switchgear for lift

russells · Dec 4, 2011

Hopefully this one will be a simple one to answer.

A lift in a premises as been determined as a fire lift (to be used in evacuation under fire conditions)
the lift as to have 2 supplies of power, with basically switchgear (not provided in the lift electrics) that would simoultaneously cange the supply if one of the cables supplying was burnt out.

So this is the situation, we have a mains board in a building with plenty of spare ways in the board, and capacity, we will run two single phase supplies from this board to the lift motor room (by the way the fuseboard cupboard, and the lift motor room have enhanced fire protection) the cables have to go through different routes in the building fabric to get to the motor room (basically have a fire compartmentation drawing of the building and cabling must take different routes in different fire zones) (fire officer happy with this so).

My question is what switchgear do we have in the motoroom, we obviously have two cables from the same fuseboard that will go through a changeover switch, one cable will be master(either one) and one will be slave. the need will be for the power to not be interupted to the lift.

it is possible that we could use a manual type switch, again what would this switch be called, does this exist.

I am not an electrician but a construction manager, this problem is looming in the near future, this isnt in original building spec and will have to cop the cost our electrical contractor is going to wrap me up in smoke and mirrors and try and charge me a fortune so hopefully can gather as much information as possible.

Welcome any questions, and of course answers.

Russell

Knobhead · Dec 6, 2011

Russell, I will give you a scenario. The main board burns out, so there is no supply to the lift by any rout. The lift is as you say separated by barriers from the fire so the lift area is relatively safe.
Now just before the supply is lost a couple of residents get in the lift, how do you get them out?
Believe me it’s not an easy task to do safely. I got stuck in a lift in a 300’ high tower. There was only one person on site trained in manual lift rescue, ME and I was stuck! The repercussions within the company went far and wide.

malcolmsanford · Dec 6, 2011

Most of the lifts we do over here Tony have a dedicated battery pack that in event of a power failure and there is not a generator back up, this pack will allow the car to level to the nearest floor and open the doors, pretty sure that must be virtually standard back in the UK.

There is a rabbit away here somewhere if as Russel say that the HSE have authorized a dual supply from the same source. It is either some sort of mis-communication on their part and the consultant or they seem to have it completely wrong

Knobhead · Dec 6, 2011

The smallest lifts I’ve worked on were 2-ton payload. So OK I’m not 100% on modern passenger lifts.

A single source for two supplies defeats the whole point as far as I can see. This whole set up doesn’t sit easy with me.

Specialist · Dec 6, 2011

Tony said:
The smallest lifts I’ve worked on were 2-ton payload. So OK I’m not 100% on modern passenger lifts.

A single source for two supplies defeats the whole point as far as I can see. This whole set up doesn’t sit easy with me.

With all due respect to Russell, none of it sits easy with me either mate. As I said previously i've been involved with installing supplies for a number of lifts in Old peoples homes & disabled facilities in the past, never once did the back up supply come from the same source as the primary supply. The mind boggles.

needasparks · Dec 6, 2011

This does seem a pointless to have two supplies from the same origin I know someone said FP400 but what about MICC as it would have better machanical protection and run cherry hot.
It could then be run in the lift shaft as its the only supply cable that can, if was damaged by fire so would the people in the lift surely.

Knobhead · Dec 6, 2011

MICC or a bit of wet string with knots in it. If the source fails the lift supply is useless no matter which way it goes.

The whole set up is flawed considering it’s a supposedly approved rescue rout.
I honestly can’t see it passing a fire risk assessment and as such I’m having serious doubts about Russell’s role in this.

Russell, other people on the board will confirm I have a nasty and suspicious mind and don’t hold back if I think something is wrong. I don’t think anyone on here will give you back up to cut costs on this project given the safety issues. You did mention the unacceptable cost of a second independent supply that set the alarm bells ringing for me.

Costs before safety!