RCDs on PSW INVERTED power? Safety question.

[A J]

Having a conversation with a fellow user, we came across a interesting point.
A lot or all inverters don't have protection at the power point?
How will a RCD go being installed at the high volt end of the inverter before your loads of course?

"Seeming RCDs are for "Grid power" Inverted PSW power is way different? I cannot say on how they would react on Inverted power or when needed to PROTECT? Some better than NONE.. HUMM. "

Thoughts? Thank you.

 

[gnubie]

RCDs work by detecting current flowing in a path that is not between active/line/live and neutral. More often than not inverters do not have their neutral tied to ground so there is no path for current to flow. This means that you could hold onto the line/live/active wire and suffer no ill effects, and the RCD would not trip either.

This is not safe.

It's far easier to ensure that neutral is tied to ground thereby ensuring there will be an alternate return path and building in protection to handle that contingency than it is to ensure that there will never be an alternate return path.

*edit*
Now that I've hung out the washing, you can't just tie an inverter's neutral to ground either. There are plenty of crappy inverters out there that will immediately blow up on power on in this configuration. There are work arounds for them but this results in dangerous voltages appearing between ground and the battery terminals. Inverters like this should be thrown out. They are actually illegal to sell in Australia, but you can import them from China and use them yourself still if you don't like living.

 

[HighTechLab]

Some inverters have GFCI outlets on them - If for any reason there is a neutral to ground bond AFTER this GFCI, then it would cause the GFCI to trip. Many cheap inverters run in a "bipolar" type of configuration, where it goes +60 on live and -60 on neutral then on the other half of the wave goes -60 on live and +60 on neutral. These inverters CANNOT have the neutral bonded as it will likely nuke the inverter. Many times your ground pin is tied to your negative terminal on the DC inputs. I know the cheap ones from Harbor Freight that are Modified Sine Wave operate in this manner but it truly varies from inverter to inverter. Also if you are probing with a scope, you cannot clip your grounded reference lead on neutral or you can end up with a shocking experience

 

[gnubie]

Exactly! (I didn't see your post before editing mine )

 

[A J]

AH HA, I did't think they would help! I did think of it 4 odd years ago, it came up again today and I needed the extra to make my suspicions confirmed.
THANK YOU.

How do these people, sellers get away with selling DEATH TRAPS...

gnubie; One would think the LAW should stop these at the port! GOOD GOD... Makes me sooo ANGRY!

HighTechLab; I have scoped my inverter (4 odd years ago) and that's where I found RCDs to be no help, in this case i was right.

 

[gnubie]

Customs isn't staffed nor technically equipped to examine every inverter and determine if it is a kill-you design. If you think it takes a long time to clear a package now, just imagine what the delays would be if that sort of level inspection was required.

 

[HighTechLab]

That's what UL listing is for, not customs! You won't find one of these death trap inverters with a UL sticker on it.

 

[A J]

gnubie; Yea point taken. Just makes me sooo .

HighTechLab; Another point taken "Underwriters Laboratories" I studied Laboratory Operations long ago, I got to know them well and ISO....

Thank you both you have been most helpful .

 

[gnubie]

That's what UL listing is for, not customs! You won't find one of these death trap inverters with a UL sticker on it.

I wouldn't bet on that. Fake electrical goods coming into Australia often bear the Australia C-tick, European CE mark etc. CE... China Export.

 

[A J]

I wouldn't bet on that. Fake electrical goods coming into Australia often bear the Australia C-tick, European CE mark etc. CE... China Export.

NOW YOU TELL US ... I know.
I have been in that boat, all the ticks and bells started to ring when it blew up.. Pulled it apart and the grounding wire was super thin not soldered or screwed but loosely tied to a shield part i had been holding (240V), I cut sick on them and they still sell it, what dose that tell ya, I wonder how i was't electrocuted.
It's now as a lesson but i find my self buying the counterfeit crap, i go that looks good, yep CE, few other standards, when i get it CRAP! $100's later.
When I get on to them about it your from galaxy 216?? .