Hi Guys, im new to the forum and looking forward to reading some of the questions and advice.

[Steve1]

Hi Guys, im new to the forum and looking forward to reading some of the questions and advice. .
I have been asked to install a safety device / relay system to an existing domestic property 4Kw solar system, so if there’s a main supply power cut to the property, we want the solar panels to trip / disconnect from the mains supply and must be manually reset to the system.
supply 230ac / 6amp breaker. Can you recommend a device.
Best regards Steve

 

[mainline]

Hi Guys, im new to the forum and looking forward to reading some of the questions and advice. .
I have been asked to install a safety device / relay system to an existing domestic property 4Kw solar system, so if there’s a main supply power cut to the property, we want the solar panels to trip / disconnect from the mains supply and must be manually reset to the system.
supply 230ac / 6amp breaker. Can you recommend a device.
Best regards Steve

I would have thought that the inverter would automatically do this.

 

[littlespark]

Agreed. Im not an installer, but have PV on my own roof.
The inverter measures voltage coming into the house, and generates the AC supply from the DC coming from the panels at a few volts more.
If there is no main AC power... ie, powercut, or simply the isolator is turned off, then there is no AC output from the invertor.

 

[Steve1]

Agreed. Im not an installer, but have PV on my own roof.
The inverter measures voltage coming into the house, and generates the AC supply from the DC coming from the panels at a few volts more.
If there is no main AC power... ie, powercut, or simply the isolator is turned off, then there is no AC output from the invertor.

Hi Littlespark, yes I agree with you but the pv will still produce ac via the investor. what I to find is a device that disconnects the pv when the mains supply fails, and the device must be manually reset simmer to a breaker. ; )

 

[pc1966]

What model of PV inverter is it? Anything like that which generates power and is connected to the mains has to shut down in the event of AC failure for safety reasons (so line worked don't get killed).

Also so when the mains returns it is not live but out-of-phase and damaged!

 

[pc1966]

TL;DR What you are asking for can be done, but it should not be necessary.

 

[pc1966]

Regulations are here:

https://www.energynetworks.org/assets/images/Resource%20library/ENA_EREC_G98_Issue_1_Amendment_6_(2021).pdf

Section 10.1.3 requires it to shut down in 2.5 seconds from under voltage (loss of supply).

 

[Steve1]

Hi pc1966, thanks for getting back to me.
I agree with all you say. if im correct as soon as the mains supply power is reinstated the solar system kicks back in and produces ac via the invertor. what I need is for the pv system to be totally isolated once the power fails and not to kick back when the mains supply is reinstated and the pv must be manually switched back on.

 

[pc1966]

Motor starters normally have a no-volt release action for safety, so your band saw, etc, does not burst in to life when mains power comes back on! Something like that would do the job.

But, why? Is there some specific reason you don't want the PV to resume once mains is restored?

Do you plan for a generator?

 

[Steve1]

Motor starters normally have a no-volt release action for safety, so your band saw, etc, does not burst in to life when mains power comes back on! Something like that would do the job.

But, why? Is there some specific reason you don't want the PV to resume once mains is restored?

Do you plan for a generator?

thats a good call, I was hoping there was a bit of kit ready built. maybe ill put together a latching relay circuit .

 

[mainline]

thats a good call, I was hoping there was a bit of kit ready built. maybe ill put together a latching relay circuit .

Where in the supply are you going to isolate the panels ?
What is the make model of your inverter ?