A while ago I moved into a house built in 1960. I'm not entirely happy about the wiring configuration which is quite complex. It's as follows.
Fused 60A TT supply (odd that as it's underground not o/hd and the substation is 50 metres away) comes into the detached garage. Two tails go to the meter and from the meter to a consumer unit. Earthing is by a wire which disappears through the garage floor, presumably to a rod, but I can't find the rod connection point outside. This wire is bare 7/.029 (corresponds to 2.8 sq mm for youngsters) from the earth bar in the CU.
The CU has a mains in switch that feeds a 63A MCB and a 30mA RCD, in turn feeding a 16A and a 6A MCB for garage sockets and lights (radial).
The 63A MCB supplies 2 core 3/16" (16 sq mm approx) PVC over copper sheathed Pyrotenax which goes about 30 metres to the house. The copper sheath is used as the earth.
At the house the Pyro goes into a split load CU with power on a 30mA RCD and lights not on RCD, and various MCBs. The pyro sheath goes to the earth bar in the CU. There is no other earthing i.e. not another rod.
The gas meter is external on the house wall, the gas pipe is bonded on entry to the house with 10 sq mm insulated back to the CU earth bar. The water pipe is bonded on entry, back to the CU earth bar, with bare 7/.036 (i.e. about 6 sq mm).
A 16A MCB, protected by the RCD, feeds an SWA cable going to a wooden stable outside. At the stable there is a small CU with switch and 2 MCBs for lights and sockets (1 radial). Earthing is by 1 core and armouring of the SWA, no rod.
I've toyed with the idea of asking if I can go onto PME but I can see complications! In particular I can't take continuous gas and water bonding back to the incoming supply. I think the best option I can take is to improve my TT earthing with new rod(s) and a 16mm earth cable at the garage to current standards. In effect then the house would be supplied TN-S from the garage and the stable TN-S from the house I think? Or should I rod the house and the stable as separate TT's with no links between them?
I'd appreaciate really expert comments please! I've been qualified in the past but I'm not fully up with current regs.
Thanks
Mike
Fused 60A TT supply (odd that as it's underground not o/hd and the substation is 50 metres away) comes into the detached garage. Two tails go to the meter and from the meter to a consumer unit. Earthing is by a wire which disappears through the garage floor, presumably to a rod, but I can't find the rod connection point outside. This wire is bare 7/.029 (corresponds to 2.8 sq mm for youngsters) from the earth bar in the CU.
The CU has a mains in switch that feeds a 63A MCB and a 30mA RCD, in turn feeding a 16A and a 6A MCB for garage sockets and lights (radial).
The 63A MCB supplies 2 core 3/16" (16 sq mm approx) PVC over copper sheathed Pyrotenax which goes about 30 metres to the house. The copper sheath is used as the earth.
At the house the Pyro goes into a split load CU with power on a 30mA RCD and lights not on RCD, and various MCBs. The pyro sheath goes to the earth bar in the CU. There is no other earthing i.e. not another rod.
The gas meter is external on the house wall, the gas pipe is bonded on entry to the house with 10 sq mm insulated back to the CU earth bar. The water pipe is bonded on entry, back to the CU earth bar, with bare 7/.036 (i.e. about 6 sq mm).
A 16A MCB, protected by the RCD, feeds an SWA cable going to a wooden stable outside. At the stable there is a small CU with switch and 2 MCBs for lights and sockets (1 radial). Earthing is by 1 core and armouring of the SWA, no rod.
I've toyed with the idea of asking if I can go onto PME but I can see complications! In particular I can't take continuous gas and water bonding back to the incoming supply. I think the best option I can take is to improve my TT earthing with new rod(s) and a 16mm earth cable at the garage to current standards. In effect then the house would be supplied TN-S from the garage and the stable TN-S from the house I think? Or should I rod the house and the stable as separate TT's with no links between them?
I'd appreaciate really expert comments please! I've been qualified in the past but I'm not fully up with current regs.
Thanks
Mike