retrospective application of standards

[Chris Houston]

Mark,

I hope the system complies with the signs and signals regualtions - there is a requirement for all safety signals to have battery back up.  This is not a "recommendation" or a standard or guidance, but a legal requirement of all safety signaling systems, irrespective of when they were installed.

[colin todd]

This is probably not a fire safety issue but an engineering one. It is for the risk assessment to determine whether there is a credible scenario of fire shorting a circuit before it is detected and latched. Once the staff are aware and are dealing, failure of sounder circuits might not bring serious risk. EMC is probably the greatest problem with a new addressable system on existing PVC/PVC wiring. Wee B is right, in that we changed it for detector circuits simply to reflect custom and practice, rather than because of a major worry about loss of circuit integrity.

[nearlythere]

Mark,

I hope the system complies with the signs and signals regualtions - there is a requirement for all safety signals to have battery back up.  This is not a "recommendation" or a standard or guidance, but a legal requirement of all safety signaling systems, irrespective of when they were installed.

Where is this bit in the regs Chris?

[Graeme]

it's in the H&S (safety signs and signals) regs 1996

page 32  paragraph 8

[Galeon]

Graeme's, point above is very important. Graeme's contributions on this forum are often short and to the point, but they are invariably spot on.

To expand on Graeme's post:

Disregarding the current BS recommendation's disallowing the use of pvc/pvc cable, you would still have to use an addressable system that can cope with pvc/pvc cable - if such exists! The capcitance of the cable along with the electrical shielding all play a part in the ability to send understandable addressable data pulses along it.

You'd be well in the s**t if you installed an addressable system on to existing pvc/pvc cable and then it didn't work properly. That would be a waste of money!

I tend to find that Hochiki is extremely bullet proof when it comes to old cabling , we have never encountered a problem on some old  c*ap wiring we have had to deal with over the years.
Personally you could change it over and phase in over a period of agreed time fp to replace it , so at least it can be budgeted for and then everyone's a winner.

[Allen Higginson]

it's in the H&S (safety signs and signals) regs 1996

page 32  paragraph 8

Bells are classed as acoustic signage and so have to have back up.

[nearlythere]

it's in the H&S (safety signs and signals) regs 1996

page 32  paragraph 8

Can't find anything about batteries Graeme. Can you quote the paragraph text please?

[Graeme]

Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut.

A fire sign is defined as a sign including an illuminated sign or acoustic signal which gives warning in case of a fire.

Fire alarms are included in the term acoustic signal.

[Tom Sutton]

http://www.opsi.gov.uk/si/si1996/Uksi_19960341_en_2.htm

schedule 1 : part 1 : regulation 8

[nearlythere]

Signs requiring some form of power must be provided with a guaranteed emergency supply in the event of a power cut.

A fire sign is defined as a sign including an illuminated sign or acoustic signal which gives warning in case of a fire.

Fire alarms are included in the term acoustic signal.

Still can't see anything about batteries.

[Graeme]

A guaranteed emergency supply is the batteries

[Tom Sutton]

Still can't see anything about batteries.

I agree it is doesn’t say batteries or instantaneous and although batteries would be the first choice, a power generator would meet the conditions of that clause.

[nearlythere]

Do we agree that required signs don't have to have battery back up?
What about powered signs which do not have to be there? Does one only have to provide emergency power to signs which are required to be powered?

[Tom Sutton]

I do agree but what would you use as a guaranteed emergency supply in the event of a power cut. I would imagine if the hazard has been eliminated then you would not require a sign therefore you do not need backup power.

[nearlythere]

I do agree but what would you use as a guaranteed emergency supply in the event of a power cut. I would imagine if the hazard has been eliminated then you would not require a sign therefore you do not need backup power.

Firstly TW I would assess if the sign was neccessary and if so if it is needed to be power. If this was so I would consider the circumstances and all back up options. As you say a standby generator could be used. I have recommended this for an outdoor concert.
It seems to be normal now for illuminated exit signs to be provided where a simple stick on sign would be adequate. I have also found it normal to see illuminated exit signs over final exit doors from buildings even when some are not required for escape purposes.
To me this is a blitz approach because installers don't know when they are not needed. IMHO