Hello All,
Iv been asked to pick up the remedials on someone else's EICR that was done last year on a school for Deaf Children. One of the items listed on the report is the conductors leading to the sub mains from the main panel are undersized. I popped the cover off to have a look and sure enough 4 out of 5 submains have a 16mm XLPE SWA (3 Phase) on a 100 amp MCCB, ok so initially I'm thinking this may need looking into.
But after looking at the sub mains, and there actual loading from the final circuit charts, it would be suffice to say that 2 out of the 4 submains wouldn't be able to even get close, and the other 2, once diversity was applied, would never be able to achieve a loading to surpass there capacity either. I haven't done the exact calc's yet and would like to quote for my time to do an accurate assessment of the loading alongside some of the more straight forward parts which im going back for anyway, but it looks like this would have been why they were installed as such 15 years ago.
The reason I am trying to find this out is the MCCBs are discontinued (willrose don't have any in stock either, Hager HD149 I would need the HD147 or possibly the HD149U rated to 80 amps instead of 100) and the last resort would be to rip the panel out and put a new one in with the correct amperage switches.
Now I'm all for doing what's necessary to be safe, bugger the cost, but surely this should have good reason for having being installed this way originally and as such if I can prove it to be fit for use then I shall do, they are a good client and I don't want to milk them unnecessarily. Should these calculations fall under the CCC would this be justifiable for me to omit changing anything and negate the C2 that was coded for it?
Thoughts and opinions welcome.
Iv been asked to pick up the remedials on someone else's EICR that was done last year on a school for Deaf Children. One of the items listed on the report is the conductors leading to the sub mains from the main panel are undersized. I popped the cover off to have a look and sure enough 4 out of 5 submains have a 16mm XLPE SWA (3 Phase) on a 100 amp MCCB, ok so initially I'm thinking this may need looking into.
But after looking at the sub mains, and there actual loading from the final circuit charts, it would be suffice to say that 2 out of the 4 submains wouldn't be able to even get close, and the other 2, once diversity was applied, would never be able to achieve a loading to surpass there capacity either. I haven't done the exact calc's yet and would like to quote for my time to do an accurate assessment of the loading alongside some of the more straight forward parts which im going back for anyway, but it looks like this would have been why they were installed as such 15 years ago.
The reason I am trying to find this out is the MCCBs are discontinued (willrose don't have any in stock either, Hager HD149 I would need the HD147 or possibly the HD149U rated to 80 amps instead of 100) and the last resort would be to rip the panel out and put a new one in with the correct amperage switches.
Now I'm all for doing what's necessary to be safe, bugger the cost, but surely this should have good reason for having being installed this way originally and as such if I can prove it to be fit for use then I shall do, they are a good client and I don't want to milk them unnecessarily. Should these calculations fall under the CCC would this be justifiable for me to omit changing anything and negate the C2 that was coded for it?
Thoughts and opinions welcome.
