mcb for a lift

[kfelec]

alright all

im going to a job in the morning havent seen or been there yet but i have to put a new mcb in the ccu for thr lift im not sure yet if its rcd protected?

with it being a feed for the lift should it have a rcd, rcbo protection or just an mcb the reason i ask is because in case it trips and people are stuck inside the lift

any views thanks

 

[PrinceofDarkness]

You'd be better off posting tomorrow after your visit, rather than inviting speculation from others here on the unknown.

If you don't know about elevator supplies, perhaps you should sub-contract the job........


Lucia.

 

[kfelec]

true thanks anyway

 

[333rocky333]

I would think a Hrc switchfuse may be more suitable.

 

[ColJack]

aren't we getting into auto-resetting breakers and such for lifts?

 

[ricicle]

aren't we getting into auto-resetting breakers and such for lifts?

No. Usually dedicated supplies from the origin of the installation.

 

[ban-all-sheds]

Does one not need any special competencies to work on lifts?

I can see me taking the stairs a lot more often if the alternative is getting into something which has been fiddled with by someone so ignorant of the task that he has to ask how to do it on a DIY forum....

 

[nozspark]

To actuall work on a lift or in the lift shaft you do need to be a lift engineer, but the supplies can be installed by sparks..

Remember no cabling other than that for the lift is allowed to be in the lift shaft.

If it was me I'd be installing a HRC switch fuse, normally in a locked switch room!

 

[PrinceofDarkness]

Lift motors are never connected to an RCD circuit in this country - even in small private buildings such as the block where Stirling Moss lives........

They are always 3-phase (with the exception of dumb waiters and very small hotels with facilities for the disabled) and protected by HRC fuses.

Lift motors are designed to have a (more than necessary) high resistance winding in order to be more dependable and less prone to burn-out. This makes them slower in operation compared to a normal industrial work horse of the same power.

RCD? Forget it!

Lucia.

 

[bhm1712]

Lift motors are never connected to an RCD circuit in this country - even in small private buildings such as the block where Stirling Moss lives........

They are always 3-phase (with the exception of dumb waiters and very small hotels with facilities for the disabled) and protected by HRC fuses.

Some lift motors are DC and so not 3 phase.
Modern lift control gear using inverter drives have built in earth fault detection, so if the motor does develop an earth fault it will stop only the motor, not the entire supply to the lift control gear and ancilliary stuff. In the situation of an earth fault, the brakes can then be manually released to allow the car to travel to a floor in order to get people out.

 

[RF Lighting]

I don't think I've ever done a lift supply fed from anything other than HRC fuses or an MCCB.

Why would anyone even consider RCD protecting a lift supply

 

[Steve]

Why would anyone even consider RCD protecting a lift supply

15 people stood inside a big metal box with big metal doors that goes up and down a metal track suspended by big metal cables powered by a big metal 400v motor.

Point taken though, the risk of a nuisance trip, and trapping people endangering lifes, far exceeds the risk of shock here.

 

[kfelec]

thanks for the replies i just wanted a little bit of info before i got to the job

 

[RF Lighting]

15 people stood inside a big metal box with big metal doors that goes up and down a metal track powered by a big metal 400v motor.

Never heard of a faraday cage then?

 

[ban-all-sheds]

Why would anyone even consider RCD protecting a lift supply

15 people stood inside a big metal box with big metal doors that goes up and down a metal track suspended by big metal cables

Sort of a Faraday cage then...