Hobart Hobart - GPU-600 GPU-600

- Check fan thermostat operation

- Use SAE-20 or 10W30 electric motor or automotive oil. Do not use definite purpose oils such as those for sewing machines, cleaning, rust preventative, or cutting applications.

- Use 10 – 15 drops per end (approximately 1.0 cc or 1/8 teaspoon). Do not over oil.

- Figure 3 , p.54 shows a tube extending upward from the rear bearing. The front bearing has a similar tube. Use these tubes to oil the bearings.;

a) Turn off the input power at the source. Make sure that the power cannot be inadvertently turned back on.

c) Disconnect the three AC input leads at the terminals on the input contactor and the grounding wire at the grounding lug.

d) Loosen the cable clamp on the rear of the GPU and remove the input cable from the clamp.

e) Disconnect the output cable from the output contactor (+) and the ammeter shunt (-).

f) Loosen the cable clamp at the base and remove the output cable from the GPU.

g) If the unit is a bridge mount unit, also disconnect and remove the remote control cables.

h) If the unit is bridge mount or fixed mount, attach a lifting hoist or forklift to the bottom of the GPU and remove the mounting screws or bolts that attach the GPU to its mounting.

Inspect and clean general (severe duty)

Turn off input power at the source. Make sure that power cannot be inadvertently turned back on.

a) Using compressed air or a soft brush, clean any dirt and debris from the interior.

b) Inspect terminal blocks for evidence of overheating due to loose electrical connections.

c) Inspect electrical and mechanical connections for tightness.

d) Remove the front panel screw that holds the circuit board panel. Swing the circuit board panel out to the side.

e) Inspect the circuit board for evidence of overheating, such as burned components.

f) Inspect the hinge for the circuit board panel. If this hinge sticks or is difficult to operate, spray the hinge with a silicone spray lubricant.

g) Inspect all wiring, leads, and cables. Inspect for cuts, abrasions, and signs of deterioration and overheating. Inspect the leads for broken strands and terminals.

h) Inspect the output contactor. If the contacts are badly burned, the contactor should be replaced as soon as possible. Slightly pitted and burned contacts can be cleaned up with a commercial contact cleaner and very fine-grained emery cloth or equivalent.