Heat Pump - Dedicated Circuit

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Achh007

10 posts

Wannabe Geek

#3123269 3-Sep-2023 13:36

Daynger:

Achh007:

Thanks so much mate, I was writing a stern email to them before I saw your message.

Appreciate your input and everyone else who has replied - It's been great being on here and amazed with the quality of technical responses.

Actually the technical responses here leave alot to be desired.

While some are accurate, most are kinda sort right and others have bad if not completely wrong.

For me it helped me a lot as at least I have confidence what they did is correct, RCBO was a big one as I always thought it was an RCD (which it states at the bottom)

Also someone suggested to combine 2 lighting MCBS into one and have a dedicated circuit for the heat pump - I am layman here, but my thinking increase the circuit breaker from 10A to say 25A and then combine 2 lighting MCB's into 1 and put a 25A for the heat pump (not sure how doable it is).

Bung

6489 posts

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#3123311 3-Sep-2023 15:07

SomeoneSomewhere: Just realized I did not look closely enough at the picture. That's not (just) an RCD; it's an RCBO, which is a combination RCD and MCB. So all is fine.

What was it originally? Was it an old install that had just 1 RCD (as original label)that's been swapped for an RCBO? I'd be interested in seeing how one of the other units was wired.

Achh007

10 posts

Wannabe Geek

#3123315 3-Sep-2023 15:26

Bung:
SomeoneSomewhere: Just realized I did not look closely enough at the picture. That's not (just) an RCD; it's an RCBO, which is a combination RCD and MCB. So all is fine.

What was it originally? Was it an old install that had just 1 RCD (as original label)that's been swapped for an RCBO? I'd be interested in seeing how one of the other units was wired.

I am not sure, but it was an RCBO before too, the heat pump electrician didn't change anything. We got the house only a few years back so not sure of the history of it.

raytaylor

4017 posts

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#3123384 3-Sep-2023 18:01

Achh007:

someone suggested to combine 2 lighting MCBS into one and have a dedicated circuit for the heat pump - I am layman here, but my thinking increase the circuit breaker from 10A to say 25A and then combine 2 lighting MCB's into 1 and put a 25A for the heat pump (not sure how doable it is).

You cant typically do that because the tps cable used for lighting circuits is typically thinner and only good for ~15 amps so must be protected with a 10 amp breaker.

It would be possible if you didnt have more than a 10 amp load on the two circuits then you could use a single 10 amp breaker. Even so with a limit of 10 amps that is 20x 100 watt light bulbs. Many more if they are LED or compact fluorescent.

But then I wouldnt suggest using an 8 amp appliance such as a heat pump on thinner lighting cable.

Electricians are very risk adverse and never want to risk their trade license in a fire investigation so i think further discussion around it is going to be moot - they did what they saw was the best option for you given the circumstances and it was legal so issued a certificate.

I think its a reminder for the rest of us that it never hurts to run some pvc ducting or extra tps cables in the walls for future appliance needs such as heat pumps or car chargers if we ever have the opportunity.

Ray Taylor

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Achh007

10 posts

Wannabe Geek

#3123398 3-Sep-2023 20:09

raytaylor:

Achh007:

someone suggested to combine 2 lighting MCBS into one and have a dedicated circuit for the heat pump - I am layman here, but my thinking increase the circuit breaker from 10A to say 25A and then combine 2 lighting MCB's into 1 and put a 25A for the heat pump (not sure how doable it is).

You cant typically do that because the tps cable used for lighting circuits is typically thinner and only good for ~15 amps so must be protected with a 10 amp breaker.

It would be possible if you didnt have more than a 10 amp load on the two circuits then you could use a single 10 amp breaker. Even so with a limit of 10 amps that is 20x 100 watt light bulbs. Many more if they are LED or compact fluorescent.

But then I wouldnt suggest using an 8 amp appliance such as a heat pump on thinner lighting cable.

Electricians are very risk adverse and never want to risk their trade license in a fire investigation so i think further discussion around it is going to be moot - they did what they saw was the best option for you given the circumstances and it was legal so issued a certificate.

I think its a reminder for the rest of us that it never hurts to run some pvc ducting or extra tps cables in the walls for future appliance needs such as heat pumps or car chargers if we ever have the opportunity.

Thanks Ray for your helpful advice, I was happy until i saw the COC and hence questioned it as it didn't exactly say the same thing which was done.

This was exactly what it says

It says a 25 amps circuit breaker, while it was installed on an RCD (to me at the time), now I know it's a RCBO but it should mention that.

Do you think this warrants a new COC from them ?

Thanks

rscole86

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#3123401 3-Sep-2023 20:21

This is mine from a few weeks ago.

Install new feed from switchboard including isolator and interconnecting wiring for 3x multi heatpump unit at back side of
house.

I didn't even think to question it, they're the professionals, and as mentioned, it's their livelihood (and liability) on the line.

timmmay

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#3123435 4-Sep-2023 07:53

Achh007:

It says a 25 amps circuit breaker, while it was installed on an RCD (to me at the time), now I know it's a RCBO but it should mention that.

Do you think this warrants a new COC from them ?

No-one is every going to read that COC unless maybe it causes a fire, even then, the question is does that difference matter? If you ask for a new CoC it takes the electricians time for a fairly minor point, they might be less willing to come and help you next time you need help.

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