Selecting and installing an AVR for the home.

[Mama Noodle]

I made this topic about the voltage problem at our house:

 

 

And it looks like im going to have to break down and buy an AVR. The voltage drops are murdering the efficiency of my aircon fan speeds and ceiling fan speeds. 

 

I have read the stickies but can't decide on how to move forward. Looking at @Crossy basic diagram here:

 

 

The problem im having is figuring out the best way to wire the AVR up. Going by the basic diagram above it would seem that It would be easiest to buy a huge one (expensive, likely dont have one big enough) and just let the AVR effect everything in the consumer unit. I still ave 4 slots available in the consumer unit right now. 

 

The other choice is to split my existing consumer unit into 2 and have one for AVR stuff and the other for non AVR stuff. Problem with this is that I have ZERO slack in any of the wires in the unit right now, and ZERO slack in the wiring in the wall. Its all trimmed and fit right up to the termination. 

 

Im leaning toward splitting the consumer unit, buying a 15KVA AVR, and only running my aircons, ceiling fans, and home office. Pumps, heaters, fridges and freezers aren't bothering me much. 

 

Whats the best way to add an AVR to a home that has a basic consumer unit and no slack in any of the wiring? 

 

[Crossy]

I'd put the power outlets on it too, 15kVA ought to manage everything apart from water heaters.

 

Wires too short, splice extra onto the end using your favourite method, I use yellow Wago connectors because they're quick and easy but twist-solder-heatshrink would work too and take up less space.

 

Is your consumer unit a plug-in type (Schneider / Square-D) or DIN rail (ABB and others)?

 

How to make a lineman's splice (they're pretty good even without solder):-

 

 

[tifino]

it is exactly the same mechanical method used when joining electric fence wire on the farms. It'll never undo by itself ???? 

  I did the NASA accredited HRHS course over 1977/78, and well... the first thing that worried me, was her Not using anti-wicking tweezers, to prevent that ingress of solder flow back up under that melted insulation. A source point to find corrosion later on... 

[Crossy]

3 minutes ago, tifino said:

... to prevent that ingress of solder flow back up under that melted insulation.

 

Long (long, long) ago as an RN apprentice we were taught to not melt the insulation.

 

Sadly, either I've forgotten, or, much more likely, modern insulation melts rather more easily.

 

In reality in a domestic consumer unit it will be just fine with heatshrink over the lot.

[Mama Noodle]

28 minutes ago, Crossy said:

Wires too short, splice extra onto the end using your favourite method, I use yellow Wago connectors because they're quick and easy but twist-solder-heatshrink would work too and take up less space.

 

Is your consumer unit a plug-in type (Schneider / Square-D) or DIN rail (ABB and others)?

 

How to make a lineman's splice (they're pretty good even without solder):-

 

Its a DIN rail ABB plastic box. 

 

Thats a boat load of work as I would have to splice about 50 wires at the very least with zero space for my hands and no fixture. Wago clips would work but space is an issue. 

I was kind of thinking about buying an electrical cabinet, filling it with DIN rails and using insulated double row Bus Bars for the splices. Then I could construct the box off to the side, get everything ready, and then swap it all out alot faster with less sweating and cursing. 

Does that sound like overkill/over the top? 

[Crossy]

8 minutes ago, Mama Noodle said:

Does that sound like overkill/over the top?

 

Could be a good solution, loads of DIN mount terminals about for a nice neat job.

 

I get mine from this chap 

https://wonkedq.aliexpress.com/store/900082003?spm=a2g0s.9042647.0.0.77ec4c4dOW1ojf

 

 

[tifino]

20 minutes ago, Crossy said:

 

Long (long, long) ago as an RN apprentice we were taught to not melt the insulation.

 

Sadly, either I've forgotten, or, much more likely, modern insulation melts rather more easily.

 

In reality in a domestic consumer unit it will be just fine with heatshrink over the lot.

even now; I couldn't 'bear' to solder some insulated wire, without my trusty 

 

this another simpler 'civvy' variation:  axctually more practical, to suit different AWG sizes - and easier to scratch build! 

 

[Mama Noodle]

22 minutes ago, Crossy said:

 

Could be a good solution, loads of DIN mount terminals about for a nice neat job.

 

I get mine from this chap 

https://wonkedq.aliexpress.com/store/900082003?spm=a2g0s.9042647.0.0.77ec4c4dOW1ojf

How long does it take to get orders from China nowadays? 

 

Have you ever seen these terminal blocks in the regular Thai shops? Thai Watsadu etc? 

[Crossy]

2 minutes ago, Mama Noodle said:

How long does it take to get orders from China nowadays? 

 

I just got one in 14 days, but I have others that have been (apparently) stuck for months.

 

You'll need a proper electrical specialist if you hope to find them here.

[Mama Noodle]

33 minutes ago, Crossy said:

You'll need a proper electrical specialist if you hope to find them here.

These would be passable? 

 

https://www.lazada.co.th/products/screwed-terminal-block-onka-made-in-turkey-i827260616-s1695162297.html?spm=a2o4m.seller.list.127.48342854tgE7eQ&mp=1

 

https://www.lazada.co.th/products/2-double-level-screwed-terminal-block-onka-made-in-turkey-i830856888-s1700042601.html?

[Crossy]

6 minutes ago, Mama Noodle said:

These would be passable?

 

I reckon so ????

 

[bankruatsteve]

Maybe I don't understand the issues being presented. For me, I put AVR between transfer switch for mains/genset and my 2 CUs. (have 2 AVRs). I don't use hot water when on Gen. Otherwise, my 10kVA AVR works fine with voltage varying from 210 to 250.

[Mama Noodle]

1 minute ago, bankruatsteve said:

Maybe I don't understand the issues being presented. For me, I put AVR between transfer switch for mains/genset and my 2 CUs. (have 2 AVRs). I don't use hot water when on Gen. Otherwise, my 10kVA AVR works fine with voltage varying from 210 to 250.

 

I dont have a genset and ive only got one consumer unit. 

 

So either I have to get an AVR big enough to cover the whole load on the current CU I have, or somehow split everything so I can run an AVR on selected appliances. 

 

Unless im missing something or there's a better way? 

 

My voltage varies from 180-ish to 250-ish with the average being 195-240

[bankruatsteve]

Didn't see if you posted your normal load  For me a 10kVA handles everything. Just put between mains and your CU if you want to keep things simple. 

[Mama Noodle]

10 minutes ago, bankruatsteve said:

Didn't see if you posted your normal load

 

Normal load is around 3-5 amps on the low side and upward of 40 amps on the high side, but I can get it even higher than that if I'm not careful. 55 Amps is not unheard of if I turn everything on, which I don't, but it is a possibility. 

 

12 minutes ago, bankruatsteve said:

For me a 10kVA handles everything. Just put between mains and your CU if you want to keep things simple. 

 

That would be ideal but im not sure if thats feasible with the above noted load? What size one do you think would work with that kind of load? 

[Metropolitian]

Wait a nanosecond...

 

What if the OP ( @Mama Noodle ) has the same problem as another member ( @carlyai ) in his thread .

 

Quoted:

On 5/16/2020 at 9:44 PM, Mama Noodle said:

Take an air conditioner for example. Its running, maintaining air temp. The voltage/supply drops then comes back up again, drops and comes back up again over and over

And:

On 4/27/2020 at 4:26 PM, carlyai said:

If I look at the pool pump voltmeter, it reads sometimes at 185v and other times at 250v. ... I have watched the pool pump voltmeter and with no load it can jump from 220v to 250 v and back to 220v.

 

And his problem was solved by:

On 4/29/2020 at 11:54 AM, carlyai said:

SUCCESS. Short story. All now OK.

... They took the cover of the meter and the PEA connections were lose. The guy said all of them. So tightened them all up and everything works again.

 

Maybe the same wonders would do for Mama Noodle.

 

 

[Metropolitian]

3 hours ago, Mama Noodle said:

Thats a boat load of work as I would have to splice about 50 wires at the very least with zero space for my hands and no fixture. Wago clips would work but space is an issue. 

First thought there is no need for splicing 50 wires as you said having an ABB (or like) Din Rail CU.

Well, you can order the breakers in two groups and split the live busbar.

Heavy loads on the left just right after the mainbreaker/rcbo and the AVR groups on the right.

With CU in the UK style with the main breaker on the right, then the other way round.

 

With most AVRs only 4 wires are needed to the AVR (two live , one neutral and one earth).

 

If you can , take a photo of your CU with the cover off we like to look under the sk... bonnet ????.

Then we can come with good suggestions.

 

 

[Mama Noodle]

8 hours ago, Metropolitian said:

Maybe the same wonders would do for Mama Noodle.

 

After I made the original thread, the wife went to PEA and filed a report with them about the problem, and that generated a work order for a crew to come by. They went through and tightened all the connections at the meter and all the way up to my consumer unit - which I went through and made sure (for the 5th time LOL) that everything was tight as well. The voltage problem exists just the same at the PEA's supply line (pre-meter) as it does at my consumer unit. 

 

The PEA sent a different crew this time and them having a work order they seemed to try alot harder. They said they had a few houses complaining about the same issues and that they moved a few of the houses around on the power lines to spread the load around. 

They said go back and file another report if nothing changes, and that they would need to apply for money from the 'head office in Korat" to install another "Pot" (assuming 3 phase/transformer) closer to our end of the line. This solution could take up to a year... 

 

So here I am thinking about installing an AVR ????

[bankruatsteve]

10 hours ago, Mama Noodle said:

That would be ideal but im not sure if thats feasible with the above noted load? What size one do you think would work with that kind of load?

Post #2 could be your answer. (Crossy suggested 15kA)  I run the water heaters through my AVR with no issue.

[Mama Noodle]

9 minutes ago, bankruatsteve said:

Post #2 could be your answer. (Crossy suggested 15kA)  I run the water heaters through my AVR with no issue.

 

Thinking it through, if I do it this way and there's a problem with the AVR then there's a problem with my entire house correct? So if I overload it or it breaks somehow, then my whole house is out of power. 

 

Some sort of bypass switch would be a good idea, right? 

[bankruatsteve]

42 minutes ago, Mama Noodle said:

Some sort of bypass switch would be a good idea, right? 

Sure.  But, easy enough to re-configure without a switch.  BTW: they have internal overload protection so you don't need to worry about that.

[Mama Noodle]

48 minutes ago, bankruatsteve said:

BTW: they have internal overload protection so you don't need to worry about that.

 

So if its overloaded it'll cut out on its own and bypass internally? Or it'll cut out and thats it, whole house is blacked out? 

 

Excuse the layperson questions, just want to make sure my head is wrapped around it. 

[bankruatsteve]

12 minutes ago, Mama Noodle said:

So if its overloaded it'll cut out on its own and bypass internally? Or it'll cut out and thats it, whole house is blacked out?

It acts like a normal current breaker.  Whole house is black.  You turn off the last thing turned on (or whatever to reduce load) and re-set the breaker.  Lights on - no problem.

[Mama Noodle]

1 hour ago, bankruatsteve said:

But, easy enough to re-configure without a switch.

 

Last question for now ????

 

What about if the sucker breaks or stops working, say, in the middle of the night and its not a thermal/current overload, its a parts failure - is there a simple re-config? Or would a solution require getting into the CU and moving wires in the middle of the night? 

 

Trying to look ahead and avoid drama down the road. 

[bankruatsteve]

2 minutes ago, Mama Noodle said:

 

Last question for now ????

 

What about if the sucker breaks or stops working, say, in the middle of the night and its not a thermal/current overload, its a parts failure - is there a simple re-config? Or would a solution require getting into the CU and moving wires in the middle of the night? 

 

Trying to look ahead and avoid drama down the road. 

@Crossy had a thread on that subject (a year ago?)  I've never had an issue with mine.  A simple cross-over switch (same as for mains/genset) would keep your night mostly uneventful in that case.  The CU would not be involved in any case.

[Crossy]

Get a cheap manual generator transfer switch and wire it as shown in this thread

 

 

[Mama Noodle]

9 minutes ago, bankruatsteve said:

The CU would not be involved in any case.

 

The CU itself wouldnt be involved, but the supply to it would be, and without a bypass something would have to be done in there to get straight mains power back to it? 

[bankruatsteve]

1 minute ago, Mama Noodle said:

 

The CU itself wouldnt be involved, but the supply to it would be, and without a bypass something would have to be done in there to get straight mains power back to it? 

No.  Everything can be done at the AVR.

[Mama Noodle]

10 minutes ago, Crossy said:

Get a cheap manual generator transfer switch and wire it as shown in this thread

 

Ok I can follow this, but one question - In that thread you say that the switches are interlocked. 

This means that its not possible to have them both sides closed at the same time, correct? In other words, if you flip one side, the other, opposite side will flip the opposite way? 

[Metropolitian]

2 hours ago, Mama Noodle said:

 

Ok I can follow this, but one question - In that thread you say that the switches are interlocked. 

This means that its not possible to have them both sides closed at the same time, correct? In other words, if you flip one side, the other, opposite side will flip the opposite way? 

Both can down at the same time. But never up at the same time.

 

So in fact the switches are not interlocked at all, only at the top inside whatever is pulling the link.