Installing a Sunsynk inverter

[Dave A]

I would have thought there would be vents at the top on the unit, heat rises, but maybe that was taken into to consideration while designing the covers.

You don't want vents at the top as this would be an easy route for dust and small objects to fall into the unit.

[GCE]

Then we need a solar calculator. I see there calculators, if we get more than 10 installs (6 so far, 4 to go) , then I will get a paid version.

https://www.helioscope.com/

If you know of any good free calculators, let us know.

Try this one - Works well and allows you to customize settings to suit

https://www.opensolar.com/

[GCE]

Note that the PV frame earth, and DB electrical earth must not be connected. Each must have it's own earth path. The PV frame earth should be the shortest path to earth, and to the earth spike with a minimum of 6mm copper wire. This is to protect the system from a lightning strike on the roof or frame. You want to guide the electrical energy strike to earth, not to the house electrical earth. The earth on the inverter and electrical system is for the safety of the user in the case of a Live fault, in which the ELU will then disconnect the supply from the load/fault.

I have to disagree with your statement
The PV panels and frame work is part of the electrical installation and needs to be earthed through the normal wiring back to the inverter and D/Board.

The PV panels and frame work cannot be part of a Lightening protection design - The lightening protection design and install would be a separate earth using the shortest route along with lightening rods effectively above the panels to keep the panels out of a lightening zone.

I would regard the PV panels etc similar to say Stadium lighting - You would earth the light fittings as per normal SANS but then install a separate lightening protection rod above the light fittings with a earth conductor directly into the ground below the mast.

Pasted from SANS what I feel is relevant

7.12.7 Additional requirements for photovoltaic (PV) and similar
installations that provide a supply as an alternative to the main supply
7.12.7.6 If applicable, all exposed conductive parts may require earthing as
prescribed in 6.12.3.

6.12.3 Earthing of exposed conductive parts
6.12.3.1 The following conductive parts shall be earthed:
a) all exposed conductive parts of an installation other than those described
in 6.12.3.2;
NOTE Metal enclosures on PVC conduit should be earthed if they can become live
and can be touched.
b) all conductive cable sheaths and armouring, wireways and catenary wires;
c) the earthing terminal of a socket-outlet;
d) the secondary winding of a transformer if it is not a safety transformer;
e) earthing terminals of all permanently connected electrical equipment and
appliances;
f) conductive parts of discharge luminaires and equipment that need special
earthing arrangements; and
g) all class I equipment.

6.12.3.3 Metallic frames and metallic enclosures of electrical equipment shall
be made electrically continuous.

[Isetech]

You don't want vents at the top as this would be an easy route for dust and small objects to fall into the unit.

Have you looked at the dust cover on the side of your inverter I keep telling people, please clean your dust cover on the fan, top or side they still collect dust.

[Justloadit]

I have to disagree with your statement
The PV panels and frame work is part of the electrical installation and needs to be earthed through the normal wiring back to the inverter and D/Board.

The PV panels and frame work cannot be part of a Lightening protection design - The lightening protection design and install would be a separate earth using the shortest route along with lightening rods effectively above the panels to keep the panels out of a lightening zone.

I would regard the PV panels etc similar to say Stadium lighting - You would earth the light fittings as per normal SANS but then install a separate lightening protection rod above the light fittings with a earth conductor directly into the ground below the mast.

Pasted from SANS what I feel is relevant

7.12.7 Additional requirements for photovoltaic (PV) and similar
installations that provide a supply as an alternative to the main supply
7.12.7.6 If applicable, all exposed conductive parts may require earthing as
prescribed in 6.12.3.

6.12.3 Earthing of exposed conductive parts
6.12.3.1 The following conductive parts shall be earthed:
a) all exposed conductive parts of an installation other than those described
in 6.12.3.2;
NOTE Metal enclosures on PVC conduit should be earthed if they can become live
and can be touched.
b) all conductive cable sheaths and armouring, wireways and catenary wires;
c) the earthing terminal of a socket-outlet;
d) the secondary winding of a transformer if it is not a safety transformer;
e) earthing terminals of all permanently connected electrical equipment and
appliances;
f) conductive parts of discharge luminaires and equipment that need special
earthing arrangements; and
g) all class I equipment.

6.12.3.3 Metallic frames and metallic enclosures of electrical equipment shall
be made electrically continuous.

Note what you have mentioned, however if you look at the construction of a PV panel, there is no way, even a catastrophic failure of the cells that the electrical part of the PV circuit will ever come into contact with the frame, as the cells are encased in a glass and plastic film which is then glued into the frame. It is like saying that you need to connect each window frame in a house to your electrical earth.

I agree that adding lightning rods improves lightning protection, however in the majority of cases, the PV frames are below the highest point of the roof, and the earthing that I stated earlier, would be to dissipate any excess energy in the area during the lightning strike.

Yes an installer could tie the PV cable to the frame, and some mechanical issue could cause the failure of the PV cable sheath, and the inner metallic cable then could be exposed and shorted to the frame and create an issue.

all exposed conductive parts may require earthing as
prescribed in 6.12.3. A PV panel by design has no exposed conductive paths unless some one cuts the premade cables and moulded connectors

[MPAD]

Is this type of issue a concern?

[Isetech]

What we have learnt from lightning experiences, no matter what you install, if any part of your installtion is hit by lightning, chances are good that you will be replacing a lot of the components. So best you just make sure that whatever you install is insurance approved, thats all that counts at the end of the day. I read the policiy carefully then decide what route to take with regards to lightning/surge protection.

A word of advice, we got a letter from our insurance recently, to notify us that we are no longer covered for surge related damages, only lightning, if you going to claim, make sure you read your policy and verify that there was lightning on the day, trust me the last claim I dealt with, only a small portion of the claim was paid, the broker actually took out his phone checked the date of the claim and pointed out to me that there was no storm on the day.

Is this type of issue a concern?

[Isetech]

With the little experience we have installing inverters, generally we seem to be geting it right, however on some of the sites where I have advised customers to stick to the plan, they have indicated they are happy to do it their way.

One of the sites where the customers requested that we dont split the essential and non essential and as expected we got the call for a F54 fault.

Another issue we have experienced, with a load that has been split into essential and non essential, we had an F14 fault during load shedding. The lesson to learn from this, if you install a inductive load (no matter how small) on the essential side of the DB, make sure you allow for the startup current or make sure that the inductive load is connected to a VSD or some form of soft start. Examples of this, aircons, booster pumps for water storage, etc

[Isetech]

How we have grown since the start of this thread.

Was busy searching safe isolation procedure and this popped up.