Inverter supply main switch not in DB

[Dylboy]

Hello : )

Been reading but not so active sorry gents.

Will try update the other topic I had from Friday.

Went out to look at an inverter install this morning, a bunch wrong but one that I am playing bat and ball with is that the inverter supply i.e the output of the inverter it goes through a CB in the change over board but when it enters the main DB where the circuits are there is no Main Switch.

So basically to isolate the board you have to switch off the triple pole in the main DB for Eskom then go to the inverter change over board to isolate that main switch to then have the main DB isolated.

So now, if you put labels stating switch of main switch for inverter at X location is that ok ? Or must there be a main switch for the inverter output (supply) in the main DB as well so that both main switches are operated quickly and same place ?



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[Justloadit]

What about the ELU?
On what circuit has it been installed on?

[Dylboy]

Yes so the ELU was not used, told them already. So wondering if they can use the output CB as an elu. Also to split the neutrals in the DB.

Tough when someone does the job then does a runner and now stuck with a sh*t show with no thought process.

However it for me thinking for the reason of the post with the main switch not being part of the DB.

I feel that it must me in one DB to easily isolate all with out reading stickers...

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[Dylboy]

Hey all

Just a bump on this thread if anyone can help me out a bit, went to look at another house for sale and needs a CoC but again no main switch in the actual DB for the inverter supplied circuits.

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[GCE]

Hey all

Just a bump on this thread if anyone can help me out a bit, went to look at another house for sale and needs a CoC but again no main switch in the actual DB for the inverter supplied circuits.

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It would need a main switch/sub main switch to isolate power to the DB as below




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.

7.12.2.1 Where any form of alternative supply (emergency supply, UPS, other
static inverters, or wind turbine inverter generators), is connected to an
electrical installation, a notice to this effect shall be displayed at the main
switch of the installation, and where such supply
a) supplies power only to certain circuits in a distribution board, a power-on
indicator (visible or audible) shall be provided on each such distribution
board as well as a notice indicating that the standby power main switch
shall also be switched off in an emergency,
b) only supplies a part of the electrical installation, the notice shall also be
displayed on each distribution board in that part of the installation
(see 6.6.1.1(d)).
All forms of alternative devices such as invertors shall comply with the
requirements of 6.16.1.

[Dylboy]

Ah yes, issue now is that the main switch for the inverter supply is in a seperate room.. also the indicator lights are not in the DB but rather the changeover board by the inverter.

With that nearly every single install has the indicator light by the inverter and not in the DB.... New kettle of fish

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[Derlyn]

Ah yes, issue now is that the main switch for the inverter supply is in a seperate room.. also the indicator lights are not in the DB but rather the changeover board by the inverter.

With that nearly every single install has the indicator light by the inverter and not in the DB.... New kettle of fish

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This is one of my installs.

After reading the regs supplied by GCE again, I will have to go back and install a pilot light on the essentials.

[GCE]

Ah yes, issue now is that the main switch for the inverter supply is in a seperate room.. also the indicator lights are not in the DB but rather the changeover board by the inverter.

With that nearly every single install has the indicator light by the inverter and not in the DB.... New kettle of fish

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The way I read the regulations - if the D/Board is a separate essential DB it does not need to have indicator lights - Only if there is a section within the DB does it need a " visual indicator" or as it is written "supplies power only to certain circuits in a distribution board, a power-on indicator (visible or audible) shall be provided "

To me it makes sense - If I am going to work in a DB and it has a main switch that I switch off and then open the cover , everything is off and I cant get shocked . If there is one rail in the DB that is still on and requires a 2nd isolator to be switched off it will be a reminder.

The other bit I look at is , nowhere does it say 22mm pilot light or 10mm pilot light - only " power on indicator ( visible or audio ) - If I have the essential db close to the inverter , the inverter is giving me a visual indictor that it is on

We had the discussion on a large floor standing DB , 4 door, where one door was essential from a genset - The essential side had a display with voltage etc - That is a visual indicator ?

That's my opinion , not sure how you guys read it

[Dylboy]

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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[GCE]

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).