ianm

It has been sold

Item: Crimping Tool - Hydraulic 16-240mm sq Age: 10 months Price: R750 Payment Method Accepted: Cash/EFT Warranty: None Packaging: In original carrying case Condition: As new Location: Woodmead, Sandton Reason: Selling Up Shipping: For buyer's cost and risk Collection: Preferred Link:

For a bit more you could maybe consider an installation like this: 5 kW VMIII + Hubble AM-2 It is a nicely matched system as the AM-2 is 5.5 kWh (1C), so the inverter is able to supply the full 5kW (more than enough to boil the kettle).

Hi Rian I use the DB earth for the earth bond contactor. If I were to use a separate earth spike, it would just be near to the existing one, so there is no point. Regards Ian

Hi @MyOwnPower I have installed (almost) exactly as indicated in my last diagram. All working perfectly since April. The only change was to install a double pole mcb on the main input instead of the single pole. Not strictly necessary, but I preferred it that way. If the inverter does not have an automatic earth neutral bond, then the earth neutral relay is an absolute requirement. Without this, in the absence of grid power, the neutral can float at more than a hundred volts, a dangerous situation. I used a 250V contactor for the earth neutral bridge, located in the inverter sub-db. My recommendation is to keep the neutrals separate as per my diagram. Regards Ian

I also have been running a 5kW Sunsynk off a single US3000C limiting charge/discharge to 37A with no issues. I also plan to install a second US3000C in the future. It has been mentioned that Pylontech require more than one battery to be connected to the inverter for the warranty to be valid. I have not seen this in any official Pylontech documentation, specifically it it not mentioned in their installation manual or their warranty documents. Personally, I am not convinced by the one reseller that I have seen who claims this. Having said that however I would also recommend the Hubble AM-2, it will give you more capacity, a higher C rating, and is way easier to install. Not sure what inverter you are planning, but a single AM-2 is nice match for a 5kW inverter. Try and push the budget a bit.

Better explanation here: https://www.sunsynk.org/post/basic-understanding-of-the-sunsynk-inverter Jump to the 14:53 position.

Keith Gough covers this in this video at the 40 second point: There is another video where he talks more about this and the reason, I will try and find it.

I guess the reason for the mcb immediately in front of the spd is the difference in trip values between the mcb on the input/output of the inverter (in my case 35A) and the recommended mcb in front of the spd (in my case 25A), to prevent catastrophic destruction (fire) of the spd. These values however may be close enough in my case not to be relevant. Additionally the mcb's on the input and output of the inverter only trip on an overcurrent on the live line. An overcurrent on the neutral line won't be detected. This will not be of concern on the output of the inverter where the neutral earth bond is in close proximity, but on the input line, the neutral earth bond could be 500m away and on a different earth point, more than enough for lightning to induce a damaging spike. https://www.lsp-international.com/why-install-a-scb-surge-circuit-breaker-in-front-end-of-spd-surge-protective-device/ https://www.ecmweb.com/power-quality-reliability/article/20886952/the-basics-of-using-circuit-breakers-with-surge-protectors I am not sure of any South African regulations concerning the use of circuit breakers immediately before an spd, but I do know that the UK regulations specifically require such a device if the spd does not have one built in. All of the literature I have read shows the spd mcb to be immediately before the spd, not on the earth line as shown in the Sunsynk documentation. I can only surmise this is because they want to maintain a level of protection if only one line of the spd gets damaged by a spike. Thanks for the all the input, I have done a lot of reading up on the matter, but still have not been convinced either way. However given the low cost of mcb's relative to the equipment, I might just go with the configuration I posted above. @Vassen, I didn't include a main switch between the changeover and essential loads rcd as the SPT240 has a centre off position. I am not sure if this is sufficient.

Okay, thanks, so then the circuit would be:

So the only way to avoid rcd 1 tripping is to wire it such that the inverter is not protected by an rcd. Is that legal?

Thanks, how did you resolve this?

Many thanks for the reply. 1) Good point. 2) One of the things I was unsure about. The spd data sheets indicate the requirement for a fuse or mcb on each input line (if the spd doesn't have this built in). The Sunsynk manual shows one mcb on the earth line of the spd, in addition to the 35A mcb on the inverter output. I have not seen this configuration (the mcb on the earth line) anywhere else. 3) Yes, the 32A mcb's should be 35A 4) Sunsynk recommend spd's on both sides (I think, I could be misinterpreting this).

Hi everyone I have a 5kW Sunsynk inverter which I would like to use as a loadshedding backup. I may install pv's later. Please could the experts here take a look at my proposed wiring and advise accordingly, particularly in regard to legal compliance and Sunsynk recommended practice. Thanks. wiring diagram ver1.pdf