Just on the aircon alone, 1hp = 4 amps, 1.5hp = 5.2amps, 2.5hp = 11.5a,amps
Total = 20.7 Amps

Now imagine a small party in your house all aircons running and someone taking a
hot water shower.

Add Bath Water heater (hottest)= 24amps, kitchen load rice cooker = 10 amps, fridge = 5 amps, microwave, water kettle=10amps microwave - 10 amps
Total = 59amps

Add lights/fans and miscellaneous TV, sockets total another 10amps

Grand Total = 90.7 amps. Almost no more safety factor.

Prefer 20% safety factor for transient overloads and copper wiring aging.

Add another phase to balance the electrical load is good advice.

Refer Joven instant water heater http://www.joven-electric.com/product_deta...d=2&series_id=8 specifications.

On highest (hotest) setting it(instant water heater) will draw 20+ amps from your supply. I have confirmed this with a tong tester.

Also don't take the best case scenario that they are using new expensive low power high efficiency energy saving electrical appliances after one(1) year usage any 2kw/3kw rice cooker/kettle will draw near 10 Amps from your mains.

Its looks to be 3 phase but need a multimeter to confirm. If you get 3 phase voltage (415V) between the 2 incomer wires confirm 3 phase wiring. If you measure 240V between the 2 incomer then its single phase.

I'll describe your DB, the top most copper terminal block is the Neutral terminal block. you have 2 Neutral terminal blocks (one at the top and one more btm denoted by the black wires) so logically means a three phase wiring.

The 1st row of circuit breakers is two single pole 63A fuse carriers with associated 2Pole ELCB next to them. Your wireman arrange them one on left and one on right. It's not the usual practice to wire up a DB. I would wire each phase wire to a separate row with double pole (L+N isolated) isolator then to ELCB and then to mcb's.

The DB looks a bit messy with wires not fully terminated. Looks like a job in progress.

If the wiring is new and good insulation no need change wiring ..

just pull the new wiring and balance the load equally among all phases at the DB..

Let me count for us all,

1,3,4 & Autogate = 20A SP mcb x 6 nos.
2 & 6. total 35 fans & lights = 10A SP mcb x 4 nos
5 & 7. = 41 points 13A socket = 20A SP mcb x 5 nos ring circuit

Total = 15 nos SP mcb..

I would do an 18 way SPN DB if there is no more future extensions for the next 20 years.. Then rewire again..

But RM13k .. You must have a big house..

Better get a separate competent wireman to quote (better 3 separate quotes) ..

Never... You pay a bit less than 3 times more..

Its actually the same as 3 single phases, you only use it if your max demand load is higher than the kWH fuse rating (60A) ..

We balance your single phase load by the 3 phases..

Thus if you are maxing out your 60A single phase fuse say you using 90A (easy calc)..

then we divide 90A/3 = 30A so you are not overloading your cables and burning up your cables..

crystal??

Don't worry about it.. He's not saving $$$..

Know your basic facts.. Its good enough.. and I've been a wireman for a really long time..

5 year old wiring is considered new.. 5 year old house I don't know,

i would need to bring my insulation tester, test your wiring, charge you, get paid and then I can tell you..

bro.. say you switch on all the lights in your home..

Now switch on all the aircons in your house..

Now go boil some water and also use the rice cooker.. Pop some popcorn in the microwave on high..

Switch on all your TV's, hifi on full and connect all your sockets chargers, and get your maid to start ironing your clothes..

Make sure all those are on then go and take a hot shower.. using the instant hot water heater

That's the max power you can use for single phase.. also known maximum demand..

Short ans: Look at your DB incoming mcb ampere rating.. Power = Volts I (amps) x pf => 240x40x0.8/1000 kW => 7.68kW(on a 40A single phase DB)


If that doesn't trip your DB after you finish your shower then..

Yes.. you can switch on 1x 2.5hp aircon + 1.5hp aircon at the same time together with heater pump and oven

This post has been edited by Richard: Jun 18 2016, 11:07 PM

False..

Single phase will be always cheaper than three phase.. less cables, devices and complexities

The only reason you upgrade from single phase is if your max demand is higher than the single phase rating and
you are using equipment that requires three phase supply eg. three phase motors..


This statement is also false... Please get your information from the insurance company you are insured with..

Note **kengyan is not a technical educated person.. His post on technical issues are either vague, argumentative and mostly just wrong..

This post has been edited by Richard: Jun 19 2016, 12:32 PM

bro.. not trying too hard are you?

This is a good reference. Read it, understand it, refer to the issue at hand and then make an intelligent response..

bro.. please grow up..

You address the issue, debate it, find the solution and accept the consequences.. How is attacking the messenger going to solve anything?

You are an active part of this forum, be true and accurate to contribute.. Stop acting like a child..

For the sake of discussion if you balance the load equally that's just 2 numbers 2HP (roughly 2 x 7 Amps(running)) air conditioners on at a time..

just don't let all of them start up the same time because of the high starting current ..

In the interest of safety get a competent wire man to check and do your wiring.. Tell him to check and balance the electrical load ..

Ideally the load is balanced across all 3 phases then there is no unbalanced current running in the neutral..

Thus all motors shall be 3 phases, as a single phase motor requires a start (to generate a phase shift for starting torque) and run (to maintain that phase shift) capacitor..

If the system has single phase loads then to balanced each motor loads across the 3 phases..

Each single phase aircon on separate phase..

What you are asking cannot be answered without first checking the type, size and condition of your existing electrical wiring..

The simple answer would be to size the required copper conductor to your maximum demand but that is dangerous without knowing the existing load and condition of that circuit..

Please get a competent electrician to check the condition of your existing house wiring..

The electrician will carry a minimum of two measurement tools..

One is a clamp on ammeter to measure amperage and the other should be an insulation tester..

He will see your existing distribution board measure out the load and test the insulation..

Only after that will you get a qualified answer..

Hope that helps..

If this is all single HP ac units you should have at least 60A cut out fuse with the distribution board and all circuits wired to electrical regulations..

This means all the ac shall have separate individual circuits (20A SP) and wires(2.5mm-4mm) to size..

If you have a large fridge (compressor) then you will need a separate circuit for those as well..

Kitchen electrical circuits are never shared quite simply because of the heavy loads they carry and they have to be terminated properly ..

Periodical testing is also a recommendation..

If you are really doing this please get a quotation from a competent electrician..

It's free and it's the simplest safest way ..

I have the same arrangement.. Its actually an aircon point and I added a few more 13A power sockets..

What's your monthly kWH usage ? 300 above or ..

All the time you use lay man terms..

You don't know better to keep quiet then to keep showing how ignorant you are..

Say something technical please..

Its a bit expensive..

- He wanted to replace the old cutout fuse (next to the Tenaga KWH meter) and Neutral link just because its old. I would too ( Those are rm30 (60A HRC fuse & fuse holder, rm5 for the Neutral link)
(15min job)

- Assuming he wanted to replace the rm30, 40A RCD (Maxguard) to match the load of the 60A DP Isolator (maxguard), (another 10min job)
Both components comply to the IEC regulation but thermal overload trip do not match each other..

Maxguard is a known electrical brand, its competitive and it has SIRIM/ST approval.. It has a presence in our local Malaysian market..

Those are just unscrew, component replacement and tighten back connections..

You can get another quotation if you want.. (A more reasonable rate would be around rm200)..