Voltage protector

[janclaes47]

I know I'm a bit late with this, but I'm out of the country in a week from now, and currently we get quite a few brown outs.

 

Only yesterday we ran at around 80V for more than 5 hours.

 

When this happens when out of the country, I obviously can not disconnect fridge and pumps, and I don't fancy coming back to a bunch of burned out appliances.

 

I looked on Lazada but couldn't find one, but we all know how useful the search function is on there, and for Ebay or Ali it's too late.

 

Any idea where to get this quickly, and does something like a whole house protector exist at democratic price?

[bankruatsteve]

If your concern is running equipment at 80v then you need an over-under relay.  That will have voltage range you can set and will trip when voltage drops/exceeds the setting.

 

An AVR (AVS) can stabilize voltage to 220v from a range of about 180v to 240v and most will trip when over/under that range.  A bit more expensive but a good addition to handle Thai voltage.

[janclaes47]

I look for an appliance that cuts off all electric when it goes under a certain voltage, and would need it quickly

[bankruatsteve]

Global House carries AVS and do installation (I think).  I think would need to order the over/under breaker.  If Crossy comes by, he can tell you for sure.

[janclaes47]

I don't really need the stabilizer, i'm cheap charlie, just an appliance that cuts of but reset automatically when full power returns

[lopburi3]

Your compressors/pumps are not going to be able to start at 80v and will have overheat protection so do not believe they will be damaged.  This is very common here (70-80v) when one fuse blows on a transformer and if it were a serious issue there would not be any appliances surviving - but that is not happening.  Relax.

 

If concerned you can kill the main breaker (every house has that) and wait until neighbors report electric working again.  

[janclaes47]

Just now, lopburi3 said:

If concerned you can kill the main breaker (every house has that) and wait until neighbors report electric working again.  

Bit difficult when out of the country.

 

Yesterday I heard very strange noises from my inverter fridge while running on 70 - 80V.

 

The fridge is plugged in a Watt-0-meter, and the lcd screen on that meter was flashing all the time, so i guess it was going on/off every second.

[lopburi3]

11 minutes ago, janclaes47 said:

Bit difficult when out of the country.

The I (travel) and we (home) in OP made me believe there would be someone in house who could switch breaker off.   Yes there will be noise as units try to start and always good to remove power - but as said it is common and most people do not seem to have serious issues.  Have been living here since 1975 and have never had a refrigerator, or other, compressor failure and only pump failures have been electrical shorts.   

[johng]

I think you're looking for something like this

( someone else's photos from this forum  sorry can't remember who)

 

[Crossy]

AliExpress have all-in-one units, but you're not going to get it very quickly I'm afraid.

 

https://www.aliexpress.com/store/product/80A-220V-adjustable-automatic-reconnect-over-voltage-and-under-voltage-protection-device-relay-with-Voltmeter-voltage/300086_32817315486.html

 

 

[bankruatsteve]

5 hours ago, johng said:

I think you're looking for something like this

( someone else's photos from this forum  sorry can't remember who)

 

Just wondering if you know much about how this works.  IE: it seems to be a contactor versus something that would be in-line to the mains supply.  Basing this on the 5 amp rating and the DPDT switch.

 

 

[johng]

3 minutes ago, bankruatsteve said:

Just wondering if you know much about how this works.

Sorry no idea at all about how it works...the one that @Crossy  posted about seems like a better (much cheaper too) option.

[Crossy]

7 minutes ago, bankruatsteve said:

Just wondering if you know much about how this works.  IE: it seems to be a contactor versus something that would be in-line to the mains supply.  Basing this on the 5 amp rating and the DPDT switch.

That unit is intended to drive a contactor to switch the load.

 

The one I linked will switch the load directly although I don't think I'd want to go to 80A continuous with it.

[janclaes47]

2 hours ago, Crossy said:

AliExpress have all-in-one units, but you're not going to get it very quickly I'm afraid.

 

https://www.aliexpress.com/store/product/80A-220V-adjustable-automatic-reconnect-over-voltage-and-under-voltage-protection-device-relay-with-Voltmeter-voltage/300086_32817315486.html

 

 

Muchos gracias senhor.. My Portuguese isn't as good as yours obviously, but does this thingy open at the set voltage and close again when full power returns?

 

What you mean with, i wouldn't want to go to 80A?

 

My transformer is 30Kva, and there is a 100A breaker below the transformer, but the RCD's ( or whatever they call) are 63A

[Crossy]

Hmmm, set the language top right of the page ?

 

Yes, you set the high and low limits and it kills the power if the voltage goes outside those limits, about 30 seconds after normal power is restored it turns on the output again.

 

What rating is the main breaker on your distribution board? If it's bigger than 63A you really need to use a contactor, you can drive the contactor using the over/under device.

 

Something like this https://www.aliexpress.com/store/product/TOCT1-2P-100A-2NO-230V-50-60HZ-Din-rail-Household-ac-contactor/300086_32788936046.html

 

 

[janclaes47]

Just now, Crossy said:

Hmmm, set the language top right of the page ?

 

Yes, you set the high and low limits and it kills the power if the voltage goes outside those limits, about 30 seconds after normal power is restored it turns on the output again.

 

What rating is the main breaker on your distribution board? If it's bigger than 63A you really need to use a contactor, you can drive the contactor using the over/under device.

 

Something like this https://www.aliexpress.com/store/product/TOCT1-2P-100A-2NO-230V-50-60HZ-Din-rail-Household-ac-contactor/300086_32788936046.html

 

 

Main breaker is 63A, and luckily all the devices that are sensitive to under voltage are on the same circuit.

[Crossy]

1 minute ago, janclaes47 said:

Main breaker is 63A, and luckily all the devices that are sensitive to under voltage are on the same circuit.

Even better, you can use the over / under unit on its own, protect only that circuit if you wish ?

 

[janclaes47]

1 minute ago, Crossy said:

Even better, you can use the over / under unit on its own, protect only that circuit if you wish ?

 

Thanks, i'm gonna contact the seller, as i see with DPEX it's only 6$ and 7 - 15 days.

 

I have good experience with DPEX, so it might arrive on time

[bankruatsteve]

33 minutes ago, janclaes47 said:

Thanks, i'm gonna contact the seller, as i see with DPEX it's only 6$ and 7 - 15 days.

 

I have good experience with DPEX, so it might arrive on time

Be aware that the unit is "DIN mount".  IE: if you have a "Square-D" CU box, it won't fit and will require it's own separate box.

[sometimewoodworker]

This is an alternative if you can't get that one quickly. 

 

The under/over is potentially switching more than the rated 40A so going through a contactor.

 

[janclaes47]

29 minutes ago, bankruatsteve said:

Be aware that the unit is "DIN mount".  IE: if you have a "Square-D" CU box, it won't fit and will require it's own separate box.

My breakers are ABB

[Naam]

8 hours ago, bankruatsteve said:

Global House carries AVS and do installation (I think).  I think would need to order the over/under breaker.  If Crossy comes by, he can tell you for sure.

an AVS is useless as it can't handle 80volts. the three AVS i installed 2½ years ago are useless too although in the very beginning they handled once for a few minutes a drop to ~130v cranking out 225v. since then they never even started up once as our voltage is steady.

[bankruatsteve]

1 hour ago, Naam said:

an AVS is useless as it can't handle 80volts. the three AVS i installed 2½ years ago are useless too although in the very beginning they handled once for a few minutes a drop to ~130v cranking out 225v. since then they never even started up once as our voltage is steady.

Actually, it can.  I have two AVS (one for up, one for down).  The up has very low load - usually less than 1 amp.  At times when the phases go strange and voltage drops to 80-90v, the down unit trips but the up unit transforms to 220v and everything good there.  Maybe useless to you but mine are doing their job and doing it well.

[Naam]

16 minutes ago, bankruatsteve said:

Actually, it can.  I have two AVS (one for up, one for down).  The up has very low load - usually less than 1 amp.  At times when the phases go strange and voltage drops to 80-90v, the down unit trips but the up unit transforms to 220v and everything good there.  Maybe useless to you but mine are doing their job and doing it well.

i'm not surprised as i have learned that miracles happen in Thailand quite often.

[lopburi3]

30 minutes ago, bankruatsteve said:

Actually, it can.  I have two AVS (one for up, one for down).  The up has very low load - usually less than 1 amp.  At times when the phases go strange and voltage drops to 80-90v, the down unit trips but the up unit transforms to 220v and everything good there.  Maybe useless to you but mine are doing their job and doing it well.

1 Amp draw I suspect is the key - almost nothing.  Expect Naam is talking whole house units as I used for communications prior to retirement in 1992 - and they sure did not convert 80v to 230v.

[Naam]

8 hours ago, lopburi3 said:

1 Amp draw I suspect is the key - almost nothing.  Expect Naam is talking whole house units as I used for communications prior to retirement in 1992 - and they sure did not convert 80v to 230v.

Quote

The up has very low load - usually less than 1 amp. 

1a low load WHEN?

[bankruatsteve]

12 hours ago, Naam said:

i'm not surprised as i have learned that miracles happen in Thailand quite often.

I suppose the conditions that define a miracle are a matter of perception but it's good to hear you are still learning.  ?

[Naam]

19 hours ago, lopburi3 said:

1 Amp draw I suspect is the key - almost nothing.  Expect Naam is talking whole house units as I used for communications prior to retirement in 1992 - and they sure did not convert 80v to 230v.

yes i am talking of 3 AVR / 25 kVA for each phase.