Miller Electric Big Blue 400 PX manual Troubleshooting, Welding, Standard Generator Power

8-11. Troubleshooting

. Also see Voltmeter/Ammeter help displays to assist in troubleshooting weld problems (see Section 8-10).

Engine speed is controlled by an electronic governor and throttle actuator. Governor adjustment should only be done by a Factory Authorized Service Agent.

A. Welding

Trouble		Remedy
No weld output; generator power output		Place Process/Contactor switch in a Weld Terminals Always On position, or place switch in a Remote
okay at ac receptacles.		On/Off Switch Required position and turn remote contactor on (see Section 6-4).
		Reset supplementary protector CB8 (see Section 8-9). Check for faulty remote device connected to
		RC14.
		Check and secure connections to Remote Control receptacle RC14 (see Section 5-9).
		Check Voltmeter/Ammeter help displays (see Section 8-10).
No weld output, or generator power out-	Disconnect equipment from generator power receptacles during start-up.
put at ac receptacles.
		Reset supplementary protector CB3. (see Section 8-9).
		Check fuse F1, and replace if open (see Section 8-9). If F1 is open, have Factory Authorized Service
		Agent check the voltage regulator module PC3.
		Check Voltmeter/Ammeter help displays (see Section 8-10).
		Have Factory Authorized Service Agent check brushes and slip rings, voltage regulator module PC3, and
		field excitation circuit.
Erratic weld output.		Check and tighten connections inside and outside unit.
		Be sure connection to work piece is clean and tight.
		Use dry, properly stored electrodes.
		Remove excessive coils from weld cables.
		Have Factory Authorized Service Agent check brushes and slip rings.
High weld output.		Have Factory Authorized Service Agent check main control module PC1 and hall device HD1.
Low weld output.		Check engine speed, and have Factory Authorized Service Agent adjust if necessary.
		Check fuse F1, and replace if open (see Section 8-9). If F1 is open, have Factory Authorized Service
		Agent check the slip rings and brushes, rotor, and voltage regulator module PC3.
Low open-circuit voltage.		Check engine speed, and have Factory Authorized Service Agent adjust if necessary.
		Have Factory Authorized Service Agent check main control module PC1, voltage regulator module PC3,
		and main rectifier.
No remote fine amperage control.		Repair or replace remote control device.
		Check and secure connections to Remote Amperage Adjust receptacle RC14 (see Section 5-9).
No 24 volt ac output at Remote recep-	Reset supplementary protector CB8 (24 volt) (see Section 8-9).
tacle RC14.
B. Standard Generator Power

Trouble	Remedy
No generator power output at ac recep-	Reset receptacle circuit protectors (see Section 7-1).
tacles; weld output okay.
No generator power or weld output.	Disconnect equipment from generator power receptacles during start-up.

OM-223 037 Page 41