Question on wiring diagram for Pro 4PM with 1P+N

[PMG]

Regarding the wiring diagram where all appliances are protected with 1P+N breakers:

If the leftmost breaker (40A) is also 1P+N, then:

1. should the N input of the Pro 4PM connect to the 40A breaker N output?
2. should the N input to the appliance breakers connect to the 40A breaker N output?

FYI: I'm not connecting any switches to the Pro 4PM; my goal for this Pro 4PM is to monitor power usage of specific kitchen circuits (dishwasher, fridge, microwave oven and kitchen exhaust fan) directly on the switchboard; snubbers have been fitted to the wall outlets.  

Dumb question: wasn't able to understand what LSS means in the diagram? Equipment brand? If so, for curiosity, I have full Hager kit on my switchboard.

[thgoebel]

Please wire the devices as following:

LSS is the German abbreviation of „Leitungsschutzschalter“ which means Automatic Cut-Out.

[PMG]

Will do, thank you!

[G_MAN_be]

Hi @thgoebel

I am confuse by this diagram, and a bit scared because I have always thought the 4PM can only be behind a single circuit. Therefore I have designed all my plans around this concept. (When I started my project, I was not aware of this forum, and these diagrams were not available).

So I use the 4PM only for lights because they are low power, and only 1PM for electricity plugs. In some rare occasions, I have also used 2PM for plugs, but always behind the same 16A circuit breaker.

Here is the diagram I am working on:

Is this a wrong concept if I put everything behind the 10 Amp circuit breaker?

Thanks!

[thgoebel]

A quick comparison between the two diagrams shows that both are almost identical: Only the 40A circuit breaker vs. the one 10A breaker (in your diagram) is different.

The diagram with the upstream 40A breaker is a representation of the manufacturers specs: The Shelly device can control 16A loads, but not more than 40A in total. Hence, upstream and downstream CBs are necessary. I did add the usage of a two pole 40A upstream breaker only. Question was, how the neutral wire had to be wired.

Conclusion: You‘re absolutely right with your wiring with ONE 10A CB upstream! But for scenarios with heavier loads, the wiring with two CB levels is adequate.

[G_MAN_be]

Thank you so much for the info and very fast reply! 🙂

When you say heavier load, you mean load bigger than the total load of the Shelly device right? Here it's 40A, but in the case of 2PM, it would be 25A, therefore if I have only 1 CB upstream of 16A, it would be correct as well?

Sorry if I mix questions about 2PM here, if required, I can ask this question in the 2PM category. 

In any case, thanks a lot for the help! 👏

Edited December 18, 2024 by G_MAN_be

[thgoebel]

Your statement is right considering the Shelly pro 2PM. You may affirm this by reading the specs in the knowledge base:

https://kb.shelly.cloud/knowledge-base/shelly-pro-2pm