Quote for EPS connection

After 8 power cuts in my area since mid Jan it pushed me to get a quote to have the EPS connected. Does this price sound correct? If anyone else has had this done I would like to know if the price is good.

£700 + VAT
Manual switch over for whole house.
EPS on a single AC3 (second one being added once the EMS is available)

The plan, in the event of a cut turn off all the fuses in my consumer unit. Go outside to my battery and turn the switch to isolate from the grid. Turn back on fuses keeping the load below 3kw 13a, so down stairs sockets to have the fridge running and internet etc.

Sound about right? Sadly the quote does not have the full details it just says
SUPPLY AND INSTALLATION OF EPS CHANGE OVER SWITCH FOR GIVENERGY BATTERY SYSTEM

Think I paid £500 incl VAT for a simple EPS double socket. Felt a bit expensive, but for the peace of mind...

Are they also fitting an independent earth?

How will you know when the power is back on if you switch the whole house over to EPS?

(Other than having a walk down the road, or monitoring the DNO website).

THALL
Will an AC3 actually operate without mains power? Surely this is part of the G98 (etc circuitry).
If you flick the switch to isolate the grid, then any power workers upstream will be safe, but what will override the G98 features that "tell" the AC3 all is safe?

Seems a lot for a "switch".
Have you got a TTS earth and is that part of the quote?

TX200 The quote does not list details, so no idea about an independent earth.

Power back on, all my neighbors around me. Their lights will come back on 🙂 Then I have to turn off the fuses, go back outside and turn the switch, come back in turn everything back on. But this way I can control the load. Make sure the ASHP fuse stays off etc. But can have the fridges run, TV, internet etc, small stuff.

THALL Difficult to say without the details. A simple manual triple pole changeover switch can be got for under £100. A solax changeover specifically designed for solar/battery systems (and includes additional protection so is not just a switch) is around £350. Depending on the installation site and cabling requirements say 2-3 hours engineer time including testing and certification and you are nudging towards your quote. I would say it's maybe top end so make sure you are getting the best. Also, if you are adding additional AC inverter capacity, consider ensuring that the supporting cabling installed can handle any extra EPS capability to reduce further costs when you upgrade.

A note for the future. If you ever need your house rewiring and/or the consumer unit replacing, split your EPS circuits between two consumer units then its a lot easier to isolate all the other circuits when you need to and control what actually gets connected to the EPS.

Sorry TT earth

Better ask your electrician to make sure your DNO allows it.
You might be capable and competent to make sure that there is no back feed into the grid at the "wrong" time, but it does not mean everyone is.
That is why they must have certified G98(etc) safety circuits on the inverters

SteveCook It can, all GE inverters have an EPS circuit that can provide power in the event of a grid outage. I have asked for more details, but the guy did my solar install and suggested the EPS change over switch at the time. But the plan was to do it the sametime as adding a second AC3. But due to frequent powercuts I would like to get the option added sooner rathe than later. Had 8 cuts since Janurary including one on my birthday which ruined the evening.

cluelesscris I would hope the cabling is ready for the second AC3. As mentioned above this idea was linked to getting a second AC3, but I would like it done sooner. The guy knows I want a second AC3 but he's not willing to install it given the problems with multiple AC3's at the moment. But I have asked for more details. I did go over it with the guy back in October but I can not remember everything he suggested.

Splitting the consumer unit into two might be essential if you're going to have two AC3s providing EPS output?

Not aware of the details of the new EMS box. Would it keep two inverters running at the same frequency or just control their output wattage?

If the latter, you don't want two independent generators powering the same circuits.

As for the earth, you can't rely on grid earth during a power cut. So you'll need a new earth (if the house hasn't already got its own independent earth).

Oh and each house on the street will be on one of three phases of electric. So you need to find the houses on your phase to work out if you/they are back on power.

Seeing a few houses with visible electric might not be enough to know if yours is back. 😁

And some of them might have battery systems installed too. 🤣

I know very little about the new EMS. It is meant to prevent things like 1 battery draining in the other and vice versa. Meant to correct some data issues when running multiple inverters etc. But are you saying having mutliple AC3 might conflict with each other? They wont balance themselves to give me a total of 6kw on the EPS? I will ask my installer as that changes my plans.

But no, none of them have battery systems. They all have a few solar panels but noting to the extent I have done. The small development is only 3 years old. All of the houses had 2 - 3kw worth panels fitted, every house with an ASHP etc etc. 100% electric, every single house.

THALL they might give you the total, but not necessarily in a healthy fashion. Some things might go pop. I'm not an electrician, but it doesn't sound like a good idea to me.

TX200 That is disapointing. But I have messaged the guy to check. While 3kw is enough for the lights tv and internet, microwave at a push. I was hoping for the full 6kw in the future so my ASHP could run. I will double check with the guy. Cheers for your help.

Cheers to everyone for the very quick replies.

You CANNOT combine EPS outputs. The internal frequency isn't synchronized.
Both will go pop if you try.

You could have both on EPS, but one at a time, a 3 way switch, Inverter1, till battery dead, then inverter 2, or grid

THALL I take it you've seen the EPS documents/designs on the givEnergy KB site?

Unless the gateway or EMS device solves the problem of multiple generators running off grid, you'll probably need something like this?:

A grid consumer unit with a MCB for the current AC3 and at least one spare for the new AC3

A manual changeover switch connecting your existing AC3 to a new consumer unit with half your house circuits in it, plus a feed from the grid consumer unit (via the changeover switch) for normal operation e.g. when not needing EPS.

A second manual changeover switch for the new AC3 and another consumer unit (with the other half of your house circuits in it). Fed exclusively from the grid consumer unit, until your new AC3 arrives.

TX200 Yes seen it. I think option 3 is what my sparky is looking at/going for.

Just checked with GE as the chat option is working. Each AC3 has to power its own set of circuits, I would not get a total output from multiple inverters to power a single device. So I could run 2x 3kw devices which is not what I wanted. So for EPS the limit would be 3kw for the whole house switchover. Only way to get 6kw would be to get the All In One with its 6kw output. So I need to ask myself is £700 + VAT worth it with a 3kw limit. So lights, internet, TV, microwave.

My ultimate goal was to be able to run my ASHP if I had too. Highest draw I have seen from that is 3.8kw so simply not possible with AC3's

THALL
To use the EPS you also need a 25A double pole RCD to protect it from overloading so the size of the battery almost doesn't matter anyway. You're not going to be getting much more than 2.7kW before it trip

This is also what pushes the price up, it almost doesn't matter if you have just a double socket or a change over switch. You still need a new consumer unit with the 25A RCD plus the extra earth stake and cabling

https://kb.givenergy.cloud/assets/EPS%20Configuration%20v2.pdf

I suspect that the £700 is for fitting a twin socket, installing an earth rod and connecting three wires. Total material cost - £20 ish. If you are lucky they will test the ground spike. If you think that's expensive wait for fitting an 'EMS'. North of £1500 ?
Installing the EMS should be fixing a small box to the wall, connecting a couple of RJ45 cables and then enabling EMS via the 'engineers portal'. May also include removing inverter dongles and enabling EMS to router comms.
I've asked Givenergy a couple of questions about Modbus IDs and about EMS. They either don't answer the question or are evasive. Why they thought the Modbus comms between the inverters would work I've no idea. Until they release EMS don't fit two inverters. That leaves people like me who already have two way up a creek withoult even a boat. Wait for Q2 when it's released - trouble is they didn't say which year ...

Shatch would be option 3, island mode.

Slartibartfast Nope not a twin socket, for whole house manual switch over. Bit scary with your EMS guess though! My installer suggested most of the cost will be for the device itself rather than his labour. If the EMS takes over comms too I hope it has a wired port rather than needing wifi.

Shatch True. I just had a double socket EPS added to my HY3.6. The Givenergy KB document method 1 shows a double socket connected to the inverter EPS terminals but, when the electrician took the Givenergy training course, he was given a different diagram with the added consumer unit between the EPS terminals and the double socket. Looks like the KB documents aren't 100% accurate.

Slartibartfast My TT earth point, double socket and consumer unit cost £500 for local electrician to install. He also took the Givenergy training course so it was all above board.

I have Method 3 as well.

I wanted a simple method that wasn't at risk of overpowering my inverter. Power goes off.
Turn off any high loads
Flip switch and run off battery and solar.

Hook Sadly for me my solar will not work with the AC3. But even more sadly I can not combine dual AC3's to give me a high single EPS load which changes my plans. Basically trying to justify £700 to keep the lights on for an extra 20 hours per year. The plan was to be able to run the heating in the event of a powercut. In short the missus feels it is a lot of money and would rather have a part of the garden landscaped, new patio etc.

as there is a limited choice of 25a rcd's and as the regs state that devices from different manufacturers should not be mixed, I am wondering about.
the eps feeding an consumer unit with a double pole isolator switch- then a 25a mcb/rcbo- then the bus bar with the final circuits.
I ponder this as to add an EPS CU (consumer unit) would mean moving a few existing rcbo's to the new Cu and there isnt a 25a rcd in the same make (denmans curve)
thoughts?
i am thinking this would constitute an alteration to the OEM spec also so may as well mix and match?

i saw recently on a youtube video if you run the whole house via eps then it essentially is always running via the inverter.. so if you have an inverter issue.. you potentially dont have any electricity in the house until the inverter is fixed/replaced. I wouldn't fancy this as you could be stuck for a few days?

michaelmcgoldrick
agreed, however with just lighting and gas boiler loads the inverter input and eps output could be removed and coupled during that period. though I suppose many would not be capable or comfortable doing that.

Shatch you also need a 25A double pole RCD

Or double pole switch and rcbo;s totalling<_ (less tah or equal to 25a) ?

THALL I had EPS installed using a manual changeover switch and included earthing to a new earth rod for £291.20. This was installed several months after the original installation and took about 3 hours.

Not needed to use it as yet.

Martyn WOW great price compared to mine. At that kind of price I would have it done.

My manual changeover switch to feed essential consumer unit (fridge socket, freezer socket, gas boiler controls, router, and lounge socket for tv and sky box and lounge lights). All pretty low power and below EPS limit.
In normal use the CO switch is set to feed essential CU from EPS output which is always live.
When grid goes off, everything goes "off" except EPS output and we sit in the warm in the lounge watching TV.
If inverter needs to be maintained, CO switch is set to grid and essential CU is fed from a way on the non-essential CU.

alan_johnston Does the consumer unit have a RCD & MCB or RCBO?

The EPS output from inverter (right next to inverter) is RCD as GE note.
The essential consumer unit is single RCD to all circuits
The direct mains feed from dedicated consumer unit for inverter (with trip indicator light) is MCB.
Like GE method 2
The essential CU feeds all the lighting circuits in the house via RAKO units. If the event of power break, all RAKO circuits default to "off" when power is restored. All lamps are LED in any event so max lighting load can only be around 500W with every light in the house on.

RetSparky Electrician provided a separate consumer unit for the EPS circuit. It has a double pole breaker for the EPS supply. Not sure if it's RCD or RCBO. Then the circuit to the EPS socket has an MCB.

Thanks Alan. From your photo it’s a 100A main switch and a 16A RCBO.
My installer said they don’t fit RCB OR RCBO because of nuisance trips.
Plan is to fit a double RCD socket

RetSparky
For EPS you must have a TT earth as grid earth will be lost in island mode.
ON TT earth, regs say must have RCD on output.- see also GivEnergy installation instructions.

https://community.givenergy.cloud/d/3478-type-a-and-type-ac-rccbrcd-experience

alan_johnston I’ve also got an HY 3.6 and it’s in the garage . I had to have a new heavy cable to connect the garage to house consumer unit and smart meter , but have a redundant heavy cable that could take the auto EPS feed from the inverter ( manual switch over ) to the house ( into a small consumer unit ) to feed a double socket for fridge and freezer
Sadly my original installer is a bit reluctant . I knew about the earthing issue . Is this something an EV charger installer could do? With no need to contact GE etc Bill G.

billG I believe you have to have the inverter config changed to say its has an EPS or "there may be warranty issues"...

but you can certainly get an electrician to install the earth spike and cabling, or do it yourself and get the electrician to check/commission it

billG EV charger installer is not likely to want to install a TT earth rod and wiring. They are there to install the EV charger (usually within a few metres of the main feed). It took 2 guys a morning to instal my TT earth point in the garden and run heavy duty earth wire back to the inverer EPS circuitry. The resistance with one rod was a bit too high so they had to sink a second rod and wire that in too.

geoffreycoan yes. Even though my Solar installer was happy for a local electrician to install the TT earth and do the wiring, they still had to re-commission the inverter to say it now had EPS.

Since the subject of earth rods has come up... We're hoping to get a small porch built, which will be on the other side of the garage wall which houses my GE system. I there something I can do while the foundations are being laid to provide the necessary grounding. ISTR that there's some kind of mesh you can put down, to give a good ground connection?

DD The earth rod is basically a large brass rod with a spike on the end hammered into the ground. It needs to in contact with the earth, not concrete.

https://www.toolstation.com/earthing/p36107

geoffreycoan yes, I know what an earth rod is. Question is whether I can do better since I happen to be getting foundations laid anyway.
Unfortunately, there isn't a terribly good place near the system for an earth rod - don't know exactly where the various utilities go, and you're supposed to keep well away from them anyway.

DD what you could simply do is run some ducting to a suitable area of ground away from the house and lay the earth cable through it.

My earth rod was done this way, through the garage wall, along the side of the house then ducted under a footpath to clear earth connection. It doesn’t need to be high tech

you could lay mesh in the ground when you have dug out for the foundations, but if you dont get a low enough resistance you will need to think about a rod.
the beauty of rods is just keep banging them in and connecting them together, so make provision of an earth cable to a suitable point when you start digging