Portable Power Stations

1961Nick

JKenH said:

1961Nick said:

JKenH said:

My electrician came over today and fitted a plug and socket to my OFCH feed so in a power cut I can now have CH heating powered from my PPS. The CH was drawing just over 200watts so potentially I could run that for 9-10 hours from one of my Poweroak EB240 PPSs.

I also asked him if I could use the PPS to power the house from the grid by switching off the main isolator in the consumer unit (in mine it’s a big red switch) and he said that should be ok in theory but I would also need to isolate the solar pv installation or the panels would back feed into the PPS output and probably wreck it. (The chances are quite high that I would forget to do this.) Obviously I would have to be careful what load I placed on the system but it should be possible to have some LED lighting and low power items such as an LCD, the router etc running and the convenience of switching lights and appliances on and off around the house as required rather than having extension leads trailing everywhere.

That’s the theory, anyway, but I have not dared to try it yet. I am wondering if anyone with batteries and an emergency back up outlet has actually tried plugging the house in. 

I have a 'Generator input plug' fitted to my supply with a changeover switch that breaks the grid connection & makes the connection to the generator plug. I can then plug it into the battery EPS, a petrol generator or I could use a PPS.

I would have liked to make it automatic with a changeover relay but the surge is so great that it trips the battery inverter unless I bring the circuits back one by one.

What happens to your solar generation when you switch to battery?

I start with all the breakers off so that includes the battery & solar breakers which remain off. Most power cuts are relatively short so I usually just turn the u/s ring & the lighting back on. Turning the downstairs ring on involves going round turning everything off to reduce the surge & then bringing the appliances back one by one. It's probably just one thing causing the surge but I've not identified the culprit yet although fridge/freezer compressors are high on the list.

1961Nick

The surface mounted commando is a plug. The trailing flex has a socket on the end of it.

QrizB

1961Nick said:

The surface mounted commando is a plug. The trailing flex has a socket on the end of it.

Very tidy. I've looked at those ESR transfer switches a few times myself, but haven't yet committed to one!

ispookie666

@QrizB Transfer switches are not that difficult to make.  I used two relays and contactors to make an ATS.  
@1961Nick very neat.  
I need to check if my panels would keep generating when the grid goes down but the Emergency backup power is up and running.  

chris_n

What type of earthing does you house have? If you have no mains you may also have no earth.

JKenH

chris_n said:

What type of earthing does you house have? If you have no mains you may also have no earth.

I don’t know how to describe the earthing but it is standard for a dwelling house and presumably complies with electricity regulations.

I believe the earthing requirements for PPSs are similar to portable generators. 

Good point, though.

1961Nick

JKenH said:

chris_n said:

What type of earthing does you house have? If you have no mains you may also have no earth.

I don’t know how to describe the earthing but it is standard for a dwelling house and presumably complies with electricity regulations.

I believe the earthing requirements for PPSs are similar to portable generators. 

Good point, though.

Your house probably has a protected multiple earth (PME) which will continue to function when there is no mains supply (assuming the mains fault isn't a neutral/earth fault - rare because there are multiple earths).

JKenH

1961Nick said:

JKenH said:

chris_n said:

What type of earthing does you house have? If you have no mains you may also have no earth.

I don’t know how to describe the earthing but it is standard for a dwelling house and presumably complies with electricity regulations.

I believe the earthing requirements for PPSs are similar to portable generators. 

Good point, though.

Your house probably has a protected multiple earth (PME) which will continue to function when there is no mains supply (assuming the mains fault isn't a neutral/earth fault - rare because there are multiple earths).

I will take your word for that, Nick, thanks, (although I don’t actually understand it).

1961Nick

JKenH said:

1961Nick said:

JKenH said:

chris_n said:

What type of earthing does you house have? If you have no mains you may also have no earth.

I don’t know how to describe the earthing but it is standard for a dwelling house and presumably complies with electricity regulations.

I believe the earthing requirements for PPSs are similar to portable generators. 

Good point, though.

Your house probably has a protected multiple earth (PME) which will continue to function when there is no mains supply (assuming the mains fault isn't a neutral/earth fault - rare because there are multiple earths).

I will take your word for that, Nick, thanks, (although I don’t actually understand it).

This is a fairly easy to understand description of how PME works & potential risks.

https://professional-electrician.com/technical/tnc-s-supplies-for-outbuildings-thinking-outside-the-box-napit/

Ectophile

As a rule, if the grid supply to your home has failed, you can't assume that the supplier's earth connection is still working.  It may well be, but it might not.

If you are intending to run off a separate generator (including a solar installation with a battery), then you should have your own independent earth.  This is usually an earth rod, but other metal things may work.