Solar challenges

[Isetech]

Doing normal electrical work on sites which have solar installations.

Our standard requirement is copy of all COC's for the site, before we step foot on the site and that people is where the fights normally start.

How do you deal with the non compliant COC's on properties where customers want you to take over the electrical and maintenance on the property ?

Without even looking at the COC, you can already identify a list of visible non compliant issues.

Lets say you have a 5 kw inverter and a 35 or 40 amp supply breaker, the way I see it due to the pass through current using a 2.5 mm 4 core surfix for the input and output would automatically be a code violation.

The same with the 8 kw inverter with a passthrough current of 50 amps, with an anything form a 50-63 amp mcb supplying the inverter input, a 6 mm 4 core surfix just wouldn't cut it. We can go into details about the thin single earth wire another time.

The solar COC is added to the original COC, which is great, but, how do you add a COC to the original if you modify all the DB's to essential and non essential?

If the solar installer modifies every DB on the property, surely the solar COC/test report becomes the original and the original is no longer valid?

If you look at the top of the test report, it clearly states "" Test report for DB/ supply" so if you modify the DB in any way the original test report for that DB is no longer valid?

You would have to carry out a full test report once the DB is upgraded.

[Isetech]

By the way, as we all know, the minute you touch any part of that elctrical, you become liable for everything that is or was wrong with the installation.

It is different if you add a solar system and new Sub DB's which the essential/inverter output is not located in or connected in the main DB.

[Sparks]

Exactly. Nobody looks at what the pass-through current is, let alone make provision for it.

[Isetech]

Electricians cant even tell the difference between a PZ and PH screwdriver or a standard mcb vs a D curve and you expect them to understand passthrough current?

It could explain why green card holders (with a whole 3-5 days worth of training) are the preferred solar installers.

Exactly. Nobody looks at what the pass-through current is, let alone make provision for it.

[GCE]

Exactly. Nobody looks at what the pass-through current is, let alone make provision for it.

I don't quite understand what provision you talk about with regards to pass through current

[Sparks]

I don't quite understand what provision you talk about with regards to pass through current

Using correctly rated breakers and cables instead of underrated breakers and cables would be taking precaution and making provision. I am currently redoing new installations, done by a green card holder brought from COCT to the Eastern Cape by the developer of a new residential complex. The electrical contractor has very limited knowledge of SANS, to the extent that an ECA official has abused his position and made ridiculous demands for changes to the installation which are not dictated by SANS. I have been contracted by the contractor to "rectify" the "faults", but have informed him which items are not in contravention. As long as he keeps paying me, I will do as he asks, albeit unnecessary.

[GCE]

Using correctly rated breakers and cables instead of underrated breakers and cables would be taking precaution and making provision. .

Pass through current is in my opinion not a rating that should be taken into account for normal operation of the inverter .
CB should be rated at the load that is intended to used under normal conditions and the wire size would follow.

What we are seeing is guys installing 5kw inverters along with a 5KWH battery and then all protection is based on the pass through current of a 10kw system.As soon as there is a dip in power/loss of power/loadshedding the inverter and battery are trying to pick up the pass through current and you end up with a low DC voltage fault which indicates that the actual inverter was overloaded

We are also seeing all socket outlets and light circuits in a domestic dwelling running off the inverter and the kitchen has a dishwasher , wash machine, kettle , dishwasher etc and the worst is when they include the geyser and stove.

Owners are then told to make sure that they don't use to many appliances at the same time which in my opinion contravenes Clause 7.12.2.4

The battery warranty is gone because the warranty terms state that on average the battery should only discharge at 0.5c even though spec says 1c and more than 3 overloads voids warranty

An inverter is a generator not an appliance - We would never load a generator at 100% load and expect it to last .

Then we also have clause 5.5.2 and 5.3.1 with reference to Annex c which stipulates sizing of power requirements for socket outlets



SANS 10142-1 ed3.1
7.12.2.4 Where the alternative supply is intended to provide a supply to an
installation that is not connected to the main supply, or to provide a supply as
a switched alternative to the main supply, the capacity and operating
characteristics of the alternative supply shall be such that danger or damage
to equipment does not arise after the connection or disconnection of any
intended load as a result of the deviation of the voltage or frequency from the
standard range. Means shall be provided to automatically disconnect such
parts of the installation, as may be necessary if the capacity of the alternative
supply is exceeded

5.5.2 Harmful effects by electrical equipment
Electrical equipment shall be so designed and arranged that any damage as
a result of a fault be localized as much as possible. The equipment shall not
have harmful effects on other equipment or on the power supply during normal
service (including switching operations). Factors that can lead to harmful
effects include
a) the power factor,
b) inrush current,
c) asymmetrical load, and
d) harmonics

5.3.1 Estimated load
The load of an installation shall be estimated to determine the type and
capacity of the required electricity supply.
NOTE 1 Annex C gives an example of estimating the load for residential installations
but the method is not to be regarded as an exact method.
NOTE 2 The supplier may have special requirements for large installations and for
installations that need special consideration.

[GCE]

to the extent that an ECA official has abused his position and made ridiculous demands for changes to the installation which are not dictated by SANS. I have been contracted by the contractor to "rectify" the "faults", but have informed him which items are not in contravention. .

Would be interested to know what the demands where made and what you deem not be in contravention

[GCE]

The electrical contractor has very limited knowledge of SANS, to the extent that an ECA official has abused his position and made ridiculous demands for changes to the installation which are not dictated by SANS. I have been contracted by the contractor to "rectify" the "faults", but have informed him which items are not in contravention. As long as he keeps paying me, I will do as he asks, albeit unnecessary.

I agree with that statement that there is limited knowledge - I am not aware of any ECA representative going to the complex
I as a contractor was asked by a client to have a look at his installation as there where strange things happening and his electricity bill seemed excessive when he took into account the PV system installed and that the geyser was on a Kwikhot PV system.
I was shocked at what was discovered by my IE's - As stated , it was visual as we did not want to disturb or alter the installation in any form.

The contractor has taken responsibility and repairing the problems . He was quick to put his hand up and say that " I buggered up and need to fix up " . Once the news got out we were asked to inspect further units on the owners insistent even though we keep stating that the contractor is rectify his errors in all units

We are being asked to go back and check that they have been rectified and brought up to SANS 10142-1 and SANS 60364-7-712
As a workshop we are well versed on the regulations and are not often wrong in our interpretation of the regulations

[Isetech]

What do you do if the meter box is closer to the outbuilding DB than the main DB ?

1/ Double up the cable in the meter circuit breaker and run the same size cable cable directly to the outbuilding DB, or

2/ Fit a sub Db next to the meter, label it main DB, fit a main switch and 2 circuit breakers (both 60 amp because the cables are both 16 mm sq) one feeding the main DB (which now becomes a sub DB 1) and the other to the outbuilding (which will be labelled Sub DB 2)