Hi all, this is my first post on this site so please be gentle. My background is electronics and am not a qualified sparks so I understand some of the issues and regs but clearly not all.
I have a problem and a potential solution but I would like to run it past a professional before asking my part P qualified relative to come over and sort it out.
In our kitchen we have a single electric oven, a combination microwave oven and an induction hob. The single oven and hob are hardwired to an adjacent 45a switched DP cabled in 6mm back to 30a fuse in CU. So far so good. The combination microwave is fed separately from the kitchen ring main via an FCU. The adjacent FCU outlet is cabled in 2.5mm to a 25A flex outlet plate behind the oven and the oven flex is hardwired into this.
Now comes the problem. The existing oven only required a 13a supply and although I believe the guidance suggests no more than 2.2kw on a final ring it was fine for 12 years without any problem.
The oven has now died and the cost of parts makes it uneconomical to repair so I am looking for a replacement. The siemens unit I am looking at with the larger grill and higher output microwave according to spec is rated at 3.6kW, 15A so it cannot be fed through the existing 13A FCU.
I imagine the optimum solution here is to provide a new radial supply from the CU fused at 16A to an adjacent cooker DP switch which will connect to the existing 25A flex outlet plate ( new oven is fitted with captive flex). The immediate problem with this is that cabling to the CU will be awkward and messy and within the next year our bungalow will be extended and altered so cables will have to be moved/extended/replaced as necessary at that time.
Putting a new dedicated feed to the combi oven would ideally be done as part of the alterations when the CU will be upgraded and new rings added as part of the work so I am looking for a safe, reasonable, short term arrangement that will allow a slightly higher power oven to be connected without a new dedicated cct. This is where your advice would be very helpful.
It seems to me that the max 15A that the new unit will draw is well within the capacity of the existing kitchen final ring and despite the max 2Kw recommendation I have heard about, the old oven drawing a max of 13 amps never caused any problems with other appliances on the same cct which has never tripped.
I was thinking that until the kitchen is rewired as part of the alterations, the current FCU, fed from the ring, which fed the old oven could be swapped for a 45A cooker DP (fed from the ring) which would be cabled to a 16A MCB in a single housing mounted on the wall just above the oven tower and then the output cabled down to the existing 25A flex outlet plate behind the oven housing.
As I see it, the output cable from the cooker switch is effectively just a switched spur which would be protected from overcurrent by the 16A MCB and the same would be true of the oven cabling. I appreciate that there would be a slightly increased chance of tripping the kitchen ring due to the potential extra couple of amps the oven could draw on "full everything" but I don't think it would be an issue. With that in mind, would this arrangement be acceptable or is it a complete NO NO.
Any advice will be very welcome.
I have a problem and a potential solution but I would like to run it past a professional before asking my part P qualified relative to come over and sort it out.
In our kitchen we have a single electric oven, a combination microwave oven and an induction hob. The single oven and hob are hardwired to an adjacent 45a switched DP cabled in 6mm back to 30a fuse in CU. So far so good. The combination microwave is fed separately from the kitchen ring main via an FCU. The adjacent FCU outlet is cabled in 2.5mm to a 25A flex outlet plate behind the oven and the oven flex is hardwired into this.
Now comes the problem. The existing oven only required a 13a supply and although I believe the guidance suggests no more than 2.2kw on a final ring it was fine for 12 years without any problem.
The oven has now died and the cost of parts makes it uneconomical to repair so I am looking for a replacement. The siemens unit I am looking at with the larger grill and higher output microwave according to spec is rated at 3.6kW, 15A so it cannot be fed through the existing 13A FCU.
I imagine the optimum solution here is to provide a new radial supply from the CU fused at 16A to an adjacent cooker DP switch which will connect to the existing 25A flex outlet plate ( new oven is fitted with captive flex). The immediate problem with this is that cabling to the CU will be awkward and messy and within the next year our bungalow will be extended and altered so cables will have to be moved/extended/replaced as necessary at that time.
Putting a new dedicated feed to the combi oven would ideally be done as part of the alterations when the CU will be upgraded and new rings added as part of the work so I am looking for a safe, reasonable, short term arrangement that will allow a slightly higher power oven to be connected without a new dedicated cct. This is where your advice would be very helpful.
It seems to me that the max 15A that the new unit will draw is well within the capacity of the existing kitchen final ring and despite the max 2Kw recommendation I have heard about, the old oven drawing a max of 13 amps never caused any problems with other appliances on the same cct which has never tripped.
I was thinking that until the kitchen is rewired as part of the alterations, the current FCU, fed from the ring, which fed the old oven could be swapped for a 45A cooker DP (fed from the ring) which would be cabled to a 16A MCB in a single housing mounted on the wall just above the oven tower and then the output cabled down to the existing 25A flex outlet plate behind the oven housing.
As I see it, the output cable from the cooker switch is effectively just a switched spur which would be protected from overcurrent by the 16A MCB and the same would be true of the oven cabling. I appreciate that there would be a slightly increased chance of tripping the kitchen ring due to the potential extra couple of amps the oven could draw on "full everything" but I don't think it would be an issue. With that in mind, would this arrangement be acceptable or is it a complete NO NO.
Any advice will be very welcome.
