Do circuit breakers need to be SABS APPROVED

[RegElec]

I must comment on the main switch.

I am not sure about different parts of the country but in KZN east coast the meter box has a circuit breaker feeding the installation which offers protection for the supply cable. Therefore any combined DB load over the circuit breaker rating (normally 60A for a domestic installation) the meter box circuit breaker will trip. By having a mains circuit breaker installed at the DB all that will be accomplished is that it may be more convenient to have the breaker trip at the house rather than the suppliers side. However, having the switch at the DB doesnt always mean it will trip there and not at the suppliers side.

As far as I am aware SANS does not require another mains circuit breaker at the DB, only a double pole disconnector.

I also noticed that there is a surge arrester installed - not a requirement but may be beneficial.

[bergie]

on a normal db and sub db it is acceptable to have your overload protection upstream, but outside meter boxes are not meant for the user to go reset circuit breakers etc.
that would probably be a supplier requirement and not a sans requirement.

[RegElec]

Perhaps it is different in different parts of the country. Down here the meter box has a rod out the bottom of the box with the other end over the circuit breaker lever for the purpose of switching the breaker on should it trip.

[ACEsterhuizen]

SANS 10142 does not dictate directly for a main circuit breaker (over current protection or OPD) to be mounted inside the consumer DB Box. Here are the criteria though: (it does however, compel the installation of a switch-disconnector in or adjacent to the consumer db board) In fact, if a Circuit Breaker does not comply with Clause 4 for Switch Disconnectors, it shall not be used a switch disconnector:

Clause 4:

Circuit-breakers used
as switch-disconnectors
(isolators) In < 125 A and Icu < 10 kA VC 8036a plus 4.8 of SANS 152d, or
VC 8036a plus SANS 60947-2
(ed. 2.1 or later ed.) (It must have that certification^^^)
Circuit-breakers used
as switch-disconnectors
(isolators)
In < 125 A and Icu > 10 kA SANS 556-1, or
SANS 156e plus 4.8 of SANS 152d, or
SANS 60947-2 (ed. 2) plus 4.8
of SANS 152d, or
SANS 60947-2 (ed. 2.1 or later ed.)
Circuit-breakers used
as switch-disconnectors
(isolators)
125 A < In < 1 000 A SANS 556-1, or
SANS 156e plus 4.8 of SANS 152d, or
SANS 60947-2 (ed. 2) plus 4.8 of
SANS 152d, or
SANS 60947-2 (ed. 2.1 or later ed.)
Circuit-breakers used
as switch-disconnectors
(isolators)
1 000 A < In SANS 556-1, or
SANS 60947-2 (ed. 2) plus 4.8 of
SANS 152d, or
SANS 60947-2 (ed. 2.1 or later ed.)

6.8 Circuit-breakers:

6.8.1 Circuit-breakers used as main or local switch-disconnectors

A circuit-breaker that is used as a main or local switch-disconnector (see
6.9.4) shall comply with the relevant requirements of a standard given in
clause 4 for switch-disconnectors, or, alternatively, a switch-disconnector
shall be positioned on the supply side of the circuit-breaker.

6.7.1.3 Conductors that form part of an installation may be protected by
the supplier's overcurrent protective device, provided that:

a) the supplier agrees,
b) the supplier’s protective device complies with clause 4, (all the tables)
c) the user has access to the device, and
d) such protective device complies with the requirements of 6.7.2.1.

6.7.2.2 Except as allowed in 6.7.2.3, an overload protective device shall
be installed:

a) along a conductor where the current capacity of the conductor is
reduced,
b) where the thermal rating of a disconnecting device could be exceeded
(summation of ratings), and
c) where the thermal rating of an earth leakage protection device
not provided with integral overcurrent protection, could be exceeded.

6.7.2.3 The overload protective device may be installed at any point in
the conductor run that it protects, provided that:

a) there is no branch circuit or socket-outlet between the point where
there is a reduction in the conductor's current-carrying capacity and
the point where the device is installed, and

b) the entire length of the conductor is protected against short-circuit,

or

c) the conductor is:
1) of length not exceeding 5 m,
2) so installed as to minimize the risk of overload or fault in its
operating condition,
3) not near flammable materials, and
4) not likely to cause harm to a person in the event of a fault.

and as for "disconnecting devices" for each installation:

6.9.1 General

6.9.1.1 Each installation shall have one disconnecting device to
disconnect the entire installation, except in the case of multisupplies or
more than one transformer supplying the installation where each supply
shall have its own disconnecting device. There shall be a notice fixed next
to each such disconnecting device indicating that the installation has
more than one main switch-disconnector.

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.

imho. (and applicable to "new" installations)

[Gilberto Silva]

Thank you guys. I've had no electricity for 3 days, as things couldn't get better, not due to my installation though
I did send the images to CBI, over the phone he did say that they are not branding all their circuit breakers. I'll paste what he said in a email, but he did also mention over the phone that their is specific things in the circuit breakers that he would know definitely its CBI parts but couldn't divulge those details to me. Here goes his email to me

Hi Gilberto,
Thanks for contacting CBI.
Based on what I see in the photos these units do appear to be our units.

Interestingly on the list value of the units, the value is R2043-00 ex vat.

I do have a concern that there does not appear to a main circuit breaker offering overall over-current on the DB?
There might well be a municipal circuit breaker which would trip on these events but I don’t believe this to be convenient or legal?
"

[AndyD]

I think you can take it that they're the genuine item then and they're not necessarily displaying their SABS compliance on the actual product although I couldn't for the life of me begin to guess why not.

Their concerns around the lack of main circuit breaker were similar to mine although it is plausible the Eskom protection could fulfill the requirements under certain circumstances. I think the problem with relying on the Eskom MCB for DB overload protection is that there's nothing to stop it being replaced or even being removed by Eskom at any given time if there was alterations to their network for example.

[MullerR]

Their concerns around the lack of main circuit breaker were similar to mine although it is plausible the Eskom protection could fulfill the requirements under certain circumstances. I think the problem with relying on the Eskom MCB for DB overload protection is that there's nothing to stop it being replaced or even being removed by Eskom at any given time if there was alterations to their network for example.

6.8.1 Circuit-breakers used as main or local switch-disconnectors

A circuit-breaker that is used as a main or local switch-disconnector (see
6.9.4) shall comply with the relevant requirements of a standard given in
clause 4 for switch-disconnectors, or, alternatively, a switch-disconnector
shall be positioned on the supply side of the circuit-breaker.

Please correct me if I interpret it wrong. According to 6.9.4 if you use a circuit breaker as a switch disconnector, it must comply with clause 4 for switch disconnectors, BUT if not, a switch disconnector shall be positioned on the Supply side of the Circuit breaker, thus meaning it shall be installed on the incoming side of the circuit breaker. (Supply side = Incoming, Load Side = Outgoing). So the arrangement will be Switch Disconnector, Main Circuit Breaker and then the rest of the circuit breakers for the installation? So my confusion is why is it allowed in certain areas that the upstream supply breaker can be used as the circuit breaker for OC faults if 6.9.4 states the switch disconnector must be installed on the supply side of the circuit breaker? As Bergie Mentioned:

on a normal db and sub db it is acceptable to have your overload protection upstream,

, are these two regulations not contravening one another, OR am I interpreting the Supply side of Circuit breaker wrong?

[AndyD]

Please correct me if I interpret it wrong. According to 6.9.4 if you use a circuit breaker as a switch disconnector, it must comply with clause 4 for switch disconnectors, BUT if not, a switch disconnector shall be positioned on the Supply side of the Circuit breaker, thus meaning it shall be installed on the incoming side of the circuit breaker. (Supply side = Incoming, Load Side = Outgoing). So the arrangement will be Switch Disconnector, Main Circuit Breaker and then the rest of the circuit breakers for the installation? So my confusion is why is it allowed in certain areas that the upstream supply breaker can be used as the circuit breaker for OC faults if 6.9.4 states the switch disconnector must be installed on the supply side of the circuit breaker? As Bergie Mentioned: , are these two regulations not contravening one another, OR am I interpreting the Supply side of Circuit breaker wrong?

From my understanding the switch disconnector would only be required to be upstream of the main OCPD if both items are within the DB because it's the DB that requires 2-pole disconnection.

[ACEsterhuizen]

What is more worrying is that none of the "major" manufacturers can supply authenticated documentation of:

Please send me the certification for your following CIRCUIT BREAKERS please:
Circuit-breakers used as switch-disconnectors (isolators) In < 125 A and Icu < 10 kA

VC 8036a plus 4.8 of SANS 152d,

or

VC 8036a plus SANS 60947-2

(From Clause 4 (SANS 10142) (Circuit breakers used as switch disconnectors)

Not one has come back with documentation.

CBI, Schenker or LEAR circuit breakers cannot be used as Switch-Disconnectors then?

So if their c/breakers are not compliant to be used as switch disconnectors (which are required by regs) does that mean that most installations does not comply? (Where there is ONLY a circuit breaker and no switch disconnector or "6.9.1.1 - disconnecting device"

MAKE SURE YOU KNOW THE The difference.

[AndyD]

All manufacturers should be able to supply compliance documentation for their circuit breakers or they should state that they're not rated as switch disconnectors. Maybe try communicating with them again a little more assertively by pointing out it's a legal requirement this documentation is supplied on request.

Something else that struck me as being odd was in Gilberto's previous post he stated;

.......but he did also mention over the phone that their is specific things in the circuit breakers that he would know definitely its CBI parts but couldn't divulge those details to me.........

So CBI are basically keeping info on how to spot counterfeit items as trade secrets and even when there's a specific suspicion raised they're not telling customers how to spot a fake. How does that work? All the major players in most industries have entire web pages and published fact sheets available on how to spot pirated or fake items yet Gilberto's comment suggests CBI's policy appears to be the exact opposite.

Here's a few examples of counterfeit info from several companies;
Clipsal
Schneider
Eaton

I see there's some info here on counterfeit MCB's but I'm not sure if it was officially provided by CBI.

[MullerR]

From my understanding the switch disconnector would only be required to be upstream of the main OCPD if both items are within the DB because it's the DB that requires 2-pole disconnection.

So my understanding is also correct by implying that the double pole isolator should be installed before the circuit breaker.

Now I have another point. Most circuit breakers have the symbol which is not suitable for isolation according to SANS 10142, Table Q1, but the symbol according to SANS 10142, Table Q1 suggests it is suitable for Isolation? Does that mean when you install a double pole circuit breaker with the symbol suitable for isolation, it is allowed to be used as the switch disconnector?

[AndyD]

........Does that mean when you install a double pole circuit breaker with the symbol suitable for isolation, it is allowed to be used as the switch disconnector?

As I understand it that symbol means it is capable of being used as a switch disconnect assuming it has sufficient poles for that particular installation. Also the green toggle on a CBI MCB or SP+N denotes it as an isolator or switch disconnector. TBH I haven't seen an MCB in a long time that doesn't qualify as a switch disconnector, from what I remember the device needs to have positive forced disconnection of the internal switch contacts when it trips and also a certain gap between the contacts when they're in the open position. There may be other requirements as well but I think nowadays most of the major MCB suppliers are fulfilling these requirements with their standard OCPD's such as MCB's and SP+N's etc making them dual purpose.

[ACEsterhuizen]

Switch symbols: The horizontal line in the switch symbol of the contacts indicates that they fulfill the isolating function.