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]

very tricky situation,id speak to the lift manufactures ie otis/kone etc and see what they recommend supply wise in the event of a fire and evacuation as they id imagine would have strict guidelines and power supply needs that their equipment needs in such an event

In normal building fire situations, on inital fire alarm activation, lifts will decend to ground floor, open and then close doors after time delay and then power down and remain there. In this case they want the lift to be operational as a means of evacuation for patients etc...

I maybe would take advice from them, regarding statutory requirements, but little else...

 

[alarm man]

In normal building fire situations, on inital fire alarm activation, lifts will decend to ground floor, open and then close doors after time delay and then power down and remain there. In this case they want the lift to be operational as a means of evacuation for patients etc...

I maybe would take advice from them, regarding statutory requirements, but little else...

id take what they say as gospel really,they
make them and set guidelines how they work,if anything fails in an emergency,the standard reply would be'you did what? oh no we recommend you do this'

 

[spark 68]

It may be that the OP has got to liase with more than one party,
as we don't know whether the lift is controlled by a BMS system.

There are too many blanks to fill in at this point in time, but whatever the OP originally thought that this was a simple question, I agree with E54, this has opened a big can of worms.

I know enough to know that I don't know enough.

 

[Engineer54]

Hmmmm, .... From Experience, i wouldn't take everything they say as gospel!! If you think they will put things in writing for you, then your going to be sorely disappointed. All they will give you, is there power requirement for there installation. they will not be interested in how it gets there, that is, as long as it's not run in there lift shaft!! Anything they put in writing, they will be responsible for, ....believe me they won't do it!! lol!!!

 

[alarm man]

Hmmmm, .... From Experience, i wouldn't take everything they say as gospel!! If you think they will put things in writing for you, then your going to be sorely disappointed. All they will give you, is there power requirement for there installation. they will not be interested in how it gets there, that is, as long as it's not run in there lift shaft!! Anything they put in writing, they will be responsible for, ....believe me they won't do it!! lol!!!

they will,an evacuation lift differs from a passenger lift,hence different regulations and supplies.

 

[Engineer54]

they will,an evacuation lift differs from a passenger lift,hence different regulations and supplies.

They will , ..What?? As i said, i would take note of any regulation they may quote, but that's about it!! I can assure you they won't put anything else in writing, there not even too interested in your problems. I've dealt with all the big international lift companies and there all basically the same!!!

 

[russells]

Ok, A big thanks to all who have posted to this topic.

The situation is that we are a design and build company, our client as already struggled to meet some of the variations to our contract, (the cost is escalating). he is about to cop yet another additional cost, (secondary supply for lift and changeover switching). as a measure of keeping a lid on these costs i am making sure our electrical contractor dosent "sniff gold", to do this i want to be able to converse fluently about what may be required. its early days yet, I will keep this post alive as things develop.

a couple of clear up lines.
1. Yes sorry it is a three phase motor.
2. The back up generator powers up the main Dis board, (the home owners are going into a contract with a company that installs a hook up and supplies a genny at 4 hrs notice if power is off)
3. Lift company have agreed principle of secondary supply.

Russell

 

[benji]

might be worth using FP400 cable instead of usual SWA cable

 

[Engineer54]

a couple of clear up lines.
1. Yes sorry it is a three phase motor.
2. The back up generator powers up the main Dis board, (the home owners are going into a contract with a company that installs a hook up and supplies a genny at 4 hrs notice if power is off)
3. Lift company have agreed principle of secondary supply. Russell

Russell,


From what you describe here, i can see little point or reason for a second/essential supply to this lift, as it's not being derived from a separate source. The fact that there is no permanent stand-by generation facility also leads me to this conclusion. All you will be achieving by supplying an automatic dual supply to this evacuation lift from the same DB/supply, is negating a fault on one of the supplying cables or protective devices. I can't see it being of any use in a fire condition either, as it will probably take more time to destroy one of the supplying cables than it will to have completely evacuated the building, especially when as you say the fabric of the building is almost totally fireproofed

If the generator is being supplied by a company, only as and when needed, then there is no-need for an auto change-over switch on that side of things either, Just a standard manual changeover switch will suffice, along with a means of easy connection to the changeover switch...

EDIT... How many dwelling units is this fire evacuation lift covering, has an evacuation time for residents been considered in the risk assessment of this building, if so what is that time allowance...

 

[russells]

engineer 54

Thanks for your input.

Quite simply, I have been in a meeting with LABC, and fire officer + client.
LABC will not agree to a fire strategy for the layout of the building (yes i know this should of been approved at the early design stage, but commercially the home extension needed x amount of bedrooms to be viable as a buisness, yet plannners restricted the footprint of the building, CQC have strict guidelines on bedroom size and communal room size, thus resulted in a single staircase and a lift. At the meeting LABC have agreed that if the lift is used as part of evacuation then criteria in part B is met,

For said lift to meet requirements a secondary electrical supply as to be installed, that takes a different course through building to lift motor room.
Many questions have been raised here that are not really relevant, 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. The rules change for mass evacuation when old and vunerable people become involve, ( as you can imagine fire does not care if it arrives on a -10 degrees freezing 2 0 clock in the morning, or even in a torrential prolonged downpour, Exposing old people to something like that because you have mass evacuated a building which only as a car park as a muster point.

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