Determining CSA of tails and sub mains

[atm84]

So how do you guys determine the size of existing tails and sub main conductors when carrying out EICR or surveys.

The reason I ask is, today I have been looking through some EICR and the conductor size stated of some of tails and sub mains is different to what I thought just by having a quick glance.

I know experience takes a big part but insulation on the conductors can vary from manufacturers.

Has anyone used insulated calipers? Can you even get them?

 

[HappyHippyDad]

I carry a pair of calipers and have a list of all the CSA's written down for all sizes of cable.

However I do remember a thread in the not too distant past when Mr Richard Burns suggested taking a small sample of each of the conductors, crimping on a ring lug connector and popping on a keyring. I thought that was quite inventive, haven't done it though :smiley2:

 

[Silly Sausage]

However I do remember a thread in the not too distant past when Mr Richard Burns suggested taking a small sample of each of the conductors, crimping on a ring lug connector and popping on a keyring. I thought that was quite inventive, haven't done it though :smiley2:

I remember that and how the dinosaurs ripped the proverbial out of us!

 

[Andy78]

I have popped lugs over conductors in the past to make sure. It's 25mm and 35mm SWA that always seems to make me second guess myself.

 

[atm84]

I have popped lugs over conductors in the past to make sure. It's 25mm and 35mm SWA that always seems to make me second guess myself.

I agree. It always 25mm and 35mm that gets me. I'm thinking of visual inspection when circuits are still live, hence can't fit lugs over them.

 

[Andy78]

I agree. It always 25mm and 35mm that gets me. I'm thinking of visual inspection when circuits are still live, hence can't fit lugs over them.

If you are looking at just insulation and sheathing then it's a lot harder job, especially if you take into account the huge variation in cable sheath and insulation thicknesses seen in the last decade.

 

[shanky887614]

If you are looking at just insulation and sheathing then it's a lot harder job, especially if you take into account the huge variation in cable sheath and insulation thicknesses seen in the last decade.

there is a lot of insulation.

look at 9218 belden for example

If you are looking at just insulation and sheathing then it's a lot harder job, especially if you take into account the huge variation in cable sheath and insulation thicknesses seen in the last decade.

there is a lot of insulation.

look at 9461 belden for example is 0.18" thick but the core size is 22AWG

i think it converts to around 4.5mm and 0.32mm

 

[leeobrien]

I went into our regular wholesalers with a pair of calipers and measured the sheaths of as many as I could find, obviously noting down the CSA for each measurement....I know its by no means conclusive, but its a good start.

 

[D Skelton]

So how do you guys determine the size of existing tails and sub main conductors when carrying out EICR or surveys.

The reason I ask is, today I have been looking through some EICR and the conductor size stated of some of tails and sub mains is different to what I thought just by having a quick glance.

I know experience takes a big part but insulation on the conductors can vary from manufacturers.

Has anyone used insulated calipers? Can you even get them?

Experience really, however I still struggle to tell the difference between a 120mm and a 150mm and I also struggle to tell the difference between a 150mm and a 185mm. Calipers around one of the strands will always tell me though. It's never 100% accurate as the strands are shaped but an average value taken from a couple of measurements will be near enough to tell the difference.

 

[GMES]

I always find 150mm 4 core the easiest, because it's the same thickness as my............. Answers on a post card please!