Size of Micro breaker

[Ray Tay]

Thinking of having a micro circuit breaker at the consumer unit for each heavy kitchen appliance. The cable will be 2.5mm from the CU to the appliance. Fridge/freezers, oven, etc tend to be below 13A these days. Some of the appliances come with moulded 13A plugs.

1. Having a fuse behind an appliance in a unit in an inaccessible place appears rather dumb. The plug can be removed and the flex wired into an outlet box. The installation will certainly conform to the 17th. But will the makers honour any guarantee if the appliance has the plug removed?

2. Having the micro breaker at an appropriate current rating for the appliance and its flex, fopr e.g., say 10A?

 

[bernardgreen]

The plug can be removed and the flex wired into an outlet box.

a) how will you ensure isolation when a service man comes to repair the appliance, they will have to un wire it instead of simply un plugging item.

b) how will you isolated it ( Both Live and Neutral ) if it develops an earth fault.

there are other considerations as well.

 

[ban-all-sheds]

Thinking of having a micro circuit breaker at the consumer unit for each heavy kitchen appliance.

Why?

What benefits are there of that at all, let alone ones which justify the expense and effort to install all those cables, a larger CU etc?

The cable will be 2.5mm from the CU to the appliance.

Why?

What distances and/or installation methods are involved that require such a large size?

Fridge/freezers, oven, etc tend to be below 13A these days. Some of the appliances come with moulded 13A plugs.

Indeed.

So why do you think you need such large cables?

1. Having a fuse behind an appliance in a unit in an inaccessible place appears rather dumb.

Don't do it then.

Or, alternatively, put forward some sound engineering-based reasons of why a fuse might blow and the appliance to not need pulling out for investigation or repair.

The plug can be removed and the flex wired into an outlet box. The installation will certainly conform to the 17th.

Ah - so you'll be getting an electrician to do all this for you.

At least you will provide a source of entertainment for him and his mates when he tells them about his mad customer.

But will the makers honour any guarantee if the appliance has the plug removed?

They should.

2. Having the micro breaker at an appropriate current rating for the appliance and its flex, fopr e.g., say 10A?

Why 10A? Are you planning to replace the appliance flexes with really, really small ones?

 

[Taylortwocities]

2. Having the micro breaker at an appropriate current rating for the appliance and its flex, fopr e.g., say 10A?

Oh, not this again.

Most people achieve what you are thinking of with something like this

LOTS of other makes available….

 

[Iggifer]

The thing I really like about the nexus grid is the pop off rocker cover. I know other people do engraved switches, but I like the flexibility

 

[winston1]

Having a fuse behind an appliance in a unit in an inaccessible place appears rather dumb.

Really. Would you also say having a fuse inside an appliance that you can only get at by taking off the covers is dumb?

 

[flameport]

Having a fuse behind an appliance in a unit in an inaccessible place appears rather dumb.

Easily resolved by rewiring your entire house with 16A radials, installing schuko sockets in all rooms and fitting new plugs on every appliance you own. Or purchase all new appliances from Europe, and they will be supplied with the correct plug.

The plug can be removed and the flex wired into an outlet box. The installation will certainly conform to the 17th. But will the makers honour any guarantee if the appliance has the plug removed?

The guarantee won't be affected, but if repairs are required they won't be happening until the appliance flex is disconnected. Visiting repair persons will not disconnect flexes from outlet boxes or similar, they expect a plug and socket arrangement to ensure proper isolation.

2. Having the micro breaker at an appropriate current rating for the appliance and its flex, fopr e.g., say 10A?

Not needed since they will all be 16A.

 

[Ray Tay]

winston1, Really. Would you also say having a fuse inside an appliance that you can only get at by taking off the covers is dumb?
There is a massive difference to removing a plate to dragging out a heavy appliance. If an appliance can be repaired by not removing from the unit, if there is a fault and the breaker trips then it is a matter of repair, test and switch back on the breaker. No having to drag out the appliance to change a fuse at the back.

flameport, I only want radials on the dedicated heavy appliances, nor do I want Continental plugs. The micro breakers will be double pole which gives 100% isolation. It saves having isolators over worktops.

Taylortwocitioes, thanks for the Nexus grid switches. They are neat in a two floor place. In this case it is for a flat where the CU will be easily accessible at face height just in the hall outside the kitchen.

I have come down on a double pole micro breaker to serve only one heavy kitchen appliance. The micro breaker will be sized to the appliance. e.g., 10A. If the appliance, says a fridge, and comes with a 13A fused plug, that will be left in and the micro breaker sized to suit, say 10A, then the 13A fuse is overridden. Then the oven maybe 16A of whatever the oven states. I have seen most ovens come without plugs, unless one of those very small ovens that plugs into a ring.

Then cable, flex and appliance are all protected to a higher level.

 

[winston1]

winston1, Really. Would you also say having a fuse inside an appliance that you can only get at by taking off the covers is dumb?
There is a massive difference to removing a plate to dragging out a heavy appliance. If an appliance can be repaired by not removing from the unit, if there is a fault and the breaker trips then it is a matter of repair, test and switch back on the breaker. No having to drag out the appliance to change a fuse at the back.

With most heavy appliances such as washing machines, dryers etc the plate you need to remove is on the back or possibly the top. How dumb of the manufacturers to make an appliance that you need to drag out to remove a plate for service!

 

[flameport]

the micro breaker sized to suit, say 10A, then the 13A fuse is overridden.

No it isn't.

 

[Echo the husky]

How dumb of the manufacturers to make an appliance that you need to drag out to remove a plate for service!

With many Miele washing machines, a lot of the servicing/repairs can be carried out from the front of the machine without pulling it out from under the worktop.

My previous job was installing and repairing domestic appliances. Fuses blowing was really quite a rare occurrence. Rare enough that major wiring alterations really isn't necessary, or even recommended.

 

[Ray Tay]

Echo the husky, My previous job was installing and repairing domestic appliances. Fuses blowing was really quite a rare occurrence. Rare enough that major wiring alterations really isn't necessary, or even recommended.

My old high level built-in oven had most points fixed from the front. What do you mean?......'Rare enough that major wiring alterations really isn't necessary, or even recommended'

flameport, a 10A breaker on the same line as a 13A fuse will break first. This is rather fundamental stuff. But your mind does wander a little, rambling on about Continental systems and the likes.

 

[magicmushroom666]

Unfortunately its not that simple with fuses and breakers, depending on the characteristics of both the fuse and breaker, and the size and duration of the over current situation, either unit could trip first.

 

[Taylortwocities]

a 10A breaker on the same line as a 13A fuse will break first. This is rather fundamental stuff

If we are talking fundementals, something in my "basic principles" folder says that it is fundamentally bad practice to have a lower current CPD upstream of a larger one!

 

[bernardgreen]

Echo the husky, My previous job was installing and repairing domestic appliances. Fuses blowing was really quite a rare occurrence. Rare enough that major wiring alterations really isn't necessary, or even recommended.

Ray Tay, please learn how to quote in the correct way

{quote="Echo the husky"}, My previous job was installing and repairing domestic appliances. Fuses blowing was really quite a rare occurrence. Rare enough that major wiring alterations really isn't necessary, or even recommended.{/QUOTE}

Replace the curly brackets { } with square ones [ ]