Wiring in a new cooker circuit

[recom273]

We bought a new oven last week, a Teka HBB 635. We are living in rented accommodation, a pretty basic Thai house, and we need a line to power the cooker from the mains box run as a temporary measure.

 

We called our air condition fitter who has always done a good job for us and people we know, and asked for a recommendation for an electrician, he replied he was an electrician too. He came around to give us a quote today. 
 

I wanted to know what materials he was using, and I said I will go to the wholesalers and pick them up to gauge what he had in mind. We have no existing circuit. 
 

He mumbled about getting back to me on LINE with a shopping list, but he basically inferred he would need a cable, a breaker which he will use as a switch next to the oven and some cable. 
 

The only thing I mentioned was the containment, I don’t need any as we will rip that out when we leave, however I don’t mind spending out on a decent switch / outlet and protection as it may be used again in our new place. 
 

Is that correct? Shouldn’t he install a 32A or 40A MCB in mains box? Or do locals just wire a 6mm cable into the mains box somewhere and rely upon the breaker in the plug? or do I just call a better “electrician”. 

[sometimewoodworker]

2 hours ago, recom273 said:

Is that correct? Shouldn’t he install a 32A or 40A MCB in mains box? Or do locals just wire a 6mm cable into the mains box somewhere and rely upon the breaker in the plug? or do I just call a better “electrician”. 

The information I found was that oven claims to have “Maximum Nominal Power (W): 2615” so 2.5mm cable on a 16A breaker would be enough. You should have an RCCB.

 

If you have different information as to the power requirement please post it.

[recom273]

29 minutes ago, sometimewoodworker said:

The information I found was that oven claims to have “Maximum Nominal Power (W): 2615” so 2.5mm cable on a 16A breaker would be enough. You should have an RCCB.

 

If you have different information as to the power requirement please post it.

Oh, that’s strange - the reason I thought it would need a different main was that the Thai site said 18W which confused me, which is why I thought an electrician would be needed - I showed him the specs today too.

OK .. time to get another electrician if he doesn’t know the difference between 18 and 2615. 

 

[Crossy]

The Teka site is about as useful as a chocolate teapot, it gives 18W as the consumption of the cooling fan, but says zip about the important bit, the heating element.

 

The Shopee detail puts the consumption at 2,300W, about 11A so 2.5mm² on a 16A or 20A breaker would be fine. You could even plug it into a regular 16A Thai outlet, but that wouldn't leave a lot for your microwave, kettle etc.

 

The "manufacturer's instructions" is always the fall back, do they say anything useful?

 

Note: You may find that it trips an RCD/RCBO when new, oven elements are notorious for getting damp and leaky when not used for a while. Provided it's properly grounded you can run it on a regular MCB for a few hours until it's dried out them move it back to the RCBO.

 

[sometimewoodworker]

4 hours ago, Crossy said:

The Teka site is about as useful as a chocolate teapot, it gives 18W as the consumption of the cooling fan, but says zip about the important bit, the heating element.

I think the masters google skills may need a little polishing. ???? Or it was before the morning caffeine kicked in.

[sometimewoodworker]

9 hours ago, recom273 said:

Oh, that’s strange - the reason I thought it would need a different main was that the Thai site said 18W which confused me, which is why I thought an electrician would be needed - I showed him the specs today too.

OK .. time to get another electrician if he doesn’t know the difference between 18 and 2615. 

 

Well no, it’s probably the information that is poor on the Thai Teka site and in the instructions.

 

take a look at the information I posted, if you can see all the numbers from those specifications then yes he is incompetent.

 

but if he can run a standard 2.5mm earthed cable with RCBO for you then it’s all good.

[Crossy]

Teka Thai site ("English" courtesy of Google Translate):- 

 

[sometimewoodworker]

36 minutes ago, Crossy said:

Teka Thai site ("English" courtesy of Google Translate):- 

 

Well it is THAILAND so maybe it’s like many of the cars that only have cabin cooling and no heating, the model sole here only needs the fan!!! ???? or just a crappie job.

 

 

[recom273]

53 minutes ago, Crossy said:

Teka Thai site ("English" courtesy of Google Translate)

 

Thanks, We haven’t received the oven yet, but I spoke to Teka this morning and they (said they) will send a pdf the installation manual 

 

We contacted another electrician recommended by my local electrical wholesaler who is coming to quote tomorrow.

 

You were spot on with the kettle / microwave combo - We have two single powerpoints in the Thai style kitchen, both power kettle / microwave / fridge / fridge freezer/ toaster and washing machine. So a dedicated outlet would be welcome.

This is our existing box, is running a 2.5mm cable from the box to a wall mounted RCBO next to the cooker and wire the oven to that, is this an acceptable solution? I think this is what the first guy was suggesting.
 

 

[sometimewoodworker]

13 minutes ago, recom273 said:

Thanks, We haven’t received the oven yet, but I spoke to Teka this morning and they (said they) will send a pdf the installation manual 

 

We contacted another electrician recommended by my local electrical wholesaler who is coming to quote tomorrow.

 

You were spot on with the kettle / microwave combo - We have two single powerpoints in the Thai style kitchen, both power kettle / microwave / fridge / fridge freezer/ toaster and washing machine. So a dedicated outlet would be welcome.

This is our existing box, is running a 2.5mm cable from the box to a wall mounted RCBO next to the cooker and wire the oven to that, is this an acceptable solution? I think this is what the first guy was suggesting.
 

 

Sounds like an OK plan, if you have a good earth already 

[recom273]

2 minutes ago, sometimewoodworker said:

Sounds like an OK plan, if you have a good earth already 

Do I have a decent earth with this set up?

[sometimewoodworker]

11 minutes ago, recom273 said:

Do I have a decent earth with this set up?

Do you? We have no way of knowing.

[bankruatsteve]

If you can take the cover off your CU, that should give idea what your earth/ground situation is.  The main breaker appears to be RCBO, so if you come from an MCB in the box, you don't need another RCBO at the oven, or any breaker, just direct wire.

[recom273]

20 minutes ago, bankruatsteve said:

If you can take the cover off your CU, that should give idea what your earth/ground situation is.  The main breaker appears to be RCBO, so if you come from an MCB in the box, you don't need another RCBO at the oven, or any breaker, just direct wire.

Great, thanks for the info, TBH, I am not afraid to get stuck in, but I jut want to find a trustworthy electrician and leave it to him, I have a few things on my plate at the mo'. My next door neighbour works as an electrician for Chevron, (he's on rotation at the moment) he is always  a reliable source, but he won't get involved in discussions or have an opinion with Thai electricians.

 

The air-conditioning man / electrician didn't fill me with confidence. it would have been better if he even took the cover off the CU, I'm just a bit confused by the "different" methods here. Lets see what happens tomorrow, I feel better advised now.

[bankruatsteve]

Let's ASSUME the CU has proper earth.  Then, you could just run 3-2.5mm² wires (L,N,E) in surface mount conduit to where your oven will be and install a surface mount duplex receptacle.  That should help out in the kitchen.  Without knowing your breaker situation, the oven L could add on to existing 20a breaker that is not for the kitchen.  

 

If you don't have ground in your box, it WILL be needed to run to, at least, your oven.

[recom273]

53 minutes ago, bankruatsteve said:

Let's ASSUME the CU has proper earth.  Then, you could just run 3-2.5mm² wires (L,N,E) in surface mount conduit to where your oven will be and install a surface mount duplex receptacle.  That should help out in the kitchen.  Without knowing your breaker situation, the oven L could add on to existing 20a breaker that is not for the kitchen.  

 

If you don't have ground in your box, it WILL be needed to run to, at least, your oven.

I can’t see an earth .. 

[Crossy]

The bare copper bar bottom right looks suspiciously earth-like with its green wires, where do the fat black ones go?

 

[sometimewoodworker]

3 hours ago, recom273 said:

I can’t see an earth .. 

 

 

really?

[sometimewoodworker]

4 minutes ago, Crossy said:

The bare copper bar bottom right looks suspiciously earth-like with its green wires, where do the fat black ones go?

 

It looks rather like a MEN link?

[Crossy]

5 minutes ago, sometimewoodworker said:

It looks suspiciously like a MEN link?

 

Strong possibility and the fat black one at the bottom of the bar goes to a rod, maybe.

 

Of course the incoming supply colours are reversed to cause everyone confusion.

 

If it is MEN with a good rod he's pretty good to go.

[recom273]

8 minutes ago, Crossy said:

 

Strong possibility and the fat black one at the bottom of the bar goes to a rod, maybe.

 

 

13 minutes ago, sometimewoodworker said:

really?

Damn .. I had always presumed that was was the incoming power. 

 

Great, so I’m good to go! 
 

Thanks.

[sometimewoodworker]

3 minutes ago, recom273 said:

 

Damn .. I had always presumed that was was the incoming power. 

 

Great, so I’m good to go! 
 

Thanks.

Well, you need to find where the thick black cable goes to. If it goes to an earth spike the you are probably OK as long as the spike is in slightly damp earth not bone dry soil.

[Crossy]

1 minute ago, recom273 said:

Great, so I’m good to go! 

 

Please verify that:-

• One of the fat black wires goes to the top right hand terminal of the big breaker.
• Another fat black is one of the far right pair coming in at the top.
• This far right pair should be your incoming supply, if you can trace where it goes that would verify.

The third black on the bar should go to a rod, again if you can trace it that it would also be handy.

 

Are there any wires on the bottom of the leftmost of the tree breakers? Could be a source for your new circuit.

 

 

[Metropolitian]

I 'inspected' your box and can confirm that there is an earth bar and highly possible an earth rod connected.

Three big black wires, the two on the top are from the mains in and back to the main switch and the bottom fat black is going to an earth point. (can be rod, can be bonded to steel frame of the building I have seen that before). Following the lead will get you to the answer.

 

Sometimewoodworker has 'bluesquared' the earthbusbar in his post.

 

All these 3 breakers are in use, even the leftmost.

Crossy, you can see the black wire if you compare the 'eye' for the mounting screw.

You can use the leftmost breaker, and is also advisable, because the other two are sharing the feed on the top. The link on that between breaker 1 and 2 is used by breaker 2 and 3.

 

Further, my inspection by eye;

 

Have the electricican the from the main breaker to the (american style) RCBO and from the RCBO to the breakers fixed. They are reversed.

 

Do you have another consumer unit or small breakerbox in the vicinity? Where are the wires that come out at the top on the right side going?

They are not from one of the breaker, but from the 'rcbo' directly.

 

One of the wires (the one that comes in on the top on the left side) is disconnected. Do you know where it goes? If it isn't in use anymore, mark it just in case the electrician accidentally re-connect these wires and be unknown about the other side of the line possibly is bare open touching something that you can touch.

 

The earthbusbar is hold by plastic mounts, and I don't see any bonding with the metal case. With wires that can be stuck in the 'door' without protection I would not leave this like that.

 

Do tell us what the man said tomorrow. Let him (or her..) look first before showing your 'list' ????

[recom273]

2 hours ago, Metropolitian said:

I 'inspected' your box and can confirm that there is an earth bar and highly possible an earth rod connected.

Three big black wires, the two on the top are from the mains in and back to the main switch and the bottom fat black is going to an earth point. (can be rod, can be bonded to steel frame of the building I have seen that before). Following the lead will get you to the answer.

 

Sometimewoodworker has 'bluesquared' the earthbusbar in his post.

 

All these 3 breakers are in use, even the leftmost.

Crossy, you can see the black wire if you compare the 'eye' for the mounting screw.

You can use the leftmost breaker, and is also advisable, because the other two are sharing the feed on the top. The link on that between breaker 1 and 2 is used by breaker 2 and 3.

 

Further, my inspection by eye;

 

Have the electricican the from the main breaker to the (american style) RCBO and from the RCBO to the breakers fixed. They are reversed.

 

Do you have another consumer unit or small breakerbox in the vicinity? Where are the wires that come out at the top on the right side going?

They are not from one of the breaker, but from the 'rcbo' directly.

 

One of the wires (the one that comes in on the top on the left side) is disconnected. Do you know where it goes? If it isn't in use anymore, mark it just in case the electrician accidentally re-connect these wires and be unknown about the other side of the line possibly is bare open touching something that you can touch.

 

The earthbusbar is hold by plastic mounts, and I don't see any bonding with the metal case. With wires that can be stuck in the 'door' without protection I would not leave this like that.

 

Do tell us what the man said tomorrow. Let him (or her..) look first before showing your 'list' ????

Great! i really appreciate your attention to detail. 
 

Yes, the story, We have lived here for 10 years, but we hope to be out of here within the next 12 months, all being well. The landlord is a right cowboy, however, the place is just a single row of 6 townhouses on the edge of town, We love living here, when we moved in they were still finishing the house, we pay the same rent as we did 10 years ago, now small potatoes - Landlord doesn’t do any upkeep and no thought was given to future-proofing, so you can see all the breakers are in use.

 

There is another box upstairs which has 2 isolators - one lighting circuit and a water pump line, and which we use for one small AirCon unit. I don’t want to start correcting the landlords wrongs, fingers x we won’t be here much longer and it will be me that pays.

 

i forget what the lose cable is, maybe a 240V doorbell that some other cowboy user to power a water pump in the garden I forget now, it comes from the buzzer on top of the CU.

 

We had an issue the other month where the breakers were tripping out, my next door neighbour identified the issue, everything is so corroded due to the humidity down here. Cables were arcing and so the next day, landlord shows up with this “very good electrician” - who replaced some cables and got busy with the insulating tape. It anything is reversed then this would have probably been him, maybe something didn’t reach.

 

I will see what this guy is saying tomorrow, he appears to be a site electrician, I can give him a little test. 
 

I will send you a PM because I’m confused by a typo 

[Crossy]

Before swapping any wires on the big Hitachi breaker do verify polarity (neon screwdriver).

 

The wiring does appear reversed (colours) but it also appears that there's a MEN link between the top right (black) wire and the earth bar, so that is the incoming neutral.

 

[Metropolitian]

On 2/28/2020 at 5:03 AM, Crossy said:

Before swapping any wires on the big Hitachi breaker do verify polarity (neon screwdriver).

The wiring does appear reversed (colours) but it also appears that there's a MEN link between the top right (black) wire and the earth bar, so that is the incoming neutral.

I am sure the 'electrician' knows what he is doing  and I highly doubt he is here on TVF to read your comment ????

 

The wiring is ok-ok, only the wires coming from the main cables outside is reversed to make up the color for the neutral going to the bus bar.

Should have been the grey/white one that's going to the busbar and then to the main switch. I am pretty sure that outside the grey/white is connected to the life.