switchgear for lift

[russells]

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

 

[Engineer54]

Yes, i can fully appreciate your dilemma here, the problem with all these LA planners and LABC bods, is that most are all failed private sector engineers...lol!! They have no idea of how things work in the real world, just have a set of rules to guide them.

The thing is, that when these regulations are made, like the separate supply they talk about, it actually means a ''separate'' supply source, it doesn't mean a second supply being taken from exactly the same source as the prime supply point. That second supply source would have been covered, ....if the home had a permanent stand-by generator linked into the system. Which it hasn't, and will add even more variation costs to your project if the work is done correctly.....

All these LABC guy's seem to be doing, is getting over a problem, that they to a point, created for themselves and your company. There solution for this evacuation lift, is a calve-up of the regulations, and is a pointless waste of money/cost. It will in all honesty achieve little to nothing as far as being considered as an essential supply means. The most secure route for a lift supply, is within the lift shaft itself. Very little chance of mechanical or fire damage will be seen when the supply cable is installed using this preferred route....

 

[Engineer54]

Russell,

None of what i've stated is going to help you much in your present dilemma. So if you post photo's of your main distribution board (Open and closed) we may be able to advice you on what you need to fulfill this daft instruction by the LABC...

 

[Specialist]

Yes, i can fully appreciate your dilemma here, the problem with all these LA planners and LABC bods, is that most are all failed private sector engineers...lol!! They have no idea of how things work in the real world, just have a set of rules to guide them.

The thing is, that when these regulations are made, like the separate supply they talk about, it actually means a ''separate'' supply source, it doesn't mean a second supply being taken from exactly the same source as the prime supply point. That second supply source would have been covered, ....if the home had a permanent stand-by generator linked into the system. Which it hasn't, and will add even more variation costs to your project if the work is done correctly.....

All these LABC guy's seem to be doing, is getting over a problem, that they to a point, created for themselves and your company. There solution for this evacuation lift, is a calve-up of the regulations, and is a pointless waste of money/cost. It will in all honesty achieve little to nothing as far as being considered as an essential supply means. The most secure route for a lift supply, is within the lift shaft itself. Very little chance of mechanical or fire damage will be seen when the supply cable is installed using this preferred route....

:clap::clap::clap:

 

[Engineer54]

engineer 54
Thanks for your input.
there is detailed fire evacuation procedure for the building. in fact if the fire is in the existing part of this home the extension is not to be evacuated immediately, there is a 2hr barrier, therefore if there was a fire at the main dis board which wiped out power to this lift, there is a three hour integrity from this fusebopard to the extension were the lift would be used.

Not sure if i'm reading this part of your post correctly or not?? But if a fire started at this Main Distribution Board, (MDB) Then having both supplies to this evacuation lift originating from this same MDB, you would lose both supplies right there!! Which is basically why when they call for a separate supply source, it will mean from ''different'' supply sources.... ie ...2 DNO supplies, DNO supply and Generator, DNO supply and battery UPS, etc. To be perfectly honest Iv'e never seen two supplies for what is going to be an essential service supply being taken from the same power source, in the same panel/board. As i say it's a pointless exercise..

There would be little to no chance of the lift being used during this 3 hour integrity. Or are you just saying, there is a 3 hour fire barrier between the two parts of the building enabling residents to stay relatively safe congregated in the new ground floor extension?

 

[russells]

Engineer 54

yes you are spot on with your analysis that if the fire was in the main DB we would wipe out supply to lift, As I have stated though there exists three hours fire integrity from the DB zone and to the extension were the lift is, so risk assessessed as not over problematic.

You have to take the extension almost in isolation to understand the logic of two supplies from same DB, It is FIRE in any part of the extension itself that the secondary supply is deemed nessessary. If fire started in the extension, the main house would not be evacuated immediately (2 hrs integrity) but the extension would be, and this would be done by way of using lift.

Hope that makes some sense

Russell

 

[Knobhead]

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]

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]

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]

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]

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]

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!

 

[spark 68]

other people on the board will confirm I have a nasty and suspicious mind

It is working with electricity that does that to you Tony! LoL

 

[Specialist]

It is working with electricity that does that to you Tony! LoL

Is that why most good Sparks are Loco ?