Fire panel wiring

[vernam616]

Hi all

Does anyone know if its ok to wire from the DB to fire alarm panel in standard 2.5 twin or does the supply need to be fire rated (pyro/fp200)?

Thanks in advance

 

[telectrix]

not sure if it's mandatory, but for several years, every fire alarm panel has, to my knowledge, been wired in FP200 or MICC. i generally use the same 1.5mm FP200 that i use for the zones/sounder circuits.

 

[Kamikaze]

Yes, FP200 or pyro and don’t forget a red key switch by the side of the panel.

 

[telectrix]

keyswitch or unswitched FCU?

 

[Kamikaze]

Key switch mate! We are changing loads of unswitched spur for them as we come across them. There is probably a regulation for it but I don’t know it.

 

[telectrix]

i suppose the reason is to provide isolation for testing, without leaving a removable fuse for numpties to pull out. where then, though , does the 3A fuse go?

 

[gkk]

Yes, as per NFPA72, the power supply cable to fire alarm panel must be fire rated,same as FP200. gk

Hi all

Does anyone know if its ok to wire from the DB to fire alarm panel in standard 2.5 twin or does the supply need to be fire rated (pyro/fp200)?

Thanks in advance

 

[gkk]

Dear telecrix

Sure. NFPA72 requires power supply cables to fire alarm panel to be fire rated same as FP200 etc. gk

 

[telectrix]

that's what i thought, but not having bs5839 or other fire alarm regs., was not 100% sure if it was mandatory.

 

[vernam616]

Thanks for the input

 

[myristate]

Extract from BS5839 pt1 2002

All systems need to be wired in fire resistant cable, junction boxes, clips and terminations. Some domestic (BS 5839-6) systems need to comply with BS 5839- 1. These are Grades A and B systems. These systems also require fire resistant wiring.

25.2 Recommendations for mains power supplies

25.2 c) 'To facilitate local isolation during maintenance, suitable means should be provided for the double pole isolation of the low voltage supply circuit that serves the power supply and the control equipment(see 29.2e)'

29.2 Electrical safety recommendations

29.2 e) ' Means should be provided for double pole isolation of the mains supply to all parts of the system; the isolation facilities should be suitably sited , in the vicinity of the equipment served, for use by maintenance technicians without the need for access to remote parts of the building. It should be possible to lock the facilities in both the normal and isolate positions to prevent unauthorised use. See Clause 25.'

29.2 f) 'Every isolator, switch and protective device that can isolate the supply to the fire alarm system, other than the main isolator for the building, should be labelled either;
FIRE ALARM; Protective device serving only the fire alarm with no switch
FIRE ALARM, DO NOT SWITCH OFF; in the case of a switch (whether incorporating a protective device or not) that serves only the fire alarm circuit.

29.2 g) Every isolator, switch and protective device that is capable of disconnecting the mains supply to the fire alarm system should be situated in a position inaccessible to unauthorised persons or be protected against unauthorized operation by persons without a special tool

Note 4 A special tool, may for example, be a key actuator (sometimes called "secret key") for a mains switch device.



So to summarise, Wired in fire resistant cable, requires double pole spur with key most use the fish tail keys and it needs to have marked on the face plate "FIRE ALARM, DO NOT SWITCH OFF"

 

[Kamikaze]

Splendid! That settles that then…lol
One never knows whether some engineers are on some sort of windup. They make us do all sorts of things at work. Cables have to be P-clipped or if on catenary’s & tray work have metal tie wraps every meter. If the down drops are in YT trunking the cables have to be buckle clipped inside the trunking. I swear they make all this stuff up.

 

[myristate]

We sub contracted a PFI secondary school out to an electrical contractor. They did a great job of wiring the 1000+ detection points it was very neat however they had used plastic cable ties everywhere. When it was inspected by us about three months in we told them to change them to metal cable ties as it was never going to pass inspection at the end. In the end they never and at the end it was flagged. They spent six weeks putting it right which was made a lot worse by the fact all the lagging and false ceilings were fire sealed. Some security installers do not bother with some of the particulars of BS5839 which is scandalous this seems to create a mixed feeling among electrical contractors as to what is the correct regs as I have often heard people mention "we did not do it like that on that job and it was passed inspection" I very much like to carry around a copy of the BS5839 fire regs to show electrical contractors.

 

[Kamikaze]

Personally don’t do that many fire alarm jobs. On the rare occasion that we do get the honours, the installation lads do all the donkey work. Our fire alarm guy’s then rock onto the site with their laptops and sound meters, program the panels and commission the system and steal all the glory. The problem is, the company won’t send us on a fire alarm course because apparently there isn’t a universal one. We would have to do one for every make of panel. Mind you, you got to give it to the fire alarm guy’s, they know where every “Greggs” is in the county is. Must be part of the coursework.

 

[myristate]

While each manufacture of fire panel does have their own course for there particular panels. There is absolutely BS5839 training available that covers all the stuff you need to know. As for fire panels we are a Gent integrator so use a lot of there equipment but we use Morely panels a lot because most councils/police forces do not want closed protocol panels. their panels are very simple to commission, A monkey could do it. The ability to make sure stuff is compliant with BS is where the real art lies as you have to sign that off. Don't want to go down for manslaughter