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cable resistance

Wednesday 25 July 2018

Here's an interesting one. I got this compressor for painting my car, as it happens I'm not going to use it. All the mixing of chemicals put me off, too much like chemistry. Anyway it has other uses like blowing dust away, sand blasting and blowing up tyres. My garage is some distance from the house so I have to use two connected extension cables to connect to the mains electricity. Everything seems to work OK but the other day I used the compressor to sandblast a grill and connected it directly to the house socket. Everytime I switched it on it tripped the switch. It seems that the extra resistance of the extension leads reduce the current enough to stop this happening in the garage. Maybe all my electrical appliances are running under power? Might explain why my drill is so weak.

19 Jul 2018

Comments 1

Keith Irvine 10 August 2018 - 01:55

Because of the increased voltage drop in your cables the compressor motor does not receive the full 230V with a consequent reduction in back emf. The difference between the forward and back emf’s has now increased and more current is drawn from the supply. This is why the cut-out trips.
For spray painting it is better to go the airless way.

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