Hi guys, I have come across two problems today well acutely three so I will list them first..
1st
Testing a 4mm radial circuit today or so I thought! I asked the young lad to go to the end of line and take an r1+r2 reading. When he opened up the last point he said that there were four 2.5 cables in the socket two netrals and two lives, I first thought I had made a mistake and check to make sure that the circuit was indeed a rad and not a ring. No problem there. I then thought he must have the wrong circuit but a quick live test proved it was the correct circuit.
I then started to look at the causes, It turns out the the 4mm was feeding a 20amp double pole sw and from there they had used 2.5mm conductors so I presume they had run out of 4 mm so double up on 2.5! I have seen this done on site temps but never on a new install. now you can see the confusion it caused me so it is clearly bad practice. But my question is it against the regs???
2nd
Found really badly wired contactors, I won't bore you with all the details but there were four contactors all being controlled by a time clock (nothing wrong there) there was only 3 lights on two circuits and 4 on the other two( Nothing wrong there) Just trying to give you a feel for the circuits and what they are controlling.
Like I said I don't want to go into all the wiring problems but I do have a question, the neutrals on the lights were wired through the contactor, so the contactor is effectively acting as a double pole switch. Can someone tell me is this standard practice to wired the neutral through the contactor. I have been told that were automatic disconnection of supply takes place both conductors must be switched. This seem unnecessary to me as the contactor is merely acting as switch. The contactors are really old and while testing I was getting a great smell of burning I have yet to work out if this is from the coil or the load current through the contacts( testing on going circuit out of use) I just think if the neutral contact burns out then I will have a neutral conductor O/C and sitting at mains voltage. What is common practice and what does the regs say? will look when I have time but if some one has the answer all the better.
3rd
keep this short and sweet
testing a three phase sub main to a remote DB. when looking for the DB (poor description of location) could not find DB with new phase colour cable. physically traced cable up in to the loft where we found the cable had been jointed trough an adaptable metal box and then though crimped and insulated with electrical tape! to an existing cable's with old colours. Yet again lack of information and bad practice led to confusion and could lead to a highly dangerous situation. Thoughts on this one please.
Look forward to your replies tomorrow.
1st
Testing a 4mm radial circuit today or so I thought! I asked the young lad to go to the end of line and take an r1+r2 reading. When he opened up the last point he said that there were four 2.5 cables in the socket two netrals and two lives, I first thought I had made a mistake and check to make sure that the circuit was indeed a rad and not a ring. No problem there. I then thought he must have the wrong circuit but a quick live test proved it was the correct circuit.
I then started to look at the causes, It turns out the the 4mm was feeding a 20amp double pole sw and from there they had used 2.5mm conductors so I presume they had run out of 4 mm so double up on 2.5! I have seen this done on site temps but never on a new install. now you can see the confusion it caused me so it is clearly bad practice. But my question is it against the regs???
2nd
Found really badly wired contactors, I won't bore you with all the details but there were four contactors all being controlled by a time clock (nothing wrong there) there was only 3 lights on two circuits and 4 on the other two( Nothing wrong there) Just trying to give you a feel for the circuits and what they are controlling.
Like I said I don't want to go into all the wiring problems but I do have a question, the neutrals on the lights were wired through the contactor, so the contactor is effectively acting as a double pole switch. Can someone tell me is this standard practice to wired the neutral through the contactor. I have been told that were automatic disconnection of supply takes place both conductors must be switched. This seem unnecessary to me as the contactor is merely acting as switch. The contactors are really old and while testing I was getting a great smell of burning I have yet to work out if this is from the coil or the load current through the contacts( testing on going circuit out of use) I just think if the neutral contact burns out then I will have a neutral conductor O/C and sitting at mains voltage. What is common practice and what does the regs say? will look when I have time but if some one has the answer all the better.
3rd
keep this short and sweet
testing a three phase sub main to a remote DB. when looking for the DB (poor description of location) could not find DB with new phase colour cable. physically traced cable up in to the loft where we found the cable had been jointed trough an adaptable metal box and then though crimped and insulated with electrical tape! to an existing cable's with old colours. Yet again lack of information and bad practice led to confusion and could lead to a highly dangerous situation. Thoughts on this one please.
Look forward to your replies tomorrow.
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