PAT test guidance

[gridrunner]

Hello everyone,

some of you might have seen this thread in the tomb-like uk-vac email list and on ukpinball, but the PAT testers have been back to my cabs in the works gamesroom. This is what I've had:

Cruisin (it's a world stand up)

failed on insulation resistance, should be below 0.1ohm but is reading 0.18ohm on the main earth terminal. suggest removing redundant earth cables and make others as short as possible.

area 51

failed on insulation resistance, should be below 0.1ohm is reading 0.11ohm. suggest shortening earth cables to lower resistance.

I'm a bit confused about what this test is going on about. I did add earthing to both cabs following and earlier test were both cabs failed on earth bonding. In particular I added an earth from the area 51's AT PSU case to the cab ground point and hooked up the coin doors. For the cruisin I fixed one missing cable on the CP and re-checked everything else. The cruisin is especially puzzling because it's nice and clean inside and looks like new (the outer cab has been in the wars a bit though).

Can anyone help with any pointers and explain what this test is trying to establish?

thanks guys!

 

[gridrunner]

Hi guys,

I'd figured I'd update this post as after cornering the in house electrician for most of the afternoon, I managed to pass all the games.

Area 51 got through by adding an earth wire with a good bond, from the AT PSU to the earthing plate on the cab. The inline filter and mains switch/inlet was replaced and the cable between it and the power supply itself was shortened.

The Cruisin had higher than acceptable resistance between the earth conductor and the ground plate because of a dodgy molex connector that connected the transformer to mains in. Shortening several of the earth wires and replacing this molex with a chocolate block cured the high resistance and the game passed.

Please ignore the previous resistance values, they are bollocks. The resistance should be 1 megahom or lower for the insulation resistance test. any higher and it's a fail. The tester classed the cabs as IT equipment and this was the only test run.

gridrunner2011-01-22 00:23:00