periodic queries..

[tigerpaul]

Hello fellas,

When doing periodic inspections, what do you think is the best method of estimating the size of conductors? That is meter tails, and earthing conductors.

Some of the older conductors are a lot thicker than the newer ones, and it is difficult to estimate what the real size is.

 

[needasparks]

Think this is something that you pick up in time, bear in mind it is only the insulation that varies on some so getting a good look at the copper conductor itself is best. You can sometimes tell by seeing how easy/hard bending it is. This only works on 16/25/35 tails, on the bigger ones they tend to be lugged so have a look at the size stamped on them may help. We all struggled with this one i'm sure but it will get easier with time. The more you install them, the more of a feel you get when dressing them will help.

 

[tigerpaul]

Yeah, i always look along the side for any text, the newer ones have the size printed on sometimes.
I've also got a selection of crimp lugs which I hold up and try to compare with the conductor.

The meter tails are the most difficult though as they are live and I cannot get to either end, so its always a bit of a guess.

 

[Richard Burns]

Have some example lengths of known cable on a key ring or sheet of card to compare to, when you change out an old cable micrometer it and add it to the selection with the size.

 

[needasparks]

Yeah, i always look along the side for any text, the newer ones have the size printed on sometimes.
I've also got a selection of crimp lugs which I hold up and try to compare with the conductor.

The meter tails are the most difficult though as they are live and I cannot get to either end, so its always a bit of a guess.

Yes I know what you mean, I find 25/35 the most difficult to judge as i found quite a bit of 35 installed during the seventies. When i said stamped on it, i meant on the lug itself ie A2 etc. but as you say, they will be live and normally if it is lugged the nut covers it up. This is what i do on the larger installs when its over 100A. the 70/95mm look very similar sometimes.
Richards idea is a good one to keep some samples. If you cannot verify a size 100% you will have to make a note of this on any certificate with further investigation required .

 

[Deleted member 26818]

I just guess.

 

[needasparks]

I just guess.

Toy'd with putting that but thought someone else should pull the trigger.

''Good man Spin, taking the bullet for the team''

 

[Goody]

Just as Richard Burns says, I carry an inch or two of the most usual sized cables in my meter box to help me assess the cable type when I do CU changes or anything else for that matter.