Kalahari Cruiser Posted May 3, 2023 Share Posted May 3, 2023 For my 8KW SunSynk (un-commissioned), I need to create that N-E bridge for when the inverter is in islanding mode. Unfortunately I am still uncertain on some aspects and hope others will be able to advise. I've also seen two of Keith's N-E videos, i.e. the two below: I had initially hoped to install the contactor inside the AC protection box but it doesn't fit - it's DIN mounted but way too deep so will require another box unfortunately. I was advised to get a 3-phase / 415V contactor (I had wanted a 45A unit). I see Keith in the first video above also uses one of these but only uses "one of the phases" if I heard correctly. In other words: Can I use my 415V contactor (pictures below) that I have, but using it for 230V purposes / single phase inverter install? (House is single phase). Keith temporarily mounts it inside the inverter but mentions it should obviously go in its own separate housing. In terms of sizing: I found reference in the SunSynk manual that a 40A should be used for the 8.8KW inverter. I've also seen other references that a much smaller unit is fine. Since I have this one already, is it fit for purpose? Lastly, in the bottom video, at around 2:00, Keith talks about a contactor which is normally closed (NC), and says that it must be N/C and not N/O. Mine is N/O, is this correct? Are the 3.6KW and 8.8KW inverters different in this regard? I understood that the bond must be created only when energised by the ATS240 output, and otherwise be open to avoid dual N/E bonds. Is this understanding correct? For planning/mounting purposes (placing of conduiting etc.), are the wired connections only between the inverter and contactor, rather than also with the rest of the AC box items? (COS, breakers etc...). Many thanks in advance! Quote Link to comment Share on other sites More sharing options...
Steve87 Posted May 3, 2023 Share Posted May 3, 2023 Yes you can use a 415V Contactor for single phase use. The reason why is that you can get a single segment to bond the Neutral & Earth. What's the importance is the bond happening. This is what will cause your Earth Leakage to function correctly. A Contactor is overkill for this application but to overcook something is not a bad thing in this case. Kalahari Cruiser 1 Quote Link to comment Share on other sites More sharing options...
Kalahari Cruiser Posted May 3, 2023 Author Share Posted May 3, 2023 Great, that's comforting @Steve87 many thanks for this. I was under the impression that I need a 40A contactor and got this - having been unable to find a 230V smaller unit (only in 25A). Cost of the contactor was around R500 odd so no trainsmash, but slightly annoyed by the size and now needing its own separate box... N/O being correct too? Quote Link to comment Share on other sites More sharing options...
TaliaB Posted May 3, 2023 Share Posted May 3, 2023 42 minutes ago, Kalahari Cruiser said: Great, that's comforting @Steve87 many thanks for this. I was under the impression that I need a 40A contactor and got this - having been unable to find a 230V smaller unit (only in 25A). Cost of the contactor was around R500 odd so no trainsmash, but slightly annoyed by the size and now needing its own separate box... N/O being correct too? @Kalahari CruiserThe contactor is fine just ensure the coil voltage is 230v not 380v the ATS 240 output is 230v AC, on the box it states that the coil voltage is 415v ac it will not energize via the ATS 240 output. Steve87 and Kalahari Cruiser 2 Quote Link to comment Share on other sites More sharing options...
Steve87 Posted May 3, 2023 Share Posted May 3, 2023 Yep always make sure the coil is appropriately rated for 230V on the ATS 240. I also make use of the contactors but I Install the entire family of these inverters & the 12kW & some 16kW hardware does not have the ATS240 installed. So now you have a NO contactor that is useless. That is why I have reverted to a 230V Relay. Because it has a coil & allows NO & NC. That's a one size fits all solution. & It it's din mount & very discreet. TaliaB and Kalahari Cruiser 1 1 Quote Link to comment Share on other sites More sharing options...
Kalahari Cruiser Posted May 4, 2023 Author Share Posted May 4, 2023 9 hours ago, TaliaB said: it will not energize via the ATS 240 output Ah right, thanks @TaliaB. I guess that makes sense - supplier insisted I should get this one and at the time I wasn't sure about the coil rating issue. Ideally I want to get a relay as per Steve, that looks very neat on his installs and fits nicely in the AC box - I'd have space for that. Anyone know where I can get a Finder or similar relay at short notice? What relay amp rating is required for a 8.8KW SunSynk? @Steve87 Does the 12KW three- phase not have an 'equivalent' ATS240 output installed? (I'm thinking of passing this relay on to a family member who's about to install a 12KW 3-phase inverter) Quote Link to comment Share on other sites More sharing options...
TaliaB Posted May 4, 2023 Share Posted May 4, 2023 27 minutes ago, Kalahari Cruiser said: What relay amp rating is required for a 8.8KW SunSynk? I am situated in Gauteng and get all my switchgear from Voltex but you can try ACDC or any electrical outlet close to you they are actually very common ask for din rail mounted relay. The ratings are normally 10 amp or 20 amp DPDT( double pole double throw) contacts. You can use this relay for all variants of inverters the amp rating is not subject to inverter size as it is bonding neutral to earth on inverter output side. Kalahari Cruiser 1 Quote Link to comment Share on other sites More sharing options...
TaliaB Posted May 4, 2023 Share Posted May 4, 2023 @Kalahari Cruisernot sure where you situated as i have some relays with me and could help you out but according to your handle it sounds you are in the Northern Cape Kalahari Cruiser 1 Quote Link to comment Share on other sites More sharing options...
Kalahari Cruiser Posted May 4, 2023 Author Share Posted May 4, 2023 Thanks very much. This contactor I got did come from ACDC and they were very helpful - except that they advised that I get that particular contactor for my single phase inverter. But that's very helpful to know regarding the relay - that a 10 or 20amp relay will be sufficient - I wasn't sure about this. I'll see whether they're prepared to take the boxed contactor back for credit and to get a relay with base there. I suppose they can be set as NO or NC or is there something specific that I need to mention? Thanks again for advice. 1 minute ago, TaliaB said: Northern Cape Nope, in the Far South / Cape Town. Many thanks - I'll try pop in at ACDC Paarden Eiland tomorrow. Thanks very much for the offer. Quote Link to comment Share on other sites More sharing options...
TaliaB Posted May 4, 2023 Share Posted May 4, 2023 44 minutes ago, Kalahari Cruiser said: Thanks very much. This contactor I got did come from ACDC and they were very helpful - except that they advised that I get that particular contactor for my single phase inverter. But that's very helpful to know regarding the relay - that a 10 or 20amp relay will be sufficient - I wasn't sure about this. I'll see whether they're prepared to take the boxed contactor back for credit and to get a relay with base there. I suppose they can be set as NO or NC or is there something specific that I need to mention? Thanks again for advice. Nope, in the Far South / Cape Town. Many thanks - I'll try pop in at ACDC Paarden Eiland tomorrow. Thanks very much for the offer. Yes you use the NO contact as soon as the inverter goes into island mode there is power at the ATS 240 that in turn enegizes the relay creating your earth neutral bond Quote Link to comment Share on other sites More sharing options...
Kalahari Cruiser Posted May 4, 2023 Author Share Posted May 4, 2023 Thanks TaliaB - yes that confirms my understanding, just wasn't sure whether relays also have NO/NC in a similar way that a contactor has. I'll try find a relay asap. Thanks for your assistance! TaliaB 1 Quote Link to comment Share on other sites More sharing options...
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