Electrical Supplies To Lifts

You need to know if it an evacuation lift, or, a general use lift that will fail if the supply cuts out.

(from memory, check it is still right) If an evacuation lift, it gets complicated in that it must have two independant supplies - the main, usual supply, then one for back up if the main supply fails. I understand that the second supply could be batteries, or a generator, or, if from the 'street/public supply' should be from a separate transformer, along with its own separate secondary supply DB (which can contain other 'life saving ancillaries' supplies.)

As for power requirement, the ones I've done are quite small, typically 32A 3 phase and neutral, SWA from the DB to where the motors sit, then a suitable isolator, from where the Lift Installers take their feed.

I havce absolutely no idea as to the actual final specs as of yet. Although not being responsible for the project other than for a supply I would not be a fan of having an evacuation facility via lift. Am thinking something like the weight of say, 4 people at a time but again, I have no idea as to what quotations or specifications exist at this juncture. Am thinking a Type C or D OPD due to intermittantant motor loads?

whjohnson said:

Am thinking something like the weight of say, 4 people at a time but again, I have no idea as to what quotations or specifications exist at this juncture. Am thinking a Type C or D OPD due to intermittantant motor loads?

Thats sounds quite small, so a 32 amp 3PN supply should cover it, though, of course, check the specs before buying any cable. Calculate the cable to allow for a D type circuit breaker, but a C type has been usual for the small shop lifts I've fitted in the past.

Oh, I also remember one Lift Manufacturer wanted two supplies, one for the lift workings, and another just for the lighting.

whjohnson said:

Am thinking something like the weight of say, 4 people at a time but again, I have no idea as to what quotations or specifications exist at this juncture. Am thinking a Type C or D OPD due to intermittantant motor loads?

Thats sounds quite small, so a 32 amp 3PN supply should cover it, though, of course, check the specs before buying any cable. Calculate the cable to allow for a D type circuit breaker, but a C type has been usual for the small shop lifts I've fitted in the past.

Oh, I also remember one Lift Manufacturer wanted two supplies, one for the lift workings, and another just for the lighting.

Thanks for your input.

I think the principle driver for installing a lift is to provide disabled access, so maybe 2 wheelchairs with accompanying adults, so 4 people max. It is also possible that the lift may be used to transport light goods such as stock for the upstiars public bar, so small packs of mixers etc.

It is all quite vague at present with nothing firmed up.

whjohnson said:

I think the principle driver for installing a lift is to provide disabled access

whjohnson said:

There are 4 staircases leaving the main hall for that purpose and are wholly adequate, so I don't foresee any need for any safety/building evacuation measures to include the use of a electric lift.

If you take people with restricted mobility up in a lift, you have to bring them back down again.

As BS 81-76:2025 points out, at one time, lifts were not to be used in the event of a fire, but policy has changed.

That said, what happens after the isolator is not your problem, so by all means quote for the provision of a new supply and leave it at that.

Chris Pearson said:

There are 4 staircases leaving the main hall

Just check that the main stair cases are the actual fire exits.

Often those main staircases can be open fancy glass based 'atrium' accesses.

My former work had that. The fire marshal’s main job during fire drills was to stop folks using the main glass doors and stair well because they were just 'pretty' and weren't fire rated! [The marshals had other equally important task as well ]