I'm having my council house rewired. I have an existing out building with high demand appliances running on 3 phase inverters. It has its own fuse board with a 50a main circuit breakers running to a 50a smaller breakers in the main house fuse box. They now tell me that they that they cannot get a 50a breakers for the house fuse box and proposed to put a 32a instead..is this safe and acceptable?? Sorry for the lack of knowledge I'm no electrician
Help please
- Thread starter damov8
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They insist that 50a are not available for the new fuse box...it used afdd-rcbo...by waylex
Begs a question why an AFDD has been specified for the submain and what are you using that needs so much power?
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Is this an ex-council house that you have now purchased...
Or is it still a council owned property?
If still council owned, are they saying they won't give you the 50A supply rather than they can't give you a 50A supply?
As a general rule a lower rated supply cannot be unsafe..
But it could well be a bit inconvenient due to nuisance tripping if your load exceeds the supply.
(especialy where you could have some significant start-up surges).
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I assume you mean Wylex?
It seems they are only available up to 40A https://www.discount-electrical.co.uk/section.php/111481/1/wylex-afdd-rcbos
How many machines do you use at once? Does it really need more than 40A? That's 9kW?
It's still a council house. The council contractor say they will only fit a 32a as 50a is unavailable for the new consumer unit.
I assume the original electrician took startup into account when he fitted the 50a..
Yes sorry wylex. Thank you for the link..
I use 2x 3 phase machines each has a 3 phase pump attached. So 4x 3phase motors running in total.
I have no idea how much power they use but the original electrician had all the information on the machines so maybe he thought 50a was correct...??
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Sorry I am getting a bit confused by this....? (possibley one to two too many liquid-based evening snacks!!!
)So was this "other" electrician not a council contractor?
Why isn't the original person who assessed your requirements, and has seen your actual installation arrangement still involved?
Maybe if the old supply was via a 50 amp B Curve MCB, Wylex do a 40 amp C Curve module which may be suitable?
I would imagine that if the lathe etc is on an inverter then it has soft start and there will be next to no start up surge.. Can you tell me what make and model of lathe and miller you have as i will be able to help you more then..
john..
john..
Inverters can have quite a surge when powering up, that was my thinking to protect against nuisance tripping.
I have a smart and brown M mk2 lathe with suds pump and a Boxford vm30 milling machine with suds pump each running teco inverters..
Hi there, Nice quailty stuff then!! Anyway, you should have no problems at all running either of these from a MUCH smaller supply than 50A
Any idea what size motors are fitted?? No larger than about 1 or 1.5 hp i would think.. To be honest i would think that a 10A supply with a "C" curve mcb would be more than enough..
Not looking for a VERY nice Erickson boring head to go with your mill are you?? Each gradutaion is just 2 microns!!.. Have a look at this..
https://www.facebook.com/marketplace/item/634234724771689
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