This old topic - asked this in my solar thread  but it may be more relevant to the electrical forum. Just saw last week how a family member's backup power installation (Sunsynk / Hubble batteries) seemed to miss the NE bond when in islanding mode - electrician apparently came back to sort this yesterday. 

Please could I get assistance with the hardware / components required for this - for my upcoming install. I would like to be informed and have these components on standby for the installer, and be able to test this afterwards. 

If I understand correctly, the NE bond on the inverter AC DB side can be achieved in various ways, eg through a relay or a contactor switch - which are linked to the ATS240 output of the SunSynk 8KW inverter (one can also get one of those SegenSolar standalone enclosures, which I don't plan to do). 

 

(a) CONTACTOR option (specs 230V / 2NO / 25A?) - example link as confirmed earlier in my other thread by @Kalahari Meerkat - otherwise if sourced elsewhere what are the minimum required specs (Amps, 1xNO?, 1 pole?). I've looked on the Voltex site too and those all seem to be 3-pole (I guess one can just use one?). Any link to one (example)? Especially interested to know whether should be NO and what the AH rating should be.

or

(b) RELAY option (230V, but what specs? Amps and number of contacts?) Could someone post a link to a suitable one? Example (but no stock). read somewhere that a 10A relay is enough. Any links to a suitable one? Is the relay installed at the inverter or in the AC DB box?

 

I assume contactor is the better option, can handle more current, or is this moot in this scenario?

In terms of installation, I assume there needs to be a connection from the ATS240 on the inverter to this relay or contactor, that is NO when there's grid available, and closed (bonded) when grid is off. And I'm unclear on this - the relay or contactor in turn is also connected to the load side to neutral and earth (in the AC DB box), and closes instantly when grid is absent through a signal sent by the ATS240 output?

🙏 🙏

This is what I have.
Simple relay with an indicator lamp.

 

Edited March 2, 20233 yr by WannabeSolarSparky
updated image

Thank you WS. Is that a 10A CB alongside a 25A NO Contactor? Sitting inside the AC protection box? 

48 minutes ago, Kalahari Cruiser said:

I assume contactor is the better option, can handle more current, or is this moot in this scenario?

This would do the trick and the spare contact pair could be used to trigger an alarm or turn on a light to indicate absence of E-Skom...

@WannabeSolarSparky with the CB allowing the E-N bond to be undone... not sure that's the wisest move... his CB would always have to be switched on, for the E-N bond to be able to function and be controlled by the inverter...

7 minutes ago, Kalahari Meerkat said:

CB would always have to be switched on, for the E-N bond to be able to function and be controlled by the inverter

Yeah that diagram is outdated, the CB is supposed to only be for the indicator light and it was changed to a 5amp CB, my electrician changed that when he did the CoC

12 minutes ago, Kalahari Meerkat said:

This would do the trick and the spare contact pair could be used to trigger an alarm or turn on a light to indicate absence of E-Skom...

Thanks very much @Kalahari Meerkat. That contactor in your link seems to have 2 NO contacts (and 20A - is that sufficient?) and yes, absence of grid light will be essential. Could a "duplicate" wire also be run from there to inside the house to also have such an indicator light added to the Main household DB (which in my case sits in the kitchen and is readily viewable)? 

Is there a need for a CB just for the indicator light, or can it be a direct connection from contactor to indicator light(s)? 

Edited March 2, 20233 yr by Kalahari Cruiser

1 hour ago, Kalahari Cruiser said:

 

This old topic - asked this in my solar thread  but it may be more relevant to the electrical forum. Just saw last week how a family member's backup power installation (Sunsynk / Hubble batteries) seemed to miss the NE bond when in islanding mode - electrician apparently came back to sort this yesterday. 

Please could I get assistance with the hardware / components required for this - for my upcoming install. I would like to be informed and have these components on standby for the installer, and be able to test this afterwards. 

If I understand correctly, the NE bond on the inverter AC DB side can be achieved in various ways, eg through a relay or a contactor switch - which are linked to the ATS240 output of the SunSynk 8KW inverter (one can also get one of those SegenSolar standalone enclosures, which I don't plan to do). 

 

(a) CONTACTOR option (specs 230V / 2NO / 25A?) - example link as confirmed earlier in my other thread by @Kalahari Meerkat - otherwise if sourced elsewhere what are the minimum required specs (Amps, 1xNO?, 1 pole?). I've looked on the Voltex site too and those all seem to be 3-pole (I guess one can just use one?). Any link to one (example)? Especially interested to know whether should be NO and what the AH rating should be.

or

(b) RELAY option (230V, but what specs? Amps and number of contacts?) Could someone post a link to a suitable one? Example (but no stock). read somewhere that a 10A relay is enough. Any links to a suitable one? Is the relay installed at the inverter or in the AC DB box?

 

I assume contactor is the better option, can handle more current, or is this moot in this scenario?

In terms of installation, I assume there needs to be a connection from the ATS240 on the inverter to this relay or contactor, that is NO when there's grid available, and closed (bonded) when grid is off. And I'm unclear on this - the relay or contactor in turn is also connected to the load side to neutral and earth (in the AC DB box), and closes instantly when grid is absent through a signal sent by the ATS240 output?

🙏 🙏

Use a normal 3 pole 220v coil contactor 40amp with aux contact for indicator. Always safer to use a contactor should their be a  neutral earth fault. Below type this one from Takelot but you could source from Voltex.

https://www.takealot.com/ac-contactor-40a-cjx23210-220v-50hz-rated-coil-voltage/PLID59117485?gclid=CjwKCAiAr4GgBhBFEiwAgwORrdGvLAg_guluw_FDYio47DMGdXtnfU8R6-CZc2WZUpzfblseKLwWqhoC9lEQAvD_BwE&gclsrc=aw.ds

Thanks very much @TaliaB much appreciated too. 

Would this from Voltex be the equivalent? It's quite a bit more costly than the TA link (or the other options mentioned). 

https://www.voltex.co.za/product/schneider-tvs-easypack-contactor-40a-18-8kw-240v-lc1e40u5/

Those specs are 40A 3 pole and 3NO - with 3NO contacts I guess both "spares" could each engage a grid failure indicator light (as opposed to doubling up on one spare NO contact). Or is this overkill? 

I was also looking at this option from Hager:

https://www.em.co.za/ESC225

25A, 2NO....

Edited March 2, 20233 yr by Kalahari Cruiser
Added EM Hager link

57 minutes ago, Kalahari Cruiser said:

Thank you WS. Is that a 10A CB alongside a 25A NO Contactor? Sitting inside the AC protection box? 

Original one was before the electrician fixed it.
Updated the correct image.

20 minutes ago, Kalahari Cruiser said:

Is there a need for a CB just for the indicator light, or can it be a direct connection from contactor to indicator light(s)? 

That would depend on the electrician who does the C.o.C and the interpretation of relevant codes.
The extra R35 for the CB should not be a deal breaker

Just now, WannabeSolarSparky said:

The extra R35 for the CB should not be a deal breaker

Indeed - was thinking mainly from the perspective of running out of slots on the board - or making sure that the board is large enough to take them all (e.g. 8-way board vs 10-way). 

https://www.em.co.za/ESC225

That should work. I would just double up on the contacts so that you use both normally open contacts. That gives you 50Amp

Thanks @Jacques Ester. Doubling up - would you mind explaining this a bit more? Would that involve using both NO contacts in a parallel way to link to the (neutral / earth?) in the DB? Would I then lose the option of pilot lights or can they still use one of the double-up'd NO contacts? (Sorry if my language is not clear). 

1 minute ago, Kalahari Cruiser said:

Indeed - was thinking mainly from the perspective of running out of slots on the board - or making sure that the board is large enough to take them all (e.g. 8-way board vs 10-way). 

Yeah that needs to be considered, I have all my inverter connections peripherals bond all in a 20 way db which is pretty much filled up all slots.

34 minutes ago, Kalahari Cruiser said:

Is there a need for a CB just for the indicator light, or can it be a direct connection from contactor to indicator light(s)? 

I would say no, but usually a CB is there to protect the wiring, in case the end device goes short circuit and presumably is a requirement...

36 minutes ago, Kalahari Cruiser said:

and 20A - is that sufficient?

more than, theoretically if you see more than 30 or 40mA between the earth and neutral bond, your GFI/EL switch should see this amount of unbalance between your Live and Neutral and thus trip and disconnect the output of the inverter from whatever is causing the energy flow in the earth-neutral bond...

 

Thanks very much @WannabeSolarSparky

Is that earth neutral contactor in its own housing or does it form part of the AC box? 

 

10 minutes ago, Kalahari Meerkat said:

but usually a CB is there to protect the wiring

@Kalahari Meerkat Many thanks as always. Available slots need to be considered for the AC DB, and as mentioned earlier, it's such an inexpensive addition so may as well have that done too. 

Edited March 2, 20233 yr by Kalahari Cruiser

46 minutes ago, Kalahari Cruiser said:

Thanks @Jacques Ester. Doubling up - would you mind explaining this a bit more? Would that involve using both NO contacts in a parallel way to link to the (neutral / earth?) in the DB? Would I then lose the option of pilot lights or can they still use one of the double-up'd NO contacts? (Sorry if my language is not clear). 

Yes "Would that involve using both NO contacts in a parallel way to link to the (neutral / earth?)"