Inverter earth or not?

[nabsim]

I knew floating system was in there somewhere but couldn’t remember the ins and outs lol. I also knew double insulated was important. I did research all this before deciding not to connect earth on my inverter as apart from a 300W inverter I used to use they are something fairly recent to me.

Earth spike coming into it is obvious if you ever use generators as they tell you to use one.

 

[merl]

I knew floating system was in there somewhere but couldn’t remember the ins and outs lol. I also knew double insulated was important. I did research all this before deciding not to connect earth on my inverter as apart from a 300W inverter I used to use they are something fairly recent to me.

Earth spike coming into it is obvious if you ever use generators as they tell you to use one.

That's correct Neil, the output from the generator winding is usually centre tapped. So rather than grounding one end the centre tap is grounded, this effectively leaves you with 2 lives but at 1/2 potential so 110V -0-110v . Site generators are 110v with a centre tap so they are 55-0-55 so the max belt you can get from live to earth is just 55v and virtually impossible to get electrocuted with that.

 

[nabsim]

That's correct Neil, the output from the generator winding is usually centre tapped. So rather than grounding one end the centre tap is grounded, this effectively leaves you with 2 lives but at 1/2 potential so 110V -0-110v . Site generators are 110v with a centre tap so they are 55-0-55 so the max belt you can get from live to earth is just 55v and virtually impossible to get electrocuted with that.

I have never earthed a genny either Merl. We used to get some huge diesel genny sat the quarry if we ever had power problems on a section and they were never earthed either. They were 3 phase jobs though I think or is that not possible? Never really had anything to do with them except ordering them in when needed and making sure folks were checking/filling with red

 

[merl]

It's over 40 years since I worked on site Neil and they were never earthed back then either! Knowing how Elf un Safety conscious they are on site nowadays I bet checking site electrics is a full time responsibility for at least 10 men and another 10 men to check on the first 10!

 

[alwaysared]

This from my Victron Manual:


Regards,
Del

 

[nabsim]

This from my Victron Manual:

View attachment 73804
Regards,
Del

Those multi plus are a different beast to my stand alone inverter Del. They do the incoming mains as well and can split output between inverter and mains I think.

Never said what I do is the right way though, just how I do it. I am aware of double insulated appliances.

I best not mention at one time I used a suicide lead

 

[alwaysared]

Those multi plus are a different beast to my stand alone inverter Del. They do the incoming mains as well and can split output between inverter and mains I think.

Never said what I do is the right way though, just how I do it. I am aware of double insulated appliances.

I best not mention at one time I used a suicide lead

Yes they do split the incoming mains, one connection is to run something only when the EHU is connected and not when the inverter is turned on for example a three way fridge or a water heater

Regards,
Del

 

[nabsim]

Yes they do split the incoming mains, one connection is to run something only when the EHU is connected and not when the inverter is turned on for example a three way fridge or a water heater

Regards,
Del

Can’t you share the load between the inverter and mains when on EHU as well Del? Seem to recall that could be a plus point on low amp sites if you have sufficient battery, may be wrong though lol.

Don’t know if that Renogy combined charger/inverter does the same sort of thing or not.

 

[alwaysared]

Can’t you share the load between the inverter and mains when on EHU as well Del? Seem to recall that could be a plus point on low amp sites if you have sufficient battery, may be wrong though lol.

Don’t know if that Renogy combined charger/inverter does the same sort of thing or not.

Yes you can use it to assist a low amp ehu so it can be used as a 16amp circuit. You can also use it in charger only mode. Expensive but it's a good piece of kit.

Regards,
Del

 

[wildebus]

Yes you can use it to assist a low amp ehu so it can be used as a 16amp circuit. You can also use it in charger only mode. Expensive but it's a good piece of kit.

Regards,
Del

Yup, this is a key benefit of the Victron Multiplus where you can use the inverter to make up the extra power that the EHU cannot deliver. Allows you to use your regular devices without tripping the site breaker - Called "Power Assist". Really handy.
I don't know if other Inverter/Chargers makes have this kind of feature?

A standard Inverter with a Mains input will not have that feature. That will be a straight Transfer Switch that will send EHU if available to the output of the device or Inverter power if no EHU, but not a mix of the two.