Hi,
Just a question about ESR 59 (3)(b) in relation to AS/NZS 3000:2007 2.6.3.4.
I've always been under the assumption that if all the of the circuit protection was replaced on a SwitchBoard (Fuses to MCB) then RCD protection needs to be included on circuits that require RCD protection.
But someone has pointed out that ESR 59 (3)(b) says you don't need to (Maintained to Original Condition)
My view is that the SwitchBoard isn't being Maintained to its Original Condition, so AS/NZS 3000:2007 2.6.3.4 must be followed.
What are your thoughts on this?
ESR 59 (3)(b) VS AS/NZS 3000:2007 2.6.3.4
Re: ESR 59 (3)(b) VS AS/NZS 3000:2007 2.6.3.4
I’ve had the same thoughts on this topic before too.
I guess there’s a good argument that if you’re replacing all the MCBs on a switchboard by replacing the switchboard, you’re ‘maintaining in the original condition’. Probably gets a little more murky to say it’s ‘maintenance’ if you’re replacing SERFs for MCBs.
My thoughts are, it’s better to err on the side of caution and just fit RCDs, any good spark would anyway.
I guess there’s a good argument that if you’re replacing all the MCBs on a switchboard by replacing the switchboard, you’re ‘maintaining in the original condition’. Probably gets a little more murky to say it’s ‘maintenance’ if you’re replacing SERFs for MCBs.
My thoughts are, it’s better to err on the side of caution and just fit RCDs, any good spark would anyway.
Re: ESR 59 (3)(b) VS AS/NZS 3000:2007 2.6.3.4
NZ law has a general principle that there are no mandatory upgrades, though there are occasional exceptions to that.
ESR 113 enshrines this principle. and so does ESR 59 (3)(b).
In particular, the "maintain in original condition" provision allows us to replace an old, degraded, SERF with a brand new SERF (assuming you can find one).
It's open to argument whether replacing the SERF with a different type of overcurrent protection device is "maintaining in original condition".
If you look at ESR 113; there are 3 conditions for allowing something to remain in service
- complied when installed;
- still complies with original requirements; and
- not electrically unsafe.
Back when the SERF was installed, there were different requirements that applied for different types of overcurrent protection.
These differences affected both the relationship between cable size & device rating, and also (for example) that only a max of 2 sockets were permitted on a SERF-protected circuit.
So if we are changing from a SERF (classed as "coarse protection") to an mcb ("close protection") we're no longer complying with the original requirements. So from that viewpoint we're arguably not maintaining in "original condition".
We're changong the circuit from one previcded with coarse protection, to one provided with close protection, to which different rules would have applied at the time of original installation.
Therefore as far as ESR 113 is concerned, the circuit may no longer comply with original requirements.
In which case, the option of ESR 59(3)(b) isn't available, and instead we probably have to use option (a): i.a.w "3000"
ESR 113 enshrines this principle. and so does ESR 59 (3)(b).
In particular, the "maintain in original condition" provision allows us to replace an old, degraded, SERF with a brand new SERF (assuming you can find one).
It's open to argument whether replacing the SERF with a different type of overcurrent protection device is "maintaining in original condition".
If you look at ESR 113; there are 3 conditions for allowing something to remain in service
- complied when installed;
- still complies with original requirements; and
- not electrically unsafe.
Back when the SERF was installed, there were different requirements that applied for different types of overcurrent protection.
These differences affected both the relationship between cable size & device rating, and also (for example) that only a max of 2 sockets were permitted on a SERF-protected circuit.
So if we are changing from a SERF (classed as "coarse protection") to an mcb ("close protection") we're no longer complying with the original requirements. So from that viewpoint we're arguably not maintaining in "original condition".
We're changong the circuit from one previcded with coarse protection, to one provided with close protection, to which different rules would have applied at the time of original installation.
Therefore as far as ESR 113 is concerned, the circuit may no longer comply with original requirements.
In which case, the option of ESR 59(3)(b) isn't available, and instead we probably have to use option (a): i.a.w "3000"