Diversity and the resilience of circuit protection.

Evening all.

I thought it was time to show my cards in support of Alan.

I did the period inspection and test on this installation. It is a large house belonging to a friend of mine. All of these large kitchen appliances are on a single radial. That radial is wired in 6/2.5 T&E grouped with other T&E, some of it enclosed and with some parts in insulation. The cable is protected by a BS 3871 Type 2 45A circuit breaker. That cable as installed is not protected against overload so does not meet Regulation 433.1.1. My observation for this was a C2. My report, my signature my liability. You may code the non-compliance differently to me but that is your report, your signature your liability.

I do know what diversity is and I do know it is not an exact science. The connected load is 21.kW which is 91.7A. The previous occupant was a woman living alone. The new occupant is my friend and could very well host a large diner party cooked by professional caterers hired in for the night. A lot of the connected load may be in use at the same time. So in these circumstances how would you design this installation and circuits? Would you put all that kitchen plant on a single 6/2.5 radial?

The installation is about 40 years old, a single 12 way old Wylex board, no RCD protection with many alterations and additions  by muppets. Many non-compliances, bunched circuits including 2 No. Air Con compressors,  low insulation resistance, unearthed Class 1 fittings etc etc. 

The supply was a 80A PME supply now upgraded to 100A by WPD. The supply supplies a large double garage and work shop, where the main switch is and a 70mm SWA to the house. The supply at the moment also supplies a new building with a further 95mm SWA. This building has not been used yet. A flat  over 2 large double garages. This building is going to be extended I have agreed with WPD for a further 100A supply to the new building but this will be TT as directed by WPD.

Alan is working his socks off fault finding, cable tracing and locating unknown circuits (as usual the consumer unit was not marked up) and clearing up the general mass of carp installed by the muppets over the years. I can vouch that he is very well qualified electrician, experienced and diligent person. If he was not he would not be doing this job without my endorsement and approval. Alan will be jointing the 95mm underground cable to extend it to the new external GRP cabinet for the new incoming supply, installing an earth mat in conductive concrete for the TT earth. Beyond the capability of the average electrician nowadays!

PS just looked at my NAPIT Code Breaker book that also say C2 for the absence of overload  protection for a cable.

Evening all.

I thought it was time to show my cards in support of Alan.

I did the period inspection and test on this installation. It is a large house belonging to a friend of mine. All of these large kitchen appliances are on a single radial. That radial is wired in 6/2.5 T&E grouped with other T&E, some of it enclosed and with some parts in insulation. The cable is protected by a BS 3871 Type 2 45A circuit breaker. That cable as installed is not protected against overload so does not meet Regulation 433.1.1. My observation for this was a C2. My report, my signature my liability. You may code the non-compliance differently to me but that is your report, your signature your liability.

I do know what diversity is and I do know it is not an exact science. The connected load is 21.kW which is 91.7A. The previous occupant was a woman living alone. The new occupant is my friend and could very well host a large diner party cooked by professional caterers hired in for the night. A lot of the connected load may be in use at the same time. So in these circumstances how would you design this installation and circuits? Would you put all that kitchen plant on a single 6/2.5 radial?

The installation is about 40 years old, a single 12 way old Wylex board, no RCD protection with many alterations and additions  by muppets. Many non-compliances, bunched circuits including 2 No. Air Con compressors,  low insulation resistance, unearthed Class 1 fittings etc etc. 

The supply was a 80A PME supply now upgraded to 100A by WPD. The supply supplies a large double garage and work shop, where the main switch is and a 70mm SWA to the house. The supply at the moment also supplies a new building with a further 95mm SWA. This building has not been used yet. A flat  over 2 large double garages. This building is going to be extended I have agreed with WPD for a further 100A supply to the new building but this will be TT as directed by WPD.

Alan is working his socks off fault finding, cable tracing and locating unknown circuits (as usual the consumer unit was not marked up) and clearing up the general mass of carp installed by the muppets over the years. I can vouch that he is very well qualified electrician, experienced and diligent person. If he was not he would not be doing this job without my endorsement and approval. Alan will be jointing the 95mm underground cable to extend it to the new external GRP cabinet for the new incoming supply, installing an earth mat in conductive concrete for the TT earth. Beyond the capability of the average electrician nowadays!

PS just looked at my NAPIT Code Breaker book that also say C2 for the absence of overload  protection for a cable.