Arc fault detection

[Marvo]

I have a spec that I'm struggling to meet and wondered if anyone had any ideas. I have a panel with a 32A 3-phase +N incoming supply that supplies four 20A single phase circuits (radials). One of the circuits will be under a constant 12A load and the other three circuits will be under intermittent 16A loads. The entire panel and its circuits requires arc fault interrupt protection.

I've only supplied one panel in the past that required this and it was a 110v 60Hz panel, I didn't have too much problem finding suitable hardware but there doesn't seem to be much available in UK/EU voltage and freq.

Any suggestions gratefully received.

 

[Chr!s]

Abb have a range, I have the design guide somewhere ill see if I can find a link

 

[Marvo]

Would be much appreciated. Thanks Chr!s.

 

[Bobster]

Combination Arc-fault Circuit Interrupters - Combination Arc-fault Circuit Interrupters - Products overview - Schneider Electric United States

This the type of thing your after?

 

[Bobster]

Sorry read through their catalogue, only seem to do 120v models.

 

[Marvo]

Yeah, unfortunately that's the problem I've had. In the US it's mandatory by regs to install arc fault interrupters on certain circuits so the products are obviously market driven and mostly available in 110v 60hz only. Thanks for the info all the same.

 

[gnuuser]

this might help
ARCON Arc Fault Protection System - Eaton Europe - Circuit Protection

Eaton - ARCON®: Extremely fast, extremely reliable

 

[Bobster]

Not having ever used something like this, just spent 10min having a scan over how they work.

I can' see any difference between that and an rcbo?

 

[Marvo]

Thanks GNU, we've used the optical detection quenching unit before in switchgear panels but this is a much smaller system and we only need disconnection, not rapid quench.

Also do you know anything that might provide series and parallel arc fault disconnect protection for the 4 radial circuits?

 

[Marvo]

Not having ever used something like this, just spent 10min having a scan over how they work.

I can' see any difference between that and an rcbo?

They kinda look like an RCD and you do get RCD and AFCI (arc-fault circuit interruption) combination circuit breakers.AFCI's primarily protect against arcing faults which wouldn't be detected by an RCD because there's no earth leakage current.

*Edit* Here's some basic info on how they work.

 

[Bobster]

True but the magnetic characteristics of an rcbo will detect a s/c or is it just more sensitive? I'll have a proper read when I get some time.

I have however used the UV detecting arc protection in bus bar systems, I'd have had no problem recommending a system like that.

 

[Marvo]

Here's a better resource.

 

[gnuuser]

Thanks GNU, we've used the optical detection quenching unit before in switchgear panels but this is a much smaller system and we only need disconnection, not rapid quench.

Also do you know anything that might provide series and parallel arc fault disconnect protection for the 4 radial circuits?

i have installed a few of these
these type are used in split phase radials
i dont have a lot of info on them aside from the link but i do know they are extremely sensitive
https://www.google.com/search?q=afc...ndymanwire.com%2Farticles%2FAFCI.html;479;470

 

[Knobhead]

I’m sorry, this sounds like a solution to a problem that doesn’t exist. If transient over voltage is the problem then a couple of Transorbs back to back sorts that out.

What are the 16A loads to require such protection? I’m used to switching large inductive loads never had a problem.

Like RoB I’ve only used arc detection on intake 11KV boards to kill the 33KV incomers.

 

[Marvo]

Yeah, I've actually written this tender off, there's nobody in my country can provide the required certification so it's way too much headaches. The three circuits were for small positive displacement pumps the smaller circuit was for a concentrate (titration) transducer module, the whole panel was for a special dosing system but the spec was basically aviation standards. The arc protection wasn't about transient over-voltage it was just about monitoring the integrity of the panel and circuits.

 

[Engineer54]

i have installed a few of these
these type are used in split phase radials
i dont have a lot of info on them aside from the link but i do know they are extremely sensitive
https://www.google.com/search?q=afc...ndymanwire.com%2Farticles%2FAFCI.html;479;470

Spoken to quite a few American Engineers about those Arc Fault Detection breakers, and to be honest they didn't think too much on them. I got the impression that they were more trouble than they were worth. Expensive too, i'm led to believe?

 

[gnuuser]

Spoken to quite a few American Engineers about those Arc Fault Detection breakers, and to be honest they didn't think too much on them. I got the impression that they were more trouble than they were worth. Expensive too, i'm led to believe?

yes we dont really care for them too much either
last one i installed was for a 15 amp residential circuit and it cost about $55 (on sale).
customer wasn't too pleased about that but we had to follow what the inspector said