Why is it that some LG Dryer Service Manuals mention 90v AC at the Gas Valve Coils, and other LG Dryer Service Manuals mention 90v DC at the Gas Valve Coils ?
With the same Gas Valve part numbers.
Okay--checking the most recent training manuals has confirmed your sharp observations Regus...
All LG dryer gas valve coil assemblies (part # 5221EL2002A) use 90 volts DC current fed from the MAIN BOARD.
Some manuals did indeed have an *incorrect* (typo) troubleshooting flow-chart listing the voltage incorrectly as AC.
The correct sequence of operation for GAS HEAT operation is as follows:
1) FLAME SENSOR must be *closed* (closes at 320F)
2) COIL no. 01 is energized (90 VOLTS DC)
3) IGNITOR is energized & glows (120 volts)
4) FLAME SENSOR opens (370F) & IGNITOR turns off
5) COIL no. 02 is energized (90 VOLTS )---Flame Ignites.
I may start calling you EAGLE EYES Regus--that's an impressive observation on your part---and a glaring error on my end:)
Just to be absolutely certain---I pulled a new GAS VALVE COIL ASSY out of a box to check the label--103 DC.
This means that with a meter set to DC voltage---it should indicate 90 to 103 VOLTS DC on either coil # 01 or 02.