Miller Electric 12VS manual Troubleshooting

6-3. Troubleshooting

	Trouble	Remedy
Wire does not feed; open-circuit voltage		Check circuit breaker CB1. Reset CB1.
available.
		Unit overheated. Allow unit to cool.
		Check sensing lead connection.
		Check gun trigger plug connection.
		Check gun trigger. See gun Owner’s Manual.
		Have Factory Authorized Service Agent check Control board PC1.
Wire feeds erratically.		Readjust hub tension.
		Readjust drive roll pressure.
		Clean or replace dirty or worn drive roll (see Section 4-4).
		Remove weld spatter around nozzle opening.
		Replace contact tip or liner. See gun Owner’s Manual.
		Change to correct size and type drive roll (see Section 4-4)
		Incorrect size or worn wire guides (see Section 4-4)
		Check wire drive motor brushes.
		Have Factory Authorized Service Agent check control board PC1.
Motor runs slowly.		Check and replace contact tip or liner if necessary.
		Have Factory Authorized Service Agent check Control board PC1.
		If soft start is not on, motor will switch to slower speed if current is not sensed by HD1.
		When soft start is on, motor will run slow until weld current is sensed by HD1.
Unit does not switch out of Soft Start.		Check transducer HD1 and connections, and replace if necessary.
Wire feeds when Jog switch is pressed		Check gun trigger connection at wire feeder. Check gun trigger leads and trigger switch. See gun Owner’s
but not when gun trigger is pressed.		Manual.
		Have Factory Authorized Service Agent check Control board PC1.
Wire stubbing on low end using a con-		Make sure CC/CV switch is in CC position (see Section 5-1).
stant current power source or feeder re-
sets.
		Increase power source inductance setting if available.
		Increase output setting of power source or decrease wire feed speed.
Gas does not flow or does not stop flow-		Check gas valve.
ing; wire feeds.
		Check coil voltage and connections of gas valve GS1. Check continuity of coil. Replace GS1 if necessary.
		Have Factory Authorized Service Agent check Control board PC1.
		Clear blockage in gas hose or replace hose.
		Clear blockage in welding gun.
Wire remains energized after trigger is		Check contactor W1 to see if contacts are frozen closed.
released.
Gun trigger is pressed, gas does not		If a welding arc is not established in 3 seconds, after the gun trigger is activated, the unit will feed wire
flow, wire is not energized, wire feeds.		without energizing the contactor or gas valve. If the gun trigger is still activated after two minutes, the wire
		will stop feeding. This is to prevent complete despoolling of the wire, as in the case of a damaged gun.

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