Cooktop replacement- Circuit Breaker upgrade?

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samgdan

160 posts

Master Geek

#312671 7-May-2024 08:28

Hi all,

Calling all electricians....
the kitchen is getting renovated and it got to the stage of the cooktop replacement.
the new cooktop is 6000W.
and from what I can see there is a circuit breaker with a label "Merlin Gerin Multi9 D60 C32 - 240/415 4500"
The current cooktop is 5000W and always worked fine.
from what I can see the oven is using the same circuit breaker as well.

in my view the circuit breaker needs to be replaced as 4500W is below of the current and new cooktop W.
Builder who is doing the renovation said that his electrician confirmed that there is no need to upgrade the wiring or circuit breaker.

can i have second opinions please?
I don't want to engage another electrician at this stage but if it is needed I will.

thank you for your help.

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127 posts

Master Geek

ID Verified

#3227242 7-May-2024 08:35

Not an electrician, but I understand that circuit breakers are there to protect the wiring, not the appliance. IE, stop the wires in your wall from heating up and causing a fire. If the circuit breaker needs upgrading, it likely means the the wiring will also need upgrading and therefore isn't suitable for a 6kw appliance.

In other words, if you don't trust your builders sparky, get your own to give an opinion.

Senecio

2711 posts

Uber Geek

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Lifetime subscriber

#3227251 7-May-2024 09:01

Can't comment on the specifics in your case but I recently had a new induction cooktop installed and the Sparky ran a new circuit breaker from the distribution panel and all new dedicated wiring to the new cooktop. The previous ceramic cooktop and wall oven were on the same breaker and wiring.

For 6,000W I would want dedicated wiring and breaker just for that appliance. I expect your builder is relying on you never needing to run all burners at maximum simultaneously.

samgdan

160 posts

Master Geek

#3227252 7-May-2024 09:06

that was my expectation as well, having everything on (cooktop and stove) in my opinion it will need a wiring or circuit breaker upgrade or run some dedicated wires for the cooktop.

yes most likely we wont have everything on at the same time, however it is a possibility that we need to consider.

jonathan18

7413 posts

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#3227266 7-May-2024 09:47

Yeah, this is the reason why we’ve decided to stick with a reticulated gas hob with our new kitchen, whereas we’d have otherwise chosen to switch to an induction hob - not only would we would needed to have new wiring (from one end of the house to the other) run back to the distribution board, we’ve also run out of space in the distribution board for a new circuit breaker so a new board would have been required. Would have been one expensive change-over…

Spyware

3762 posts

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Lifetime subscriber

#3227280 7-May-2024 11:02

C32 is 32A or 7.2 kW. 4500 is the rated breaking capacity in amps.

Note: Not an electrician.

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samgdan

160 posts

Master Geek

#3227286 7-May-2024 11:23

I have used multiple calculators online and it seems that the Builder electrician is right.

Senecio

2711 posts

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#3227311 7-May-2024 13:10

And if your using the Oven and Cooktop at the same time?

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johno1234

2805 posts

Uber Geek

#3227319 7-May-2024 13:33

Senecio:

And if your using the Oven and Cooktop at the same time?

It would pop the breaker so no big deal?

We used to have a freestanding 90cm range with 4 place induction cooktop. It had a potential current drain that would keep the Huntly power station online but was on the original range's wiring. Never once did pop the breaker as we never had cause to put all the elements on maximum plus oven heating up. And we cook a lot.

timmmay

20580 posts

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#3227390 7-May-2024 15:50

The oven with induction hob we got about 5 years ago was rated higher than our circuit breaker. My neighbor who's an electrician had a practical opinion: if the breaker ever blows let me know and we'll look at what we need to fix. Since the breaker is protecting the wiring at the existing level and we've never tripped the breaker I guess it's fine. If I was putting in a new one that was much higher current I might look at it though.

mkissin

389 posts

Ultimate Geek

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#3227396 7-May-2024 16:11

Circuit breakers have a time component to them. That one is a 32A breaker with a C characteristic curve.

That means it'll give you a 100% over-rate for a full minute before it's guaranteed to pop. That ends up being 15kW for a full minute, which is an alarming amount of energy (enough to raise 2 liters of water from frozen to a full boil).

Daynger

435 posts

Ultimate Geek

#3227483 7-May-2024 19:14

6000W is only 26.whatever Amps.

Circuit breaker is fine, the 4500 is the PSSC rating, not the wattage of what itll run.

Im an electrician.

samgdan

160 posts

Master Geek

#3227562 8-May-2024 08:30

good morning everyone,

thank you for all the replies it seems that the builder electrician is correct. I will let them proceed with the work and see is any issues arise.

cheers.

Zeon

3916 posts

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#3227876 8-May-2024 12:45

Even if it were insufficient whats the chance you have all elements on full power and the oven going at the same time? If the breaker trips in the future do something about it at that time?

The size of the breaker that can be installed will depend on the cross section of the wire in the wall. If its 6mm2 then its a matter of just changing the breaker should it be a problem - 5 minute job.

Speedtest 2019-10-14

Daynger

435 posts

Ultimate Geek

#3228060 8-May-2024 19:32

Zeon:

Even if it were insufficient whats the chance you have all elements on full power and the oven going at the same time? If the breaker trips in the future do something about it at that time?

The size of the breaker that can be installed will depend on the cross section of the wire in the wall. If its 6mm2 then its a matter of just changing the breaker should it be a problem - 5 minute job.

You wont be changing the breaker to a bigger on on 6mm2.

Zeon

3916 posts

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Trusted

#3228241 9-May-2024 10:20

Daynger:

Zeon:

Even if it were insufficient whats the chance you have all elements on full power and the oven going at the same time? If the breaker trips in the future do something about it at that time?

The size of the breaker that can be installed will depend on the cross section of the wire in the wall. If its 6mm2 then its a matter of just changing the breaker should it be a problem - 5 minute job.

You wont be changing the breaker to a bigger on on 6mm2.

6mm2 is allowed for up to 40A in NZ:
https://www.level.org.nz/energy/electrical-design/wiring/wiring-materials/

Speedtest 2019-10-14

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