PSW inverter recommendations

[MtB]

46 minutes ago, Loddon said:

Yes I've had one like that, was a while ago had iec input.

Remember boats are a small market.

 

So on your boat, where did you plug your mains-from-12Vdc-producing inverter, into the mains?

[GUMPY]

12 minutes ago, MtB said:

 

So on your boat, where did you plug your mains-from-12Vdc-producing inverter, into the mains?

Are you being deliberately obtuse/thick?

I plugged the 230v shore power into the 230v input of the inverter.

 

Edited October 6, 2022 by Loddon

[Higgs]

On 05/10/2022 at 19:05, jonathanA said:

I really am struggling to understand what you think you have and what you think your GI is doing. 

 

The Gi is only in the earth so this doesn't make sense to me :

"But all the mains supplying equipment pass through the GI and..."

 

And if your inverter and generator are on board they are unlikely to cause galvanic corrosion and you say you have earthed them to Hull using the GI/Hull connection anyway so they arent using the gi (would be pointless)

 

So sorry I'm just a bit confused about your statements that all your "AC supplies go through your GI." 

 

I think what you are actually saying is that only your shoreline connection uses the Gi, but you no longer use that. 

 

Imagine the shoreline plug socket, attached to the boat (mine's internal), that accepts a shoreline plug from a shoreline bollard. It is the only plug-in plug used, by all and every piece of mains producing equipment. As I am not using a shoreline now, it is still the inlet port for every piece of mains feed. They all therefore use what is in place for shoreline mains set up, going through the GI, control box and RCD. I have no automatic sensing switching. and there's only one plug-in. 

 

 

 

 

Edited October 7, 2022 by Higgs

[MtB]

10 hours ago, Loddon said:

Are you being deliberately obtuse/thick?

I plugged the 230v shore power into the 230v input of the inverter.

 

 

 

Ah yes, I wonder if it was that but dismissed it pretty early on as in 45 years of boating I've never found any need to have shore power backup for an inverter. But you obviously do.

 

Thank you for eventually explaining. The term 'blood from a stone' springs to mind. 

 

 

 

[Higgs]

18 hours ago, blackrose said:

I've just found a page from one of Renogy's other inverter manuals which states it is N-E bonded. So I'm not sure why the one you posted the link to wouldn't be? The only thing I can think it's that because it has an AC bypass option the mains supply is already bonded, but I don't see how that's safe once you disconnect the shore power cable?

 

The above example is not a UK 240v example. The small bolt on the outside of the casing on mine is attached to the shell of the boat. The similar fixture on the generator I have would also be attached to the shell of the boat, when in use. Outside, and when not used to feed the mains on the boat, this connection on the generator should be made to a metal stake driven into the ground. This connection on the generator is directly linked to the earth of the 3-pin plug mains outlets on the generator. But these appliances, when feeding the boat mains, are connected to the shell. They seem to run without a problem. 

 

I can see no other way of providing an earth, other than to connect to the shell. 

 

 

Edited October 7, 2022 by Higgs

[GUMPY]

23 minutes ago, MtB said:

 

 

Ah yes, I wonder if it was that but dismissed it pretty early on as in 45 years of boating I've never found any need to have shore power backup for an inverter. But you obviously do.

 

Thank you for eventually explaining. The term 'blood from a stone' springs to mind. 

 

 

 

Sometimes boats are tied up in marinas/moorings and are still being used as accommodation, then it makes more sense (or did before prices went up) to use the supplied facilities rather than depleting the on board battery bank.

[blackrose]

51 minutes ago, Higgs said:

 

The above example is not a UK 240v example. The small bolt on the outside of the casing on mine is attached to the shell of the boat. The similar fixture on the generator I have would also be attached to the shell of the boat, when in use. Outside, and when not used to feed the mains on the boat, this connection on the generator should be made to a metal stake driven into the ground. This connection on the generator is directly linked to the earth of the 3-pin plug mains outlets on the generator. But these appliances, when feeding the boat mains, are connected to the shell. They seem to run without a problem. 

 

I can see no other way of providing an earth, other than to connect to the shell. 

 

 

 

I'm no expert but I'm pretty sure that frame or case earthing on a generator or inverter is an entirely different thing to N-E bonding.

[Higgs]

16 minutes ago, blackrose said:

 

I'm no expert but I'm pretty sure that frame or case earthing on a generator or inverter is an entirely different thing to N-E bonding.

 All I can tell you is, the connector on the generator is directly linked to the earth pin of the 3-pin plug outlets. It is also advised that this connection should be connected to a metal stake, or rod driven into the earth, when being used in the field, so to speak. 

 

 

Edited October 7, 2022 by Higgs

[blackrose]

11 hours ago, Loddon said:

Are you being deliberately obtuse/thick?

I plugged the 230v shore power into the 230v input of the inverter.

 

 

I don't think it's deliberate. 🤣

 

I'm not sure why you were being aggressively expected to provide explanations for features of inverters? I'd have thought it was pretty obvious that an AC bypass is a feature of some inverters, just as it is with some inverter/charger combis. I've never found the need for it either but that's not really the point. Lots of people on boats use that feature on Victron and other combis.

 

6 minutes ago, Higgs said:

 All I can tell you is, the connector on the generator is directly linked the earth pin of the 3-pin plug outlets. It is also advised that this connection should be connected to a metal stake, or rod driven into the earth, when being used in the field, so to speak. 

 

 

Ok, I've never heard of that being done before. 

Edited October 7, 2022 by blackrose

[blackrose]

I ended up ordering this 2200w Sterling PSW inverter for £499 including VAT and delivery from Cactus navigation & communication.

 

https://sterling-power.com/products/pro-power-sb-pure-sine-wave-inverters

 

It's much more expensive than the Renogy unit, however you can't put a price on safety. Unlike cheaper units Sterling make a point of highlighting the earthing arrangement.

 

The Renogy inverters and the cheap ones on Amazon are ok for running one or two appliances, but without N-E bonding they're just not designed to run a full ring mains with breakers.

Edited October 11, 2022 by blackrose

[rusty69]

On 11/10/2022 at 19:41, blackrose said:

I ended up ordering this 2200w Sterling PSW inverter for £499 including VAT and delivery from Cactus navigation & communication.

 

https://sterling-power.com/products/pro-power-sb-pure-sine-wave-inverters

 

It's much more expensive than the Renogy unit, however you can't put a price on safety. Unlike cheaper units Sterling make a point of highlighting the earthing arrangement.

 

The Renogy inverters and the cheap ones on Amazon are ok for running one or two appliances, but without N-E bonding they're just not designed to run a full ring mains with breakers.

I know someone who is just about to install a Renogy inverter. Looking at the info available from Renogy, it seems very unclear whether these things are N-E bonded, or capable of such. It looks like you may have reached the same conclusion, or at least finding conflicting advice.

 

Without doing the @Gibbo test, can anyone who has installed one of these Renogy inverters, with a built in transfer switch, confirm whether their unit is N-E bonded please, and also whether there is an internal relay that functions when connected to an external mains input?

Edited March 29, 2023 by rusty69
Add a bit.

[blackrose]

2 hours ago, rusty69 said:

I know someone who is just about to install a Renogy inverter. Looking at the info available from Renogy, it seems very unclear whether these things are N-E bonded, or capable of such. It looks like you may have reached the same conclusion, or at least finding conflicting advice.

 

Without doing the @Gibbo test, can anyone who has installed one of these Renogy inverters, with a built in transfer switch, confirm whether their unit is N-E bonded please, and also whether there is an internal relay that functions when connected to an external mains input?

 

They're definitely not N-E bonded. I established that much after I bought one and then returned it. Renogy Technical Support also told me that they couldn't be modified to be N-E bonded at the AC output, and as I explained to Nicknorman, unfortunately I'm not technical enough to explain why. You'd need to ask Renogy.

 

It may simply be that if Renogy get an enquiry from a consumer asking whether it's safe to modify their equipment their default answer is always "no". But having been given that answer I wasn't willing to take the risk of ignoring it.

 

As far as I could see, none of the cheap pure sine wave inverters that you find on Amazon are N-E bonded. If it doesn't expressly state that it is N-E bonded then I think it's reasonable (and safer) to assume it isn't.

Edited March 29, 2023 by blackrose

[rusty69]

4 minutes ago, blackrose said:

 

They're definitely not N-E bonded. I established that much after I bought one and then returned it. Renogy Technical Support also told me that they couldn't be modified to be N-E bonded at the AC output, and as I explained to Nicknorman, unfortunately I'm not technical enough to explain why. You'd need to ask Renogy.

 

None of the cheap pure sine wave inverters that you find on Amazon are N-E bonded.

Thanks Mike. Interestingly, the American ones mention they are N-E bonded, which I think you may have mentioned, though they don't appear to have the transfer switch built in.

 

It's a shame some of these inverters have such piss poor instruction manuals.

[MtB]

2 hours ago, rusty69 said:

It's a shame some of these inverters have such piss poor instruction manuals.

 

 

Writing a comprehensive and coherent manual in multiple languages probably takes a lot more time than designing the electronics. Printing each copy of a good quality instruction book probably costs as much as all the components on the board.

 

Hence the shyte documentation with these bargain basement products. Its one of the ways they get the price down so much lower than the well respected mainstream brands.

 

 

[IanD]

13 hours ago, MtB said:

 

Writing a comprehensive and coherent manual in multiple languages probably takes a lot more time than designing the electronics. Printing each copy of a good quality instruction book probably costs as much as all the components on the board.

 

Hence the shyte documentation with these bargain basement products. Its one of the ways they get the price down so much lower than the well respected mainstream brands.

 

 

Having being involved in both electronics design/manufacture/documentation and knowing what electronic components and printing cost, I disagree with your first paragraph.

 

It's not cost as such (compared to the hardware) that's the problem (because it's much lower), it's getting people capable of writing/translating an understandable manual -- but for these products there's also no real incentive to do it, people buy purely on price so there's no payback for spending even a small amount of extra money on documentation.

 

You can save a *lot* more by cutting corners on the design by leaving out safety/protection features, using under-rated components and cooling them inadequately, and using the cheapest possible supplier of low-quality components -- which is exactly what they do to come up with the cheapest possible product.

 

Those are the real reasons -- plus *everything* being done in China including design -- why they're cheaper than mainstream brands, the poor documentation is just a side-effect... 😉