PV and SANS Compliance

So, after some time, I finally decided that I need to point out a few “points” in SANS10142 that has to do with PV installation compliance.

I have now had a few electricians making a statement that SANS does not cover DC or PV installations… This is becoming a problem for me, as it clearly does and most electricians issuing a CoC does not know what’s going on!

The problem with DIY PV installations is that they are illegal, if you read the Acts and Regulations regarding electrical installation, it clearly states that these installs have to be done by a qualified person.

I am not going to address the DIY solutions here… What I want to point out is a few “problems” that keep jumping out when dealing with compliance, and I am open to discussion to see if the interpretation I have is the correct one…

So let’s jump in:
[Format will be “Statement” and then a separate ("|") and pointing to clauses (if available)

  1. AC and DC conductors shall not be in the same trunking | 6.1.10, 3.85, 6.1.7,6.4.1, good practice
  2. Protection devices shall be DC rates (see other post, very well explained) | 7.5.1.1
  3. Correct protection and cable selection for batteries | 7.15.1.1
  4. All DC cables must be labelled accordingly | Clause 7.12.x somewhere
  5. The neutral shall not be earthed beyond an earth leakage | 7.16.4.5
  6. a TN-S system shall not be converted to a TN-C system | 7.16.4.6
  7. If a system is a hybrid and can operate in island mode, the earth leakage on the plug circuits shall be tested when inverter is islanded. Where applicable a earth-neutral bond (via relay) shall be installed to ensure proper operation of the earth leakage during grid loss events. | Clause 7.12.3
  8. Notice/Labelling to indicate alternate supply, this includes that all “back-up” circuits be specifically and clearly labelled. | Clause 7.12.2.1
  9. Alternate supply short circuit current taken into account with main incoming short circuit currents | Clause 7.12.2.3
  10. Earth Leakage installed after the inverter output | Clause 7.12.2.6
  11. Correct Surge Protection has been installed on all DC and AC components as required by the lightning risk assessment
  12. Neutral bar shall be split between council supply and on-site supply | Clause 7.12.3.1.4
  13. Solar panel frame and structure shall be bonded to the consumer earth | Clause 7.12
  14. Where single core conductors are used, such conductors for each circuit shall
    be tied together at intervals to ensure identification, unless another suitable
    arrangement is employed. | Clause 7.12
  15. All DC (string cables) to be in conduits or where applicable affixed to the structure (no matter if they are UV rated)
  16. All DC string cables to be labelled accordingly and voltage levels indicated on both the cable ends and the Distribution board. Note both operating voltage (max) and allowable voltage for the system on the DB board.
  17. In addition it shall be recognised that the supply from each inverter,
    battery arrangement and PV panel (or identified clustered group), constitutes
    a supply, and requires arrangements similar to point of supply, which shall
    include switch-disconnection arrangements and shall comply with 7.12.5.
  18. Does the CoC specifically include mention of the Alternative Supply? Has all the appropriate boxes been ticked and the description made specific to in the PV installation?

This is not an exhaustive list on SANS10142, but a few points that is not covered by most installs. I have one in bold there that might cause a lot of discussions (it was copied verbatim out of the code)…

So, if you are doing installs or getting a sparky to check the installations, please consider the few points above. With the CoCT sign-off by a Pr. Eng requiring the engineer to sign-off on the SANS compliance, it can become a bit sticking point…

I feel that point 1 and point 6/7 will be one of the bigger discussion points, with quite a few opposing views on these ones.

I had a supplier specifically state that you must do a hardwire on the E-N on the Ohm (Sunsynk) inverter output… Well, SANS does have other opinions on that matter…

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I don’t think we’ve argued about TN bonding yet on this side of the forum divide :slight_smile:

Also, we’re fairly heavy on the blue side of things, and the blue inverters do a relay test and often cause people a lot of heartache as it exposes existing issues, shortcuts and the occasional couldn’t-be-bothered-to-find-that-neutral. Almost ironically, most electrical installs are in far better shape AFTER installing a Victron inverter than it was before… cause it forces you to do it right.

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Great post, thank you.

Thanks. Love this tipe of posts.

I would say that my installs comply mostly up to nr12. From nr 13,14 and 15 I would love more detailed info as I see no SANS referance.

DC I have noticed is a very neglected topic in general and I for one was guilty of that as well. Since I started with solar I made an effort to look onto DC and I was surpized on what I was missing all the time.

Will be following this post.

Excuse the ignorance, but what is a TN-S and a TN-C system?

TN = Terra Neutral. It means neutral is tied to an earth spike.

S = Separate. It means the earth arrives from the supplier on a separate conductor. So you have three wires coming from the transformer to your kiosk where it connects to your house (I will assume single phase for simplicity).

C = Combined. It means you get only two wires from the transformer, and the neutral wire also doubles as an earth (it is already earthed at the transformer).

In most installations where earth and neutral is combined, you are expected to install an earth spike on the premises, and earth neutral a second time. From this point on you then run a separate earth conductor. The installation is then known as TN-C-S (combined up to a point, then separate).

When the regulations say you cannot convert TN-S to TN-C, what they really mean is thou shalt run separate earth conductors always and never combine them with a neutral. The last time earth and neutral is allowed to meet is either at the transformer (if it is a TN-S setup), or at the kiosk (if it is a TN-C-S setup).

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