7.2.1.3 (b) Central system emergency evacuation lighting complying with the AS
or AS/NZS 2293 series.
Can someone explain to me what a central system is? I'm pretty new to having to deal with emergency lights. Also if not a central system, is this essentially saying none of section 7.2 applies?
Emergency lights with built in battery backup
Re: Emergency lights with built in battery backup
A "central system" is where there's one battery in a central location, with (typically) ELV d.c. subcircuits from there to the emergency luminaires. The definition is in 2293.1 .
As against a
Central systems used to be very common, so still many in service. New ones are almost unheard of these days, because it's difficult to create a central system that meets all the current requirements. Eg the e-lights for any area need to respond to loss of normal power to normal lights in that area. Also circuits passing from one fire-separated part to another need to be fire rated (note the Exception under 7.2.7.2 for wiring of single-point E/L systems).
You might wonder why this sort of thing wild get a mention in that clause of '3000'. Basically that reference is there because there's a good chance that people might just assume that a central system wouldn't need to be treated as a "safety service"; and this clause makes it clear that they must be.
The result of being classified as "evacuation equipment" is that a whole bunch of extra requirements apply to "Safety Services".
Remember also that a central system has both an incoiong supply, and outgoing subcircuits. Often the outgoing is ELV d.c - but not always. There are battery / inverter system, generator systems, etc. And even if it is ELV d.c, the rules of '3000' & relevant companion Standard(s) still apply.
So regardless of the config of the outgoing circuits to the emergency lumninaires - the extra requirements of 7.2 for "safety services" apply. So , for example, it's not acceptable to install these systems on a general power circuit; or to use bog-standard TPS - even though that's exactly how many older systems were installed.
As against a
Central systems used to be very common, so still many in service. New ones are almost unheard of these days, because it's difficult to create a central system that meets all the current requirements. Eg the e-lights for any area need to respond to loss of normal power to normal lights in that area. Also circuits passing from one fire-separated part to another need to be fire rated (note the Exception under 7.2.7.2 for wiring of single-point E/L systems).
You might wonder why this sort of thing wild get a mention in that clause of '3000'. Basically that reference is there because there's a good chance that people might just assume that a central system wouldn't need to be treated as a "safety service"; and this clause makes it clear that they must be.
The result of being classified as "evacuation equipment" is that a whole bunch of extra requirements apply to "Safety Services".
Remember also that a central system has both an incoiong supply, and outgoing subcircuits. Often the outgoing is ELV d.c - but not always. There are battery / inverter system, generator systems, etc. And even if it is ELV d.c, the rules of '3000' & relevant companion Standard(s) still apply.
So regardless of the config of the outgoing circuits to the emergency lumninaires - the extra requirements of 7.2 for "safety services" apply. So , for example, it's not acceptable to install these systems on a general power circuit; or to use bog-standard TPS - even though that's exactly how many older systems were installed.
Re: Emergency lights with built in battery backup
Thank you, this makes a lot more sense so basically central system comply with 7.2, non-central system just general requirements of 3000, am I correct in making this assumption?
Re: Emergency lights with built in battery backup
In normal practice; pretty much. But since there's no general Exception for single-point systems, would be wrong to state that none of the "safety system" requirements ever apply to them.
Better to just recognise that a central system is always a "safety system".
EL is covered not just by electrical installation standards; it's also covered by NZ Building Code [Clause F6]. On the design / install side, you need to really know what you're doing. Inspection & maintenance not so much; but all the key functional aspects have to be checked by an "independent qualified person" at least annually; and the IQP will not be able to issue a certificate of compliance to the building owner unless all I&M has been done 'by-the-book' ; 'book' being the Compliance Schedule for the particular building as issued by the local council. Usually the CS will cite '2293.2' ; even when that Standard can't actually be applied - as for very old systems installed to earlier NZS 6792, or eve - of very old - to no standard at all. This is generally a mistake by ignorant council staff; but changing it costs the owner money.
Lots of very basic systems still around that are just a mains-sensing relay and a battery with shit - quality battery charger .
When building alterations / repairs happen; E/L systems have to be maintained / altered so that they continue to comply with original rules as a minimum. But any additions will also need to comply with '3000'.
BTW; the reason for that odd reference to "AS & AS/NZS" is because while Part 2 [inspection & maintenance] is joint (AS/NZS); Part 1 [design & installation] is no longer joint (AS only). Despite this NZBC still cites Parts 1 & 3 (in modified form) as an Acceptable Solution.
Better to just recognise that a central system is always a "safety system".
EL is covered not just by electrical installation standards; it's also covered by NZ Building Code [Clause F6]. On the design / install side, you need to really know what you're doing. Inspection & maintenance not so much; but all the key functional aspects have to be checked by an "independent qualified person" at least annually; and the IQP will not be able to issue a certificate of compliance to the building owner unless all I&M has been done 'by-the-book' ; 'book' being the Compliance Schedule for the particular building as issued by the local council. Usually the CS will cite '2293.2' ; even when that Standard can't actually be applied - as for very old systems installed to earlier NZS 6792, or eve - of very old - to no standard at all. This is generally a mistake by ignorant council staff; but changing it costs the owner money.
Lots of very basic systems still around that are just a mains-sensing relay and a battery with shit - quality battery charger .
When building alterations / repairs happen; E/L systems have to be maintained / altered so that they continue to comply with original rules as a minimum. But any additions will also need to comply with '3000'.
BTW; the reason for that odd reference to "AS & AS/NZS" is because while Part 2 [inspection & maintenance] is joint (AS/NZS); Part 1 [design & installation] is no longer joint (AS only). Despite this NZBC still cites Parts 1 & 3 (in modified form) as an Acceptable Solution.
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gregmcc
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Re: Emergency lights with built in battery backup
The whole IQP thing can be a nightmare to deal with as an IQP registered person in one area - Auckland for example will not be registered for the Waikato area. Saying that you dont have to be IQP registered to install EL but to check compliance with the Building code you do. As EL is a specified system the design has to be done by a suitably qualified person and during installation the lights have to be right where the design says they should be otherwise the IQP may fail the inspection.
As far as maintaining - log books (electronic or hard copy) are required to prove maintenance, the bigger the building the bigger the job, big buildings can become a nightmare very quickly, I used to look after the EL's in a Hospital, many thousands of EL's and the whole thing was a mess when I took over, I was an IQP at the the time I had to issue several fails which meant their Building WOF's failed. They eventually got the message and decided that they were better spending some money fixed them right rather than failing the BWoF's
As far as maintaining - log books (electronic or hard copy) are required to prove maintenance, the bigger the building the bigger the job, big buildings can become a nightmare very quickly, I used to look after the EL's in a Hospital, many thousands of EL's and the whole thing was a mess when I took over, I was an IQP at the the time I had to issue several fails which meant their Building WOF's failed. They eventually got the message and decided that they were better spending some money fixed them right rather than failing the BWoF's
Re: Emergency lights with built in battery backup
For some reason it's always the IQP who's a bastard for declining to issue a CoC come end-of-year.
Non-compliant design & installation, lack of adequate records, and slack maintenance never seem to be blamed;
let alone owners with gorse in their pockets.
Not just for E/L, but also for other SSs.
Non-compliant design & installation, lack of adequate records, and slack maintenance never seem to be blamed;
let alone owners with gorse in their pockets.
Not just for E/L, but also for other SSs.