Help required

[switch10]

Hi all so I generally carry out domestic works and small commercial works and now I’m going for my assessment for commercial works 3phase with NICEIC .

now I have found a small new job which I can use for my assessment but need to make sure I get everything spot on .

so I’m ok with all circuit cables etc but here’s something I haven’t yet had to do before .

unit has a 3 phase supply coming into it and electric supply com Sony has requested meter tails be installed from supply to meter location prior to there visit and also meter tails from meter location to distribution board .

now developers of the new site have stated 125kva minimum , 

but having only done domestic 25mm before I’m not sure what size meter tails to come from supply side to meter and from meter to distribution Board based on 125kva ,  as stated this is 3 phase retail shop .

Can someone help?

 

[binky]

is that 125kva total or per phase?

 

[ProDave]

Assuming 125kVA total that will be 200A per phase then.

Don't present them with a domestic CU and domestic tails.

 

[Andy™]

probably getting a 200a service head for that. probably going to need 70 or 95mm for the tails

fit a schneider KQ board, there designed for 250a as standard, just make sure you use a 250a switch and not a 125a

 

[kerching]

You may also find that at that size they will want to fit CT metering and not Whole Current, they may have a spec for the cable type .  around here they like TriRated and get all happy and excited when they see it. However if you fit 70/95 solid strands( think BIG 6491x ) they go all sulky

 

[Andy™]

if its not in containment i usually use H07RNF singles. far easier to work with

 

[kerching]

...and another thing to note 

quite often they want you to supply the cable lugs AND the crimping tool,for THEM to use,!

 

[Andy™]

well they arent going to do any work themselves now are they?

 

[switch10]

Well this is where I’m confused as to be fair the customer only has 3 phase circuit going in the rest are just lights and sockets and a couple of spare ways for anything additional in the future so no massive spec , but the supplier has written this on the supply 

Well this is where I’m confused as to be fair the customer only has 1 x 3 phase circuit going in the rest are just lights and sockets and a couple of spare ways for anything additional in the future so no massive spec , but the supplier has written this on the supply 

 So would you say that’s 200amp per phase would you say from what they have written on there? 

 

[Andy™]

Well this is where I’m confused as to be fair the customer only has 3 phase circuit going in the rest are just lights and sockets and a couple of spare ways for anything additional in the future so no massive spec , but the supplier has written this on the supply 

View attachment 11566

id expect they will be fitting a meter to the side of that with CT coils around the conductors coming into the top. a bit 100x100 galv trunking on top of that then into your DB would work well

 

[kerching]

200/5 almost certainly refers to the CT ratios

CT testing point is the black box to the side

But this is guesswork,as I have not seen that type of head around here before

 

[switch10]

probably getting a 200a service head for that. probably going to need 70 or 95mm for the tails

fit a schneider KQ board, there designed for 250a as standard, just make sure you use a 250a switch and not a 125a

Yes this is the board I’ve purchased along with the 250a disconnector add on for board . 
 

just tails that’s puzzling me as will only be in a short length of 100x 100 galv trunking I’m wondering weather to go with 70mm or 90mm tails 

 

[Andy™]

just tails that’s puzzling me as will only be in a short length of 100x 100 galv trunking I’m wondering weather to go with 70mm or 90mm tails 

and what does table 4D1A say for the current capacity of 70 & 95mm for your reference method?

 

[switch10]

and what does table 4D1A say for the current capacity of 70 & 95mm for your reference method?

Well would have to be 95mm as will be enclosed in trunking - but round here we have big problems with meter companies saying they can’t terminate into meters with that size cable , so just worried I install 95mm which is expensive then they come along and won’t connect to meter Because they say cables to big 

 

[binky]

Well would have to be 95mm as will be enclosed in trunking - but round here we have big problems with meter companies saying they can’t terminate into meters with that size cable , so just worried I install 95mm which is expensive then they come along and won’t connect to meter Because they say cables to big 

this may help

 

[switch10]

What is that a picture off binky? Sorry not seen that before? Would you have a link?

 

[Andy™]

pin crimp. makes the overall diameter smaller so they fit into terminals. a lot of the terminals are bolted though and need ring terminals

https://www.superlecdirect.com/cables-and-accessories-c1/uninsulated-crimp-pins-s219090944/

 

[switch10]

pin crimp. makes the overall diameter smaller so they fit into terminals. a lot of the terminals are bolted though and need ring terminals

https://www.superlecdirect.com/cables-and-accessories-c1/uninsulated-crimp-pins-s219090944/

Thank you for this 

 

[poni]

we have big problems with meter companies saying they can’t terminate into meters with that size cable ,

but are you not having CTs Fitted ,the tails through the CT into the head ,and the CT connects to the meter using a smaller cable (normally 1.5 or 2.5)

 

[switch10]

but are you not having CTs Fitted ,the tails through the CT into the head ,and the CT connects to the meter using a smaller cable (normally 1.5 or 2.5)

 All I’ve been asked to do is to supply and install tails into the service head - and for these to be terminated before meter installation date - that’s the exact details I’ve got from customer