Incompatible differential!
Solved/Closedbrupala Posted messages 111108 Registration date Status Member Last intervention -
Hello,
I just had an electrical diagnosis done by a diagnostician (I'm selling my house).
He noted an "anomaly":
> B4.3j1 - The rated current of the residual current device placed downstream of the connection circuit breaker is not suitable.
+ note = "connection circuit breaker 60/90A in the presence of a differential device 30Ma set to 63A".
My subscription = 12kVA
My differential = SCHEINER ID'ClicXP - 230V - 30mA - 63A
When I look online > "choosing a circuit breaker for 12 KVA, it says:
In summary, for a 12 KVA connection, a single-phase circuit breaker of 60A of instantaneous or selective type depending on the installation is recommended."
I therefore do not understand why he says it is not suitable?
What do you understand from this detected "anomaly"?
Thank you for your attention.
1 answer
Hello,
This question doesn't belong in this forum; you should have asked it on l'internaute/bricolage/electricity, a sibling forum to CCM. But, based on what you describe, I don't see any problem: a differential switch with a breaking capacity of 63A is suitable behind a supply circuit breaker set to 60A.
In my opinion, the inspector shouldn't have mentioned it, especially since a differential switch cuts off when there's a leakage to ground of more than 30mA, not for a circuit overload, so not at maximum current.
Or maybe the guy doesn't know the difference between a differential circuit breaker and a differential switch, which is concerning for the company that employs him. For example, unlike your subscriber's differential circuit breaker (which belongs to ENEDIS or an equivalent management), it's set to 60A for your 12KVA but typically has a differential of 500mA, meaning it will trip when 60A go through it. Your switch, on the other hand, the 63A indicated is its breaking capacity, not its setting; it will typically trip at lower.
If it were a differential circuit breaker, your Siemens instead of a switch, it should be set to a lower rating than the supply circuit breaker, for example, 20A, but this role is usually given to the circuit breakers at the head of the circuit.
PS,
I checked, the Siemens idclick in question is indeed a differential switch, not a breaker.
By the way, if you have 12KVA, that's starting to be a large domestic installation, you should have several differential switches, not just one? In a new installation, the minimum is two, one A and one AC.
And there you go....
But goodness, the line spacing is so annoying!!