. When the repeating test displays are shown (see Sec-
tion 7-2C), press Right/Increase or Left/Decrease until
the display shows:
A R C S T A R T E R
R E L A Y T E S T
2. Press Parameter Select to energize the arc starter
relay. The display shows:
A R C S T A R T E R R E L A Y
I S E N E R G I Z E D
3. If a crackling sound can be heard inside the welding
power source, the relay is working correctly. In this
case, go to Step 4.
If a crackling sound is not heard inside the welding
power source, contact the nearest Factory Authorized
Service Station/Service Distributor.
4. When the relay tests okay, press Parameter Select
again to deenergize the relay. The program automati-
cally returns to the repeating test displays. Use the
Right/Increase or Left/Decrease push button to access
another test, or stop the diagnostics program.
M. User Relays
This procedure tests the user relays (see Section 2-3). Since
the procedure is the same for each of the user relays, one ex-
ample is presented that applies to all the user relays.
1. When the repeating test displays are shown (see Sec-
tion 7-2C), press Right/Increase or Left/Decrease until
the display shows the test display for the desired relay.
For example, if the initial time relay is being tested, the
display would show:
I N I T I A L T I M E
R E L A Y T E S T
2. Press Parameter Select to begin the test. The display
shows:
I N I T I A L T I M E R E L A Y
I S E N E R G I Z E D
After a short pause, the relay energizes.
3. Use a suitable VOM (volt-ohmmeter) to check the re-
sistance across the relay terminals as shown in
Figure 7-1.