Quote Originally Posted by Dylboy View Post
Ah yes I agree with that as a visual with regards to the inverter and the change over DB and if the inverter same room as the main DB.

Second bit is I agree that if the main switch is off at the DB then there should be no power in that DB, however with this install and the other, the main switch for the inverter supplied circuits is on the changeover DB which is not in the same DB that I am working on.

I believe we can add a sticker to say to isolate the alternative power at X location but is that suffice ?

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I don't believe that a label can sort that out - If you look at 3.25 definitions it refers to one or more incoming circuits , Then 6.6.1.1 refers to main switch and the sub DB to be labelled as sub main or if the DB is label as sub DB be labelled as main switch -
So where I have one main board and a 2nd incoming supply that supply would be feeding the sub main within the same DB - That 2nd supply then becomes the sub DB and it would need to have a separate switch disconnector and shall be mounted in or adjacent to the DB in the same room ( 6.6.1.1a)

7.12.3.1.4 requires you to separate the neutrals to a separate neutral bar , 6.6.1.20 requires that you label where the supply comes from ( you cant label each CB ) and 6.9.2.2 requires live and neutral to be disconnected which brings you back in a loop and if you had D/pole CB on each circuit and labelled as 2nd supply it might be hard to argue

In short - if I read through everything it wants me to install a isolator to disconnect the incoming supply/alternative supply in or adjacent to the DB

If you get taken to court DOEL will use the OHSA to prosecute - By mixing circuits within a DB and not having a separate isolator , Will you be able to stand in front of the judge and say that you installed in " accordance with sound engineering practice " and back it up ?
The answer to that question will determine the route you take

OHSA - Electrical Machinery Regulations
Switchboards
8 (2) The employer or user shall ensure that all switchboards are selected,
designed, manufactured, installed and maintained in accordance with sound
engineering practice.



Extracts from SANS 10142 below
3.25
distribution board
switchboard
switchgear and controlgear assembly
enclosure that contains electrical equipment for the distribution or control of
electrical power from one or more incoming circuits to one or more outgoing
circuits



6.6.1.1 Each distribution board shall be controlled by a switch-disconnector
(see 6.9.4). The switch-disconnector shall:
a) be mounted in the distribution board or adjacent to the distribution board in
the same room,
b) in the case of the main or first distribution board of an installation, be
labelled as "main switch",
c) in the case of a sub-distribution board, be labelled as "sub-main switch" "or
main switch" if the board is labelled "sub-board…",
d) in the case where an alternative supply is installed (emergency supply,
uninterruptible power systems (UPS), etc.), be labelled as required in
7.12.2.1, and
e) have a danger notice on or near it. The danger notice shall give instructions
that the switch-disconnector be switched off in the event of inadvertent
contact or leakage.

6.6.1.20 The following warning labels shall be fitted to all distribution boards:
a) an indication of where the distribution board is fed from, except for single
distribution board installations. (Where the supply is derived from sources
other than the main supply, for example, generators or UPS, see 7.12.5);

6.9.2.2 In the case of a single-phase circuit, the disconnecting device shall
disconnect live and neutral. In the case of a multiphase circuit, the
disconnecting device shall disconnect all the phase conductors but need not
disconnect the neutral conductor in an installation connected to a supply
system in which the neutral conductor is earthed direct (see the TN system in
annex K).


6.9.4 Main switch-disconnectors
The main switch-disconnector on each distribution board shall be easily
accessible. (See also 6.6.1.1(b), 6.6.1.1(c), 6.6.1.6 and 6.6.1.9). If, owing to
the nature of the installation, it is necessary to be able to interrupt the supply
immediately, the switch-disconnector shall be so installed that it can be rapidly
identified and operated.

7.12.3.1.4 Where only part of an installation is switched to the alternative
supply in the same distribution board, the neutral bar shall be split
(see figures P.2 and P.3).