Automatic EPS versus Manual

[Bob Smith]

Hi

I was under the impression that one of the advantage of having batteries as part of the PV system is to be able to have what is called a backup or Emergency Power Supply. That's when there is a power cut the batteries will continue to deliver power to the house (under certain condition as the power from the batteries is limited blabla).

The reason of this post is to understand in the UK what the regulation is.

I thought that EPS would switch on automatically when there is a power cut. However I have been told recently by an installer that in the UK it is illegal to have an automatic EPS and it has to be manual.

Can someone confirm with source of information please? if I have to go back to the installer I want to make I am right


From here it would seem it is possible to have an automated EPS in the UK

https://uk.smartenergy.co/blog/eps-solar-system/

 

[johnb2713]

If it's illegal then I'm breaking the law. I have an automatic changeover switch, in the event of power loss the contactor disconnects the incoming L & N and connects my consumer units to the EPS's. The contactors have both mechanical and electrical interlocks and are break before make connections. I installed this years ago to provide a quick connection to a generator in the event of a power cut, better than the widow maker lead previously used LOL.

I will be interested to hear what the legal experts have to say ref this.

 

[binky]

every hospital in the country is illegal then! Automatic EPS switching has been around for many years, for premises with diesel generator back-up.

 

[Bob Smith]

every hospital in the country is illegal then! Automatic EPS switching has been around for many years, for premises with diesel generator back-up.

Thanks @johnb2713 and @binky

I am only repeating what the installer has told me.
Now it could be find for commercial, hospital etc.. but not for residential.

However, as I know nothing about this, I thought I looked around and also ask my favorite forum.
When I know more I'll post it here, but if somebody knows, please share. THank you

 

[johnb2713]

Thanks @johnb2713 and @binky

I am only repeating what the installer has told me.
Now it could be find for commercial, hospital etc.. but not for residential.

However, as I know nothing about this, I thought I looked around and also ask my favorite forum.
When I know more I'll post it here, but if somebody knows, please share. THank you

The only thing I'm aware of is the system must not be able to back feed into the grid in order to protect their workforce. On my system the contactors cannot physically connect any EPS output to the incoming grid.

 

[Bob Smith]

The only thing I'm aware of is the system must not be able to back feed into the grid in order to protect their workforce. On my system the contactors cannot physically connect any EPS output to the incoming grid.

and also if an electrician is working at your house and shut off the main, there must also be one switch for the batteries...

 

[binky]

and also if an electrician is working at your house and shut off the main, there must also be one switch for the batteries...

Which is why you have isolators next to the board and warning stickers

 

[johnb2713]

Warning labels and isolator switches on the inverter.

 

[michael8554]

"in the event of power loss the contactor disconnects the incoming L & N and connects my consumer units to the EPS's."

My understanding is that the maintained equipment should be on a separate earth.

If there were a fault on the maintained equipment during power loss, the earth going back to the grid could be live.

Not good for the grid workers.....

 

[johnb2713]

"in the event of power loss the contactor disconnects the incoming L & N and connects my consumer units to the EPS's."

My understanding is that the maintained equipment should be on a separate earth.

If there were a fault on the maintained equipment during power loss, the earth going back to the grid could be live.

Not good for the grid workers.....

I have an earth rod nailed into the ground.

 

[bladerunnerpv]

This link may be helpful...
https://www.deegesolar.co.uk/eps_for_solar/