Electrical Power Surge Applications Conundrum.

[CapraIbex]

My aim is to protect our electrical home appliances from power surges. But I am unsure on the requirements of Surge Diverters and Surge Filters in addition to a Whole-House Surge Protector and request advice what's needed for a residence.

 

The village sparky installed a "SAFE-T-CUT Consumer Smart Unit & RCBO Premier" but there aren't any slots left installing additional products (refer to attached photo) but I am prepared buying a new larger c/unit if necessary and available.

 

In addition I intend using voltage stabilizers for TV, computers, fridges and chest freezer as the power supply is not very stable and 'brown-outs' are frequent. The product I'm eyeballing is available at https://www.lazada.co.th/products/stabilizer-avr-schneider-ls1000s-th-1000va-500w-automatic-voltage-regulator-i3350462786-s12429314211.html?search=1 but am concerned about the low joule rating and relative long response time. Any opinions or alternatives of this product are much appreciated also.

 

[Crossy]

Nothing to stop you adding a small DIN box to contain your surge arrestor and it's MCB.

 

Or you could rationalise your circuits to free up an MCB which could then feed your external box.

 

That little AVR looks OK, as you say it's a bit light on surge suppression but give it a nice big beast in the CU and you're gold.

 

[CapraIbex]

18 minutes ago, Crossy said:

Nothing to stop you adding a small DIN box to contain your surge arrestor and it's MCB.

 

Or you could rationalise your circuits to free up an MCB which could then feed your external box.

 

That little AVR looks OK, as you say it's a bit light on surge suppression but give it a nice big beast in the CU and you're gold.

 

The three inactive 20A breakers are meant for 3 air condition units (2x18,700 BTU and 1x8,500 BTU) wired with 6mm square. Could I use only one (1) breaker with a higher rating of Amps? If yes, this would give me 2 additional slots.

[Crossy]

Putting two A/C units on one breaker isn't ideal but shouldn't be an issue.

 

Ideally you incoming surge suppression needs to be connected as close to the incoming supply as possible, so at the left end of your CU. Some shuffling would be needed.

 

Also, a decent 80 or 100kA suppressor is more than one unit wide so it still really needs to live in a separate box, not difficult to arrange.

 

If I was doing it, I'd take the surge suppression directly off the switched side of the main breaker.

 

We have a unit similar to this https://www.lazada.co.th/products/b100-2p-60ka-100ka-385v-ac-1pn-spd-i3487044637-s12946508088.html it's 3 CU positions wide, add to that it's MCB. A "garage" CU box would house it all nicely.

 

[CapraIbex]

1 hour ago, Crossy said:

Putting two A/C units on one breaker isn't ideal but shouldn't be an issue.

 

Ideally you incoming surge suppression needs to be connected as close to the incoming supply as possible, so at the left end of your CU. Some shuffling would be needed.

 

Also, a decent 80 or 100kA suppressor is more than one unit wide so it still really needs to live in a separate box, not difficult to arrange.

 

If I was doing it, I'd take the surge suppression directly off the switched side of the main breaker.

 

We have a unit similar to this https://www.lazada.co.th/products/b100-2p-60ka-100ka-385v-ac-1pn-spd-i3487044637-s12946508088.html it's 3 CU positions wide, add to that it's MCB. A "garage" CU box would house it all nicely.

 

Okay, I won't change the breaker arrangements for the air condition units and obtain from Lazada a 100ka Surge Protector.

 

My search in regard to "garage" CU box to which the surge protector is to be installed was unsuccessful. Would a cabinet as offered by https://www.safe-t-cut.com/en/product/premier-eu-eng/ be adequate for accommodating:
1. the 100ka Surge Protector;
2. the Main breakers; and
3. the RCBO; and then
followed by the existing "SAFE-T-CUT Consumer Unit" containing all other breakers.

[Crossy]

16 minutes ago, CapraIbex said:

My search in regard to "garage" CU box to which the surge protector is to be installed was unsuccessful.

 

There are gazillions on Lazada, a 4 unit one would fit one of the 100kA arrestors and a single pole MCB (you just need to open the live).

 

Something like this https://www.lazada.co.th/products/4-consumer-unit-4-channel-2-4-i2676671412-s9640187556.html

 

Ours came from Mega-Home as I'm the instant gratification type, this one is on our solar inverter hence the 2-pole MCB and smaller arrestors.

 

 

 

 

Or you could get a bigger one and move your incomer and RCBO into it before feeding to your existing box.

 

Many, many ways to go about this job ???? 

 

[CapraIbex]

41 minutes ago, Crossy said:

Many, many ways to go about this job

My apologies, I just am not familiar with the technical lingo pertinent to electrical components.

And since my electrical know-how is limited the "Many, many ways to go about this job" are adding challenges to my attempt explaining all this to the village electrician.

If I understand you correctly:
a) the 4 channel consumer unit will accommodate the Surge Protector and Main Breaker;
b) my existing SAFE-T-CUT Consumer Unit will contain the RCBO and all other breakers; and
c) my existing SAFE-T-CUT Consumer Unit will be installed following the 4 channel consumer unit.

Can I assume that the grounding (earthing) arrangement needs not to be changed?

[Crossy]

No!

 

In the baby box you have the arrestor and a 1-pole breaker (MCB) in the live to protect it.

 

3 wires from the baby box, E goes to the earth bar in your main unit, N goes to the N bar, L goes to the outgoing live terminal of your existing main breaker.

 

Probably the easiest place to pick up the live is from the leftmost terminal on the live bus-bar, a bit of 6mm² should fit in the same terminal with the bus bar.

 

Nothing needs to change in your existing box so that's nice and easy.

 

You can put the baby CU in a convenient place, but keep the wires as short as possible.

 

[CapraIbex]

40 minutes ago, Crossy said:

No!

 

In the baby box you have the arrestor and a 1-pole breaker (MCB) in the live to protect it.

 

3 wires from the baby box, E goes to the earth bar in your main unit, N goes to the N bar, L goes to the outgoing live terminal of your existing main breaker.

 

Probably the easiest place to pick up the live is from the leftmost terminal on the live bus-bar, a bit of 6mm² should fit in the same terminal with the bus bar.

 

Nothing needs to change in your existing box so that's nice and easy.

 

You can put the baby CU in a convenient place, but keep the wires as short as possible.

 

I will pass on the wiring instruction to the sparky; Thanks for detailed explanation.

 

I make certain that the 'baby CU is located as close to the existing box as possible ensuring short wires.

 

There are many pole breaker (MCB) available at Lazada. Could I bother you again for advising the preferred make and correct size?

[Crossy]

I'd go with a 20A MCB, ChinT are a mid range Chinese maker that won't break the bank ???? 

[CapraIbex]

12 hours ago, Crossy said:

I'd go with a 20A MCB, ChinT are a mid range Chinese maker that won't break the bank ???? 

Well, this is quite a selection to choose from. A Lazada search indicates 125 items found for "20A MCB, ChinT" - very overwhelming for non-experts.
I begin to realize that all this is way beyond my capabilities. Since the electrical breaker system is sourced by SAFE-T-CUT I am going to contact them and purchase a new consumer unit with an 80KA Surge Protection Device already installed and then re-install the existing breakers including Main breaker & RCBO to the new box. This will save me from installing a "baby box" and eliminate additional rewiring. I realize that the SAFE-T-CUT SPD rating is lower by 20KA but this just will have to do the trick. But I am going to inquire if SAFE-T-CUT offer a unit with 2x80KA SPD installed.
Thanks again for your expert input and patience for responding.