MCB characteristic at high voltage

This will fail.

The MCB is designed to work at designed voltage level.If higher voltage is applied it will fail due to insulation.

Every electrical has itsoperating voltage level.Why would u like to have this MCB operating at high voltage when there are specific breakers for those applications. As informed there will be a flash over .

Refer cherecteristics from supplier catlog.

Due to the ignorance shown by your question, I am sorry I have to point out to you that it is not wise to play with this equipment. Not only your safety is at stake but their are always people around you and / or in the building.

What would you feel like if your building burns down due to your handy work and 3 fireman died trying to save you out of this burning building?

Let it go and contract a proper electrician with qualifications.

I think you are all missing the point of the enquiry.

The enquirer is asking if he can use MCBs marked with a higher voltage rating than the ones in service.

The answer is 'YES'. The voltage marked indicates the voltage up to which the device can be used,.i.e. a figure of merit. The voltage rating has no effect on the current characteristics as the device works on current only.One caveat, AC only.Dont mix AC and DC breakers.

In general some of the respondents are adopting an unfortunate attitude of 'if you have to ask the question then you do not know enough to safely employ the answer'. We will be even more likely to blow ourselves up if you have discouraged us from asking questions.

Summary:

Questioners should use

• Short sentences
• Seperate the Question from other( his own) advice/comment.

He could have asked like this:

" My factory is wired 50Hz 3phase+neutral =415/240V

All my MCB's have markings of" Max 480V"

I have some Spare MCB'S with markings "Max.800VAC"

Can I use the latter for some new machine at my factory?I shall make sure that load Amperes will be within what is marked on MCB label.

"In general some of the respondents are adopting an unfortunate attitude of 'if you have to ask the question then you do not know enough to safely employ the answer'. We will be even more likely to blow ourselves up if you have discouraged us from asking questions."

Since when is advising somebody to use a qualified electrician instead of employing a new found knowledge with possible dire consequences a discouragement for asking questions?

Your world is upside down my friend. You ask, you get answers. It is up to the reader to act upon this info or not. If he or she was afraid to ask but did not know and STILL went ahead and blew themselves up, you would blame us for having discouraged them!

You sound like you are a member of the new politically correct brigade, and just in case you hadn't noticed, not many here like that brigade very much.

It's really all a moot point. I know of no MCB's (Miniature Circuit Breakers) that are rated for any voltage higher than 690V and those are rare. Most MCB ratings stop at 415Y230V anyway.