60a main fuse??

[gpz900jim]

Hi, I am doing a rewire at the moment. Adding all of the breakers up and dividing by 0.4, gives me a total load of 71a. I will be upgrading the meter tails to 25mm and the main earth to 16mm.. The main fuse is 60a. My questions are;1 how would I go about getting the main fuse uprated? or can I note on the EIC that the main fuse is too small and recommend that the customer gets it uprated ? 2 I need to change the tails from the main fuse up to the meter, and from the meter to the cu. Will the supplier have to come along and fit the meter tails and reseal, or shall I just cut the seal on the meter and just say there wasnt one there at all? There is currently no seal on the main fuse. I know what I should do, but is the real world different ie, what would you do??

 

[ukpablo]

firstly, add up the ccts and multiply by 0.4 to give u a rule of thumb figure for diversity. (otherwise 0.4 x 71A gives a starting total load of 28.4A.......this cant be right)
if u have the time, why not calculate this properly using the onsite guide?

the 60A 1361 main fuse may be ok,(prob break at about 120A) depending on the total load after calc? how many ccts involved.
secondly, i NEVER change the tails from main fuse to meter, only from meter to C/Unit.
I always cut seals if still there, pull main fuse to do this and re-seal afterwards.

 

[gpz900jim]

No, the total rule of thumb I got to was 71a, it was 177 x 0.4 = 70.8 sorry if it was not clear. So, the tails from the main fuse, I just get the supplier to do? I suppose that if they need doing, which they do, I could request an upgrade of the main fuse at the same time? So if I cut the seal on the meter and connected my new tails from the cu to the meter and requested an upgrade of the tails from the main fuse to the meter, that would be ok generally ? and they would reseal the meter when they do their bit?

 

[ukpablo]

i worked that out mate, 71A divided by 0.4 gives me 177.5A which is what i guessed was ur starting load, therefore 177.5A x 0.4 gives 71A after a rule of thumb diversity

thats why i said multiply by 0.4, ur original post said divide.?
They never like u cutting the seals, (never admit to them either that u do this) so u could request a fuse change and tie it in with ur install, ie get a date off them and arrange to be at property so u can connect into New CU.
In the mean time, either wait or pull fuse and temp terminate into a henley block, and from there take ur new tails to new C unit. Personally, i would do that as they can take up to 6 weeks to even show their faces?

 

[ezzzekiel]

take the full rating of the highest circuit - then take 40% of remainder.........

 

[drew35]

I think the best piece of advise is to not cut the seals until you've spoken to the supplier! And they will almost definitely warn you not to cut the seals, my local supplier wont even allow me to do it in an emergency, I just have to wait for an engineer. Some suppliers take a very dim view of you doing this. Its just as easy to arrange for them to come out and upgrade the tails but fit an isolator at the same time. I always provide the tails, the isolator, and a fuse, just get them to come out and fit it. You can leave it to them to provide everything but they charge the customer three times the retail price for parts, so supply your own!

 

[IQ Electrical]

Hi, I am doing a rewire at the moment. Adding all of the breakers up and dividing by 0.4, gives me a total load of 71a. I will be upgrading the meter tails to 25mm and the main earth to 16mm.. The main fuse is 60a. My questions are;1 how would I go about getting the main fuse uprated? or can I note on the EIC that the main fuse is too small and recommend that the customer gets it uprated ? 2 I need to change the tails from the main fuse up to the meter, and from the meter to the cu. Will the supplier have to come along and fit the meter tails and reseal, or shall I just cut the seal on the meter and just say there wasnt one there at all? There is currently no seal on the main fuse. I know what I should do, but is the real world different ie, what would you do??

Don't forget that as the competent person on site, you should be able to make a better assessment of maximum demand simply by looking at the installations use and users, you are not limited to OSG formulae and rules of thumb.

The good book states: "The use of other methods of determining maximum demand is not precluded where specified by a competent person"

 

[wattsup]

Then when upgrade to 80a or 100a, how come 'the board' get away without part p inspection?

 

[IQ Electrical]

Then when upgrade to 80a or 100a, how come 'the board' get away without part p inspection?

The DNO's work is covered by ESQCR 2002 Regulations, they have no responsibility past the meter, the responsibility then falls on the consumer and his/her appointed contractor.

 

[wattsup]

I love being told not to cut seals, then just cut em, err ok take me to court

 

[gpz900jim]

"I always cut seals if still there, pull main fuse to do this and re-seal afterwards."
The above bit from UKPABLO interests me, how would one re seal again? I didnt think the seals would be obtainable ?

 

[ukpablo]

u can buy them on ebay, look under meter seals.

look, i never work with live tails, i always pull fuse and re-seal afterwards so the customer cannot do the same after i have left, ie leave it as safe as i found it!
if the DNO ever have a prob with this then they can take me to court, my life is more important to me IMO.

 

[rocker]

Cut the seals every time, sod the DNO, no court would prosecute you anyway. Reseal it with the ones off ebay if you wish (you won't have the special embossed print they put in it, we don't reseal to trick the DNO, it's a safety issue) or just use a small cable tie.