Fuse Box Tripping

[nattydread]

my tilacs has a problem at her mum and dads house............the fuse box keeps tripping out when using the washing machine.........it seems to happen more at night time than during the day.......

the fusebox in the pic seems to have a rating of 25 A but the electrician says the problem is because the house only has a 5 amp supply from the power company and they need to pay 700 baht to get it uprated to 15 amps

here is a link to a previous thread i did when the machine was bought and fitted..........they have been washing clothes even though the box can trip out 2 or 3 times during the wash cycle............it also happens if the new microwave and electric kettle are used at the same time

http://www.thaivisa....ashing-machine/

is what the electrician saying about upgrading the supply to 15A correct?

i realise the starter and fuse box need replacing as they are 30 years old...........she tells me that a couple of years ago she paid to have all the wiring and plug sockets in the house renewed back to the fuse box at a cost of 10,000 baht.............what would be the cost of fitting a modern safe t cut device, something like in the pic

sorry i cant give more info.............any help gratefully received.....thanks

Edited August 20, 2010 by nattydread

[bankruatsteve]

If you look at many other threads in this forum, you will see that the meters in LOS are nominally rated and who knows what they supply at max. (?) So, I doubt the meter is the issue in your case. From the photo, the main cutoff on the right most likely is fused (like with little strips of copper). Is that the one rated for 25a? I doubt that is the one "tripping" b/c fuses don't trip - they actually burn thru and you have to replace. So the thingy on the left must be some type of breaker? What is that rated? It looks like you have 5-6 "circuits" going out - are they all going through the same breaker? That might be your problem.

Washers can drraw up to 10a during the water heating cycle and when they DO, if anything else is going on - a 10a breaker will trip from overload.

So, if that's the case, you can just get a breaker box and put MCB's on each circuit - sized to the wire being used (10a for 1.5mm2 and 20a for 2.5mm2). ie: put those wires going out each on it's own proper sized breaker and your tripping prolems should go away. And, of course, they should be RCD breakers.

And, your washer should be on a 20a using 2.5mm2 wire. If it's not, replace.

Edited August 20, 2010 by bankruatsteve

[lopburi3]

Yes the home service should be changed to 15 amp meter (which is normally set to feed main breaker at 62 amps). The 5 amp meter dates from homes with only lights and perhaps a small refrigerator and fan days. The Safe-T-Cut should also be installed and if budget allows change to 3 wire with ground for home to provide more protection. Washer/microwave/refrigerators normally require grounding so best to have it as part of the electric system.

I expect the previous job was very much over priced as such work should not cost anything close to 10k for one breaker and a few wires. You currently have a fuse (old requirement for incoming line) and a 25 amp switch/breaker which is normally used with air conditioners (which must be what is blowing).

The inside work/material I would not expect to cost more than about 10k but you will probably have to replace the pole to home feed wire.

[nattydread]

Yes the home service should be changed to 15 amp meter (which is normally set to feed main breaker at 62 amps).

the supply is being uprated to 15 amp..............today i went into homepro in chiang mai and was confronted with 2 choices

the simpler looking of the 2 boxes...(special c) in pic is rated at 63 amps and costs 3684 baht

the other box looks more like whats required with 6 MCBs in the box.............32A x2...........20A x 2...........16A.............10A................even if a few need changing they are only 110 baht each

the box is supplied in 32A.......45A...........50A.........63A..............unfortunately homepro only have it in the 50A........( 4250 baht).

should i try to get a 63A version of this box?.............or will the 50A be sufficient.................or just get the cheaper box?

there is a thai "electrician" doing the work but he wants to fit a secondhand box but i prefer to buy a new one

thanks again for any advice........the DIY forum is excellent

the thai electrician has removed the contraption with the red starter switch which has cured the electric cutting out 5555555....but i doubt its very safe at the moment so ive told the family to be vigilant and careful until the safe t cut box gets fitted

Edited August 25, 2010 by nattydread

[nattydread]

just to add..............the house has no air con..........no electric oven or shower

they have washing machine..microwave....fridge....fans...computer...tvs

[bankruatsteve]

In my opinion and with what you have described, you really don't need the 15a meter. You just need a decent CU. The Safe-T-Cuts are nice units but again probably something you don't really need. I would just get a Sneider CU with a main breaker of 32a and 4 slots for the stuff: use 2 20a breakers for the socket circuits (assume you have those on 2.5mm2) and the other two on 10a for the fans, lighting, etc. Use the RCBO breaker if you want the protection. That should come in under 3k baht. ie: you don't have to buy something that's already fitted with certain size breakers. Buy an empty CU and fit with what you need. The local sparky should not have any problem hooking it up.

[powderpuff]

On the contrary - a Safe-T-Cut is the single most important device you can buy & install.

It has saved countless lives in Thailand where lots of wiring is dodgy.

Lopburi was trying to tell you to upgrade to the new normal 15/45.

You currently have 5/15.

A 32 amp load center is plenty.

50 amp? Yes very suitable.

That brown thing is a motor starter - used to be used on air cons A LOT.

[powderpuff]

[electau]

Max demand 32A. Upgrade the metering to 15/45A. 45A is the max continuous rating of the meter.

Consumers mains minimum, 10sqmm PVC/PVC twin or 2 x 10sqmm PVC/PVC single core cables.

32A RCBO as the main switch.

A minimum of 3 circuits, 1 x10A lighting and 2 x 20A for socket outlets. All socket outlets to be earthed.

[lopburi3]

The 50 amp load center should be fine and will provide room for expansion if you install water heater later/rewire. Strongly advise having GFI protection (Safe-T-Cut or other such device) regardless of grounding as this protects in extremely short time compared to normal breakers (not to mention ungrounded issues) and does save lives.

[nattydread]

special thanks to Lopburi and Powderpuff and also to other contributors.....i have the information i need now to get the job done

[nattydread]

just a point of interest.............the safe t cut box with the 6 mcbs was priced at 4200 baht in Homepro in CM.............i found the same box and had a choice of fuse sizes to go in it for 2800 baht in a small electrical shop near the moat..........its definitely worth avoiding purchasing anything at homepro if u can find it elsewhere