Running a supply for a fire mist system

[opps]

Hi all

I need to run some FP200 to an automist fire dampening system. I have already cut holes in the hallway walls and cut notches in the studs. Where the cable enters the walk-in in cupboard where the boiler and and consumer unit are (which will be the location of the pump unit), I plan to to use p clamps and surface mount the FP200. The people fitting the system say that a non switched FCU must be installed. In their pre-install literature they show a picture of a plastic flush mount FCU. Given that I am going to be using surface mount cable, shouldn't I use a surface mount metal clad box (with appropriate compression glands)?

The FCU needs to have its own C class MCB. I have told the customer that as it will be a new circuit, I am not allowed to do that part. However, I want to ensure that the electrician has everything to hand when he turns up.

I plan to use these glands for the metal clad surface mount FSU

https://www.cef.co.uk/catalogue/products/1780365-20mm-ip68-gland-red

Will the above suffice for FP200 entry in to the the new metal Hager CU?

Another concern that I have is that, from what I have read on the manufacturer's installation guide, the plasterboard must be no thicker than 14mm. The wall that will have the spray plate is 18mm ply with plastered plasterboard (about 30mm). I have already cut the opening for the box, do I need to enlarge it so that I can cut away some of the plywood? I guess that the limitation is a result of the entry of the "hose" pipe into the back box.

Thanks in advance.

 

[Adam_151]

Nothing wrong with your plan to use a metal clad accessory, however I'm not so sure that the standard unswitched spur, ideally something like this would be better https://www.cef.co.uk/catalogue/products/507112-13a-dp-key-operated-fused-spur-with-neon-metal-clad

The problem with standard spurs is a lot of them you can get the fuse out with a fingernail, where-as these are designed to be tampeproof and also provide DP isolation for those serving the thing.

https://www.cef.co.uk/catalogue/products/507112-13a-dp-key-operated-fused-spur-with-neon-metal-clad

CLA3467MR | Contactum

www.contactum.co.uk

I'm guessing the instructions say unswitched spur to guide people away from using the switched variety, but one of these is the right thing to do, its what you'd have on zoned fire alarm system, or even a FM200/novec suppression in a computer room) Just avoid the type that has the fuse as a 20mm glass fuse on the inside as they are unlikely to be upto running a pump, you wqant one that used standard plugtop/ fused spur fuses like those linked

The FP should be clipped at 300mm centres horizontally, 400mm vertically, its fire performance depends on it being correctly supported, so that when it burns, the char remains in place and keeps the conductors from shorting

 

[SUNRAY]

Personally I'd be very concerned If I was expected to work on any equipment without the ability to isolate it, in fact I'd go further and suggest switched isolation is required for emergency situations. Let's face it something designed to pump water into your property can go wrong and when it does you don't want to be standing there saying: "Oh dear me my house is getting damaged and I can't stop it." Further I'd like to see the water shutoff valve beside it.

Adams proposal is sound.

 

[opps]

Nothing wrong with your plan to use a metal clad accessory, however I'm not so sure that the standard unswitched spur, ideally something like this would be better https://www.cef.co.uk/catalogue/products/507112-13a-dp-key-operated-fused-spur-with-neon-metal-clad

The problem with standard spurs is a lot of them you can get the fuse out with a fingernail, where-as these are designed to be tampeproof and also provide DP isolation for those serving the thing.

https://www.cef.co.uk/catalogue/products/507112-13a-dp-key-operated-fused-spur-with-neon-metal-clad

CLA3467MR | Contactum

www.contactum.co.uk

I'm guessing the instructions say unswitched spur to guide people away from using the switched variety, but one of these is the right thing to do, its what you'd have on zoned fire alarm system, or even a FM200/novec suppression in a computer room) Just avoid the type that has the fuse as a 20mm glass fuse on the inside as they are unlikely to be upto running a pump, you wqant one that used standard plugtop/ fused spur fuses like those linked

The FP should be clipped at 300mm centres horizontally, 400mm vertically, its fire performance depends on it being correctly supported, so that when it burns, the char remains in place and keeps the conductors from shorting

Thanks for the informative post, especially the spacings for the clips.

They specified an unswitched FCU because of the risk of it accidentally being turned off.

 

[opps]

Personally I'd be very concerned If I was expected to work on any equipment without the ability to isolate it, in fact I'd go further and suggest switched isolation is required for emergency situations. Let's face it something designed to pump water into your property can go wrong and when it does you don't want to be standing there saying: "Oh dear me my house is getting damaged and I can't stop it." Further I'd like to see the water shutoff valve beside it.

Adams proposal is sound.

The pump unit will be under the CU, where the FCU is connected to a dedicated MCB to isolate it.

They have specified a washing machine tap to isolate the water.