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Old Iron Underground Gas Pipe Earthing.

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I came upon this installation today. There is no P.M.E. earth terminal but just a TT rod outside. Ze is about 15 Ohms. But even accounting for the rain recently I can not see that a single 4ft. rod can achieve that low a Ze. The old Denso tape covered iron gas pipe runs underground to the road. It is bonded inside the house as is (presumably) the water pipe. The house is a 1930s aged property. I am noy happy about the final circuits in the consumer unit that do not have R.C.D. protection. Some of these supply outside metal lights on the bungalow wall. I can't imaging in the 80s or 90s this arrangement ever complying. Is the installation relying on the old gas pipe as an earth electrode? I could not do a thorough test today as the gas man was servicing the gas boiler.

Comments please?

Parents
  • +1

    There is another point Z and that is that bonding to the incoming Iron mains may have given a reasonable figure and the regulations "rely" may well have been missed, and the latest wiring was probably done by someone who didn't do any testing and was blind and stupid, so you get the situation you found. As I said, fairly common around here.

Reply
  • +1

    There is another point Z and that is that bonding to the incoming Iron mains may have given a reasonable figure and the regulations "rely" may well have been missed, and the latest wiring was probably done by someone who didn't do any testing and was blind and stupid, so you get the situation you found. As I said, fairly common around here.

Children
  • 0 in reply to David Stone

    Quote. "And since diesel engines require more powerful engine starters, you can expect to use over 500 amps to jump-start a small diesel engine."

    We are only looking at four times the average current needed to jump start a small diesel engine when the battery is flat. And we use pretty poor foreign made clamps for that. So good quality earthing clamps should be able to carry 2,000 Amps for 5 seconds. They may get a bit warm but they will not fail.

    Z.

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