Unobtrusive Isolators close to Ovens but needing very long cable runs, are such runs OK.

[MikeSharp01]

The 'interior designer' has persuaded me to locate the isolators for the ovens on the kitchen island so they do not break up the aesthetic of the oven wall. These would be 1.4m from the Ovens across the gangway from the wall with the ovens. Each oven has a max draw of 3600W so 7.2kW with both on full power. Each of the two ovens will have there own 32A isolator in the Consumer Unit (CU), To achieve the run it ends up as a lot of 6mm cable: CU - Island (12m) & Island - Oven (15m) I am going to have 27m run (Voltage drop 3.5V approx), none in insulation but in duct and trunking. [I would need only 5m of 6mm cable if the switches were local to the ovens] So for these two ovens I will need just over 50m of cable which in itself is not a problem but I thought I would get a sanity check here to be sure I am not breaking any rules doing this - it looks OK to me regs wise.

 

Any thoughts - should I push back on the interior designer?

[Nickfromwales]

1 hour ago, MikeSharp01 said:

The 'interior designer' has persuaded me to locate the isolators for the ovens on the kitchen island so they do not break up the aesthetic of the oven wall. These would be 1.4m from the Ovens across the gangway from the wall with the ovens. Each oven has a max draw of 3600W so 7.2kW with both on full power. Each of the two ovens will have there own 32A isolator in the Consumer Unit (CU), To achieve the run it ends up as a lot of 6mm cable: CU - Island (12m) & Island - Oven (15m) I am going to have 27m run (Voltage drop 3.5V approx), none in insulation but in duct and trunking. [I would need only 5m of 6mm cable if the switches were local to the ovens] So for these two ovens I will need just over 50m of cable which in itself is not a problem but I thought I would get a sanity check here to be sure I am not breaking any rules doing this - it looks OK to me regs wise.

 

Any thoughts - should I push back on the interior designer?

What appliances are in the island? Hob I assume?

 

Your designer is spot on, in getting rid of the wall-warts, I always hide these under an adjacent cupboard / unit, Fugly on a good day imho. However, where you need to push back is, the location; have the hob isolator under the island / hob, and the oven isolators in the adjacent units.

[MikeSharp01]

6 hours ago, Nickfromwales said:

hide these under an adjacent cupboard / unit

I could put them in the cupboard below the ovens - the one above would be too high up, would that work? The hob is on the island along with the kitchen ring.

[G and J]

2 hours ago, MikeSharp01 said:

I could put them in the cupboard below the ovens - the one above would be too high up, would that work? The hob is on the island along with the kitchen ring.

Ours are (and/or will be) hidden away in nearby cupboards.  You need access every Julember so why worry about convenient access?

[joth]

It's best to check with whoever will be completing the EIC as appropriate location of isolators is in the regs and quite subjective. Ours insisted on putting them in the very nearest cupboard, which has resulted in a few getting knocked by large items being shoved into said cupboard 

 

Recently I've seen on other projects that electricians seem much less concerned these days, either putting all isolators together next to the CU, perhaps using minigrid switches, or even omitting isolators completely (e.g. for outside blinds). 

If they're happy signing the EIC then fair game. Pretty sure they had more conventional isolator for anything over 13A. 

Edited yesterday at 07:40 by joth

[Nickfromwales]

13 hours ago, joth said:

It's best to check with whoever will be completing the EIC as appropriate location of isolators is in the regs and quite subjective. 

Location of isolators is wide open, and only stubborn electricians would try to polish their sheriffs badge over this tbh. These are there ONLY for localised disconnection, and not for safety etc. Sounds like either a lack of education or dick-swinging went on there.

 

If a sparky told me these were going next to the CU, he'd be going...................on the next bus.

 

16 hours ago, MikeSharp01 said:

I could put them in the cupboard below the ovens - the one above would be too high up, would that work? The hob is on the island along with the kitchen ring.

As above, in units / cupboards immediately adjacent is my go-to solution; so put the hob one in the island. Ask your spark to connect the hob with some HO5 flex and leave enough length to completely remove the hob and set it aside on the island, upside down, for future-proofing.

 

13 hours ago, joth said:

Ours insisted on putting them in the very nearest cupboard, which has resulted in a few getting knocked by large items being shoved into said cupboard 

So, brain-dead then. Off to the side and up very high is the order of the day.

 

The lack of GAF or joined-up thinking with trades still astounds me. That's what keeps me in a job, so, long live the muppets......

[joth]

1 hour ago, Nickfromwales said:

 

If a sparky told me these were going next to the CU, he'd be going...................on the next bus.

In the real world these decisions are really a dialogue, not a mandate. But can be an asymmetric dialogue if the customer isn't informed of the alternatives.

Either way point is to start that dialogue early rather than push it into brinkmanship. Many self builders are not in the position to be able to fire their electrician on a whim over the position of one isolator switch, so better to have the conversation at first fix rather than after the walls and floors are sealed 

 

 

[MikeSharp01]

5 hours ago, joth said:

In the real world these decisions are really a dialogue, not a mandate. But can be an asymmetric dialogue if the customer isn't informed of the alternatives.

Either way point is to start that dialogue early rather than push it into brinkmanship.

Dialogue is always a good approach and one thing this place has taught me is that there are often ideas out there that have not hit your consciousness and this thread is an example. It has saved me about £200 in 6mm cable and a lot of working pulling cables through ducts and along trays - so its a win for me. I do need to build a bit of infrastructure to mount the switches but otherwise its a winner. Thanks all.

 

[Spinny]

Here are a couple of pics showing where we got to with our sparky. Isolation switches in the back of a cupboard for everything on the hob run. (Our sink is going on the island, hob against the wall).

I guess your cable length issue is because you have no direct conduit/trunking between wall run and island. Fortunately we put some in under the floor and it has proven very useful.

 

We are going to put a 3 gang light switch on our island end panel for under wall cabinet wall lights, under worktop LED strip, and shelving LED strip - so cable run happily goes through the hob to island conduit. (As does a water pipe in a separate conduit)

 

(One day in the far off future I suppose kitchen companies might provide designed in electrical box locations, rather than vaguely saying 'one of these cupboards'.)

[Nickfromwales]

8 hours ago, joth said:

In the real world these decisions are really a dialogue, not a mandate. But can be an asymmetric dialogue if the customer isn't informed of the alternatives.

Either way point is to start that dialogue early rather than push it into brinkmanship. Many self builders are not in the position to be able to fire their electrician on a whim over the position of one isolator switch, so better to have the conversation at first fix rather than after the walls and floors are sealed 

 

 

Yup. I usually discuss the fundamentals before the construction phase, eg plant rooms / location of CU / 1ph or 3ph etc and do a basic list of circuits + equipment for getting the connection criteria prepped for the DNO application. 
 

Then, once the sub and super structure are complete we have the next chats for the finer details; by that stage I usually have some provisional design freezes in place for kitchens / bathrooms etc and make suggestions as to ‘what goes where’.
 

Much more sensible to do that once there’s a home to walk about in, and stuff almost always changes when it’s not on a screen anymore.

 

Good trades are hard to find, but they are out there, they just always need booking in 3 months in advance!