Figuring out power requirements for new house

[islandguy]

Being queried by PEA office about how much power we might draw to make an estimate for putting in power lines. First quote (500,000 with a 400 meter distance to the line) they thought we were doing a resort and suggested top of the line - I think 100KV - and here I have too admit I don't understand what that actually means. Now I am asking for a quote for a smaller demand, but figuring out the amount of that demand is where I would like help. This would be for a house, with medium demand (fans, occasional ac in one room, lights, kitchen, computers, maybe water heater). However, there will probably be another building or two with small demand and also frequent use of bigger water pumps. Any help? Thanks

[Crossy]

Ok, let's have something to go on, how many bedrooms, bathrooms, pool, workshop?

 

Roughly how many m² of living space (so we can guesstimate aircon load).

 

Do you cook electric?

 

Bigger water pumps? How big? 2 horse, 3 horse, bigger?

 

Most regular farang homes get by on a 15/45 (50A) single-phase supply.

 

What's going to be in the "other building or two"? Just a light or a machine shop?

[tutsiwarrior]

sounds like the local PEA want to run a dedicated transmission line (100kV?) out to his place...with associated GIS substation, etc...

 

there must be some confusion somewhere...the house load should be easy to estimate, probably do it on a m2 basis with a margin for falang sensibilities...

 

 

[islandguy]

Fair enough request. Let's give it a try:

 

One bedroom house with garage area downstairs 

   2/3 room air conditioners

   Electric lights 5 rooms

   Two conputers and a TV

   3 fans

   Kitchen appliances, not including oven

   Washing machine

    

 

Work building 

   Lights and fans for 100 sqm building

   Kitchen with small appliances

   Large TV/music system

 

Group bathrooms

    Electric lights 4 rooms

    Water pump

    Fans

 

outside area

     2 three horsepower water pumps

     Electric weed whipper

    Lights for driveway 

    Webcams

 

And what is the unit they were using for different capacity lines into the property?

 

Thank you much for the help!

[islandguy]

Thai visas search function showed the following (see screenshot below) archived post which I had not found. Helpful. Now I have a concept of max load in A /ampheres. Does the installation vary in the size and capacity of all the parts (wires, insulators, transformers). Does 3 phase require triple the wires? 

[whatawonderfulday]

Seems very high.   As a guide last year I paid 67,500 THB to the PEA to run power from the local road to a small fishing lodge I have built near one of our ponds.  The distance from the power supply in the local road to our lodge is only 200 metres.  It was an additional 4000 THB for a 15 amp meter.   So based on that you should have been quoted IRO  130 to 150 k.

Edited April 1, 2017 by whatawonderfulday

[Crossy]

1 hour ago, islandguy said:

Fair enough request. Let's give it a try:

 

One bedroom house with garage area downstairs 

   2/3 room air conditioners

   Electric lights 5 rooms

   Two conputers and a TV

   3 fans

   Kitchen appliances, not including oven

   Washing machine

    

 

Work building 

   Lights and fans for 100 sqm building

   Kitchen with small appliances

   Large TV/music system

 

Group bathrooms

    Electric lights 4 rooms

    Water pump

    Fans

 

outside area

     2 three horsepower water pumps

     Electric weed whipper

    Lights for driveway 

    Webcams

 

And what is the unit they were using for different capacity lines into the property?

 

Thank you much for the help!

 

That lot will run quite happily on a single phase 15/45 meter, apart from the water pumps.

 

The pumps too would actually be ok, provided you make arrangements so they don't start at the same time (starter timer), they can run together but the start current may open the incomer. We have a 2HP and 3HP single-phase irrigation pumps, they run fine on a 15/45 but they never try to start together.

 

If PEA can do a 30/100 single phase you'll be fine.

 

Do check the cost of 3-phase (15/45), those pumps will be quite a bit cheaper in 3-phase.

 

EDIT And a 3-phase supply will need 4 wires.

[islandguy]

Thanks

[tutsiwarrior]

I wouldn't expect all of the loads to be connected simultaneously but maybe OK for a worst case design scenario...

 

a 15/45 supply can handle 55 amps? that's good to know...

 

 

[Crossy]

12 minutes ago, tutsiwarrior said:

I wouldn't expect all of the loads to be connected simultaneously but maybe OK for a worst case design scenario...

 

a 15/45 supply can handle 55 amps? that's good to know...

 

Assuming it's on a 50A MCB then it will be quite happy at 56A pretty well forever, 100A will open it in 20 seconds or so.

 

Many 15/45s are on 63A breakers, happy at 71A forever.

 

The meters are designed for this level of overload, and then some, 100% continuous overload is not uncommon in the design parameters.

[tutsiwarrior]

yeah...just had a look at the CU and the supply is on a 50 amp breaker...

 

thanks, crossy...

[islandguy]

Thanks all for the info. Talked to a buddy in the US who does general construction and he said most of the (affluent) houses where he is have a 'board' rated for 200 amps. I made an assumption at the time that that was the main hook from the power line into all the separate house lines at the circuit box. We also both remembered that later new legal users along the power line may suck the life out of what gets to me!

[bankruatsteve]

FYI:  A requirement for 200 amps in the states roughly equates to 100 amps here.