# Forum More Stuff Debate & Technical Discussion  Electrical Switchboard questions.

## Bedford

Hi Folks,  
I have attached pics of two sub boards from two different installations. 
I would like you opinions as to whether one or both are compliant. 
My concern is that the main switch in the second pic does not isolate the oven circuit, which could lead someone into a false sense of security. This is in a new home. 
The main isolator in the first pic does turn everything off. 
Thanks for any responses, and feel free to move this Mr Watson, if it should have been in Electrical. :Smilie:

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## watson

Nope....right place.  Go for it!

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## chrisp

Bedford, 
AS/NZS 3000:2007 states the following (in part):  *2.3.3.2 Number of main switches*
The number of main switches shall be kept to the minimum practicable to provide for effective operation in an emergency. 
Domestic electrical installations, including each separate domestic electrical installation forming part of a multiple electrical installation, shall be provided with not more than one main switch for
(a) each separately metered supply; or
(b) where there is more than one separately controlled supply from a meter, a main switch for each of the separately controlled supplies. (and...)  *2.3.3.4 Identification*
Main switches shall be identified as follows:
(a) Each main switch shall be marked MAIN SWITCH and shall be readily distinguishable from other switchgear by means of grouping, contrasting colouring or other suitable means to provide for prompt operation in an emergency.
(b) Where there is more than one main switch, each main switch shall be marked to indicate the electrical installation or portion of the electrical installation it controls.
(c) Where the opening of a main switch brings into operation or isolates an alternative supply, a notice shall be provided to indicate the position of the main switch controlling the alternative supply.
(d) Where supply is provided at more than one point in any building, a prominent notice shall be provided at each main switchboard, indicating the presence of other supplies and the location of other main switchboards.
NOTE: Marking requirements for other switches are contained in Clause 2.3.4.4.I'd say the one with the separate switch for the oven it doesn't comply - especially since it has a label that says "Main Switch" and it isn't *the* mains switch!   
But, it would be easily fixed by adding another separate isolator to cover the whole board - there is room on the board.

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## Bedford

Thanks Chrisp, I thought you'd have the Big Book :Smilie:    

> AS/NZS 3000:2007 states the following (in part):*2.3.3.2 Number of main switches*
> The number of main switches shall be kept to the minimum practicable to provide for effective operation in an emergency.

   I assume this would have to be accessible to the occupant?   

> Domestic electrical installations, including each separate domestic electrical installation forming part of a multiple electrical installation, shall be provided with not more than one main switch for
> (a) each separately metered supply;

   The sub board in question is one of three units on a block, with a common metering position (all separately metered), and in a locked cabinet. I'm not sure if there is a main switch in there or just a service fuse. I'm wondering (if there is a main switch there) if the Sparkie considered that it complied with the regs, but didn't allow for the locked cabinet?    

> I'd say the one with the separate switch for the oven it doesn't comply - especially since it has a label that says "Main Switch" and it isn't *the* mains switch!   
> But, it would be easily fixed by adding another separate isolator to cover the whole board - there is room on the board.

  The first pic is from a different installation (150 kilometers away, for comparison) I'll try to get a look at the other boards of unit 1 and 3 to see if they're the same, not that easy as none of them are mine, but unit 2 belongs to a friend and member here. 
There was a Certificate of Electrical Compliance issued at the hand over to the first and new owner. 
What would be the next course of action, if any?

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## chrisp

> What would be the next course of action, if any?

  Bedford, 
I suspect you know much as I on this.  Others may have additional valid ideas. 
The Standard is quite clear to me, but it comes down to the definition of "minimum" and "effective".  
I see two options:  The first option, but not my preferred, would be to call the relevant State electrical/energy authority and carefully corner them into answering your question.  I suspect they are very industry biased and are likely to side with the electrician rather than the consumer.  (In my opinion) You'd have to have them 'over the ropes' for them to act on your behalf. 
The other option is to contact an electrician and just state that you want a single isolator switch fitted and quote the above standards if required.  Ideally, you'd contact the electrician who wired it and they may do it free of charge (under the threat of option one above  :Wink:  ).To me, the label "Main Switch" is your main leverage on this one - it isn't a main switch.  I suspect, if the label is removed, it could be argued to comply (in 'letter' but not 'intent'). 
In the end, I think you (or your friend) needs to have it fixed - it isn't apparent that there are two switches that need to be switched off to fully isolate the installation.  Argue who bears the cost separately to the main switch issue. 
BTW, if there was a fire, the fire service will pull the service fuse.  The service fuse is usually at the point of attachment (for aerial cables) and is pulled with an insulated pole.  It isn't something the consumer needs to be concerned about.  The fire brigade will ensure that the power is disconnected before hosing down a fire. 
Chris  :Smilie:

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## iconnect

> Thanks Chrisp, I thought you'd have the Big Book I assume this would have to be accessible to the occupant? 
>  The sub board in question is one of three units on a block, with a common metering position (all separately metered), and in a locked cabinet. I'm not sure if there is a main switch in there or just a service fuse. I'm wondering (if there is a main switch there) if the Sparkie considered that it complied with the regs, but didn't allow for the locked cabinet?  The first pic is from a different installation (150 kilometers away, for comparison) I'll try to get a look at the other boards of unit 1 and 3 to see if they're the same, not that easy as none of them are mine, but unit 2 belongs to a friend and member here. 
> There was a Certificate of Electrical Compliance issued at the hand over to the first and new owner. 
> What would be the next course of action, if any?

   

> Hi Folks,  
> I have attached pics of two sub boards from two different installations. 
> I would like you opinions as to whether one or both are compliant. 
> My concern is that the main switch in the second pic does not isolate the oven circuit, which could lead someone into a false sense of security. This is in a new home. 
> The main isolator in the first pic does turn everything off. 
> Thanks for any responses, and feel free to move this Mr Watson, if it should have been in Electrical.

  Bedford and Chrisp, 
I'm in a little late in on this topic but I saw it whilst looking up some standards as practice for an upcoming exam.
My take is the 2nd installation fails to comply on a number of grounds 
reason a).
2.3.3.1 General
The supply to every electrical installation shall be controlled on the
main switchboard by a main switch or switches that *control the whole
of the electrical installation* 
then as Chrisp pointed out 
2.3.3.4 Identification
Main switches shall be identified as follows:
(a) *Each main switch shall be marked ‘MAIN SWITCH’* and shall be
readily distinguishable from other switchgear by means of grouping,
contrasting colouring or other suitable means to provide for prompt
operation in an emergency 
reason b). 
2.3.3.3 Location
Main switches shall be accessible as follows
(b) Electrical installations with more than one occupier *Each individual
occupier shall have ready access to an isolating switch or switches
that isolate that occupier’s portion of the electrical installation.* 
reason c). 
2.6.2.1 General
Any device for the provision of additional protection shall be capable of
interrupting the part of the circuit protected by the device when an earth
leakage current is above a predetermined value. *The load current rating of an RCD shall be not less* than the greater of the
following—
(a) *the maximum demand of the portion of the electrical installation being
protected by the device;* 
- I suspect with 2 power, 2light and an air con the max demand for that RCD would be greater than 40A, but going on a limitation calculation it definitely will not break the  maximum current 
Reason d).(if the installation was post AS300:2007 edition) 
2.6.2.4 Arrangement
Where additional protection of final subcircuits is required, in accordance
with Clause 2.6.3, the final subcircuits shall be arranged as follows:
(b) In residential installations—
(i) *not more than three final subcircuits shall be protected by any
one RCD; and
(ii) where there is more than one final subcircuit, a minimum of two
RCDs shall be installed*  
So in short I would
A. install a main switch controlling that particular unit 
B. Label main switch as such
C. Install an RCD for each final sub circuit (2 power, 2 light)
D. Check the other units as well as the main switchboard to ascertain the protection status of the submains to each board 
Without opening up the board and inspecting the rest of the installation they would be my first things to rectify. 
Did you get this sorted out and if you did what was the outcome? 
regards
Darryn

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## Bedford

G'day Darryn, thanks for the reply to the question, unfortunately I'm not certain what the end result was, the owner has not mentioned it to me since. :Smilie:

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