My house is with 4 airconds and sometimes all 4 are on at the same time.
Single story house with 3 rooms and 1 living to give an idea why 4 airconds.
Lots of laptops hanging around, at least 4 and 1 PCs. So far with everything on at once including the washing machine; the single phase set up didn't give any problems.

if house got 2 airconds (2hp n 1.5hp) with 2 heaters and inverter fridge, do i need to upgrade to 3 phase if want to add 2 more airconds?

My parents Semi-D also come with 3-phase as standard. We have 10 aircons, 3 fridges, 4 water heaters and 1 water pump. Average monthly electricity bill is around RM 900 with 4 aircons and 3 water heaters running at night. The rest are running 24x7.

I heard the contractor said that 3 phase will save more electricity.. is it true?

Nope. 3 phase will lessen the chance of tripping and brownouts only. Contractors will say anything to earn more money.

I installed 3 phase because:

1) i have 3 heaters and 8 aircon points (now only install 7).
2) 3-phase installation cost difference is only rm1K+ only (including TNB charges), so just do it and save the headache later.

But generally u don't need 3 phase if only 4-5 aircons+3 heaters, since nowadays aircons use less electricity already. Go for inverter aircons which reduce current spikes and thus will not exceed the 60A maximum rating for 1 phase.

wahh.. rm900 per month just for electric bill.. u must be very lich.. but i guess most of the electric consumption comes from water pump and air-con is it?

the other advantage i heard is that if your area is blackout your house will still be lighted up as the current will be drawn from another 'line'...

numbertwo,

that totally depends on what phases are hit. my area : rarely one phase or two only hit. most of the times all phases are off. but yes, if only one phase hit (and i have no power) my neighbours are with 3phase are lucky still can do whatever cause they have power. but then again TNB is very quick in fixing issues. hardly ever have outages that exceed 30 minutes and outages are really quite rare these days it seems. maybe 1 tops two per year.

one of the contractor said because 3 phase can load more in one circuit, like a bus, can bring more people at one round compare to the car, so save electricity.......

pening @@

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Added on January 6, 2011, 12:41 pmMy total cost of changing 3-phase..(Not include TNB deposit and contribution) is RM2980, is it expensive?





This post has been edited by edwardsiow: Jan 6 2011, 12:41 PM

true enuf...TNB has surprisingly implemented a few KPIs for their services.. including cutting off my condo's electricity supply within 7 days after the notice! But if I paid the next day at Kedai Tenaga I'm getting back the elec supply by 7PM the same day..lol..super efficient..And I'm talking about similar incidence (means my supply got cutoff twice) happened within 2 mths period.. ...

Not true
If said 3 phase motor is more efficient than single phase motor, then yes, but this is different scope.

It just depended which phase you are on.
Like you living room is on Phase 1,
Room is on phase 2,
Then if TNB supply phase 1 is blackout
Your room still light up.
But definitely your living room will be blackout as well.

Btw, your house electric appliance only can use 1 phase. You cannot use 3 phase electricity with single phase motor for your electrical appliances.
You only tap one of the phase to it only.

Yes, load more, because got 3 wires coming in.

but your total amount of W usage also more.
And TNB charge you based on W.

No one can defy the basic science of electricity law, Watt = Amp x voltage.

Most important understanding about 3 phase even your house is equiped with 3 phase, you only tap one of the phase to your socket, to your light.
You cannot light up with 3 phase.

3 phase is used because 1 phase is not enough for your house total load. As standard voltage is 240v, and with the wire size capability, there is a limit how much the power delivered.
Remember Watt = Amp x voltage (240)
if you use too many electrical appliance, it just mean you need higher Amp, and there is a limit how much the amp can be carried in a wire size, before it overloaded.

whether 3 phase or 1 phase, all consideration is about how much your load is.

Btw, 3 phase comes with 3 wires.
It is just like single phase x 3, just angular issue is different.

This post has been edited by cherroy: Jan 7 2011, 05:37 PM

sorry because of my poor english.
some ppl they may have misunderstand something.
if u using a 2.5hp or more than that air-con, pls choose any 3-phase type air-con,more efficensy n save money.some ppl they though their house is 3-phase,than they go n buy a 2.5hp single-phase air-con will save money,thats wrong. u need to c the eer value, some product if even u install an 1hp + 1.5hp = 2.5hp , the electricity more saving than the 2.5hp 1phase, n if u can ,install an 2.5hp 3phases type u can get the more eer value.
y ppl say that 3 phase wiring is more saving form 1 phase?the waste of energy from wire heat
first ,u have to determine how is the maximum amp of ur house will use?..mostly electric appl will show at behind sticker. add up all.
if a max of 60A , and ur house is wiring with 65A wiring, n sometime u feel the wiring will get a bit warm or hot, that the part thats waste energy, so, use an 100A type wiring will save them.always remember, any part of wiring or switch or mcb,elcb,rcb ,fuse bla bla, that all are warm,hot are adnormal, n wasting energy, the cause was:
1.wrong amp rating,wire, mcb,elcb,fuse bla bla.
2. connector connection not tie enough.
3. short circuit bc of mice bit,moist.

so if a 100A of max how?(is that ur house is a factory?).. apply 3phase to dist them.

every house is 3phase ready(even 100years ago), unless the contractor using only a main wire pull from room1 to roon N. bc most of our nation resident using 3phase for dist current only, but not using 3 phase appliance..

This post has been edited by yi_min82: Jan 23 2011, 12:35 PM

sorry yi_min82, but that makes no sense at all.

Hi Friends, My house is using
1. 4 1hp york air con (6 yrs old)+ 1hp new panasonic + 1 1.5hp new panasonic... total 6 aircon(5 1hp + 1 1.5 hp)
2. 1 fridge
3. 1 Washing Mechine
4. 3 instant water heaters (5 yrs old)
5. 1 PC
6. 1 Laptop
7. 2 LCD tv with dvd
8. 8 ceiling fans + 1 wall fan
9. Kitchen exhausting fan

But my house still using 1 phase wiring. Should I change to 3 phase wiring? Experts please advise...

The efficiency of 3 phase motor is about how 3 phase motor work vs single phase motor, not primary wire heat issue.

Most residential house is not equiped with 3 phase, you need to apply from TNB only then they will pull the wire.

sorry about my language.
wat i mean 3phase in our resident house is not actually with 3phase wiring,it only reach until the Db box. actual 3p wiring for appliances had to have at lease 4 wire (r,s,t,ground),sometime it add 1 more (r,s,t,n,ground),not like 3wire(L,g,n).
eg.acson or york cassette type 4hp.
eg.ceiling type or concealed type
mostly they install at living room.

3phase 4hp, n 1phase 4hp, witch one current using more ?1phase right? so the current flow more n generate heat or lost energy because of resistance. btw,yup, its not primary,but second . so conclosion, 3phase save more with 3phase appliances.

err, maybe you can try post in Mandarin and we try to translate.
Because I don't really understand what you meant. I bet others are also blured with your statement.

What I understand from your post is you're saying most electric appliance doesn't come with 3 pin plug thus it is not meant for 3 phase? Is that what you are saying?

He's talking about electrical appliances that use 3 phase. Usually, industrial / commercial appliances that needs higher voltages/current. The plug looks different from your typical 3 prong plug. It has 4 to 5 prongs. 3 prongs is for each of the 3 phases.

TNB's 3 phase cable reaches your DB box only, from there onwards, electrical appliances inside your house runs only on a single phase.

About the energy loss via resistance, I am not too sure about that. However, I know 3 phase motors uses less energy than comparable single phase ones.

Thanks for the explanation. Much more clearer now.
So can we conclude that it doesn't save as far as the myth of 3-phase wiring is concerned i.e. only reaches the DB box.

This post has been edited by b00n: Jan 24 2011, 10:44 PM