RANT: Those new Arc Fault Circuit Breakers!!!

[james_s]

I do like the DIN rail design rather than proprietary mounting used in North American panels. I don't like how cramped the European panels are though, ours are physically much larger so there's a lot more space to route wires and work around. It's a problem even in the US that a lot of panels are filled on the day they are installed making it a much bigger task to add anything later. It would be nice if they required 25% empty capacity when installed.

[soldar]

I do like the DIN rail design rather than proprietary mounting used in North American panels. I don't like how cramped the European panels are though, ours are physically much larger so there's a lot more space to route wires and work around.

I agree with you but there are reasons. I really like how in America you have hollow walls which make it easy to pass wires and plenty of space for big breaker panels in the basement. It makes work so much easier.

In Spain walls are brick and there is no way to pass new wires, which is a pain. Also, the panel is usually located in a wall behind the front door and you want to hide it as much as possible. It is sunk in the wall which means it has to be built-in during construction. Any changes mean major construction remodeling and a PITA.

Also wall boxes for switches and outlets are too small and a PITA to wire, especially with rigid wire and that is why they allow stranded  cable.

For working the American system is much more convenient but buildings here are what they are.

[nctnico]

I do like the DIN rail design rather than proprietary mounting used in North American panels. I don't like how cramped the European panels are though,

Those pictures are not how all distribution panels in Europe are constructed. In the NL (for example) a typical panel is way less cramped.

[soldar]

John Ward discusses Types of Earthing Systems

[Monkeh]

I do like the DIN rail design rather than proprietary mounting used in North American panels. I don't like how cramped the European panels are though, ours are physically much larger so there's a lot more space to route wires and work around. It's a problem even in the US that a lot of panels are filled on the day they are installed making it a much bigger task to add anything later. It would be nice if they required 25% empty capacity when installed.

Unfortunately due to a large amount of older buildings and manufacturers designing themselves into a corner, we mostly get stuck with somewhat cramped units, at least in the UK.

[soldar]

Oh, I forgot one more thing that I really dislike about Spanish code and that is that, probably for historical reasons which make no sense today, circuits are divided into two categories, "lighting" and "power". Lighting may have a lower amp limit, I am not sure, but they do not have to have protective earth whereas power circuits do. I find that stupid and inconvenient. For example, I have my desktop computer right next to an outlet I cannot use because it has no earth and I need to run an extension cord to another outlet half way around the room. Really stupid. I mean, they saved a few euros.

I have thought about wiring the earth cable but the conduits are so tiny and tight that it is almost impossible to get the third cable through. Short term stupid thinking. 

[james_s]

That is a bit strange, here any light fixture that has metal parts is supposed to be earth grounded to prevent any external parts from ever becoming live. Oddly though this does not apply to portable lamps which almost never have grounded cords. I suspect there are odd quirks like this in the code of almost anywhere in the world. I do like that there are still significant differences from one place to another though, it keeps things interesting. In the era of globalization so many of the goods we get are virtually identical no matter where in the world you buy them.

[Urs42]

This is how it looks in Switzerland. The blue things next to the breakers allow to disconnect the neutral, this is used for insulation measurements. You actually get about 500 USD from the building insurance when you install a surge protector. I've never seen a AFCI here. The last picture is the old panel that was in the house before.

[rsjsouza]

Oh, I forgot one more thing that I really dislike about Spanish code and that is that, probably for historical reasons which make no sense today, circuits are divided into two categories, "lighting" and "power". Lighting may have a lower amp limit, I am not sure, but they do not have to have protective earth whereas power circuits do. I find that stupid and inconvenient. For example, I have my desktop computer right next to an outlet I cannot use because it has no earth and I need to run an extension cord to another outlet half way around the room. Really stupid. I mean, they saved a few euros.

I have thought about wiring the earth cable but the conduits are so tiny and tight that it is almost impossible to get the third cable through. Short term stupid thinking. 

A similar regulation exists in Brasil, but since 1994 protective ground is mandatory for all circuits.

I guess the difference is that in Brasil's code, the illumination circuits cannot have outlets - everything you can manually plug into is considered a "power" circuit.

I personally love this separation, especially considering the way my 1981 house in the US is wired - a circuit contains an absolutely illogical combination of outlets and lights, some even upstairs/downstairs!

[Urs42]

A similar regulation exists in Brasil, but since 1994 protective ground is mandatory for all circuits.

I guess the difference is that in Brasil's code, the illumination circuits cannot have outlets - everything you can manually plug into is considered a "power" circuit.

In Switzerland it is allowed to mix illumination with power and most light switches do also have a power outlet. The code requires that protective ground for outlets is not looped trough lamps. This rule is there to prevent people from disconnecting protective ground from outlets when thy change the lamp.

[orion242]

too small and a PITA to wire, especially with rigid wire and that is why they allow stranded  cable.

That's got to be a good part of why our panels are so much larger.  Trying to run standard 2/0 AWG conductors for a 200A service in from the back of the panel and bending 90 degrees into the breaker simply wouldn't happen in that space.  Even in a US panel coming in the back and wrangling around can be a challenge.

[james_s]

I remember when I wired up my hot tub, 50A circuit with 6AWG wire making that tidy was like trying to tie a knot in a crowbar.

[Electro Detective]

A mains board is 'tidy enough' if you can easily encourage any wire to fit in the jaws of an average size clamp meter, and then pushed back into it's place 

Otherwise tight eye candy 'tidy' is a PITA to troubleshoot, service, upgrade or swap out clapped breakers. 

[IDEngineer]

It's possible to make them tidy AND leave sufficient slack to do real work later. I generally run incoming wires along one full side of the breaker box, then loop back and connect to the breaker.

Some of the "professional" electricians I've seen, though, apparently get bonus points for making breaker boxes the biggest rat's nest possible. There have been a few times where I've been pulling out old romex and I have no idea how they could have ever routed it in there in the first place, it's so wound and interleaved with other romex runs - and each wire in the romex takes a DIFFERENT path through DIFFERENT wires. I swear they get almost 100% visual occlusion of the rear of the box. 

[Gregg]

Would an arc fault breaker have stopped this? It was a Liebert UPS that suddenly became smoke and scrap. 

[james_s]

At least with North American panels, tidy is the difference between a professional job and an amateur hack. Make it nice and clean and the inspector is a lot more likely to sign off and not go looking for minor technicalities. Also if done right it's easy to work on later.

Same goes for receptacles. You're supposed to have 6" of wire from the entry point in the box, with the outer sheath stripped off to within 1" of the entry. You can spot an amateur job instantly by excess sheath left on the wires which are usually then cut off way too short.

[Electro Detective]

I checked out John Ward's great Youtube trilogy on Arc Fault Detection Devices   
(quote JW: 'Arc Fault Deception Devices'  )

and there is no way I would have a 3 way 'all in one' combo wasting 3 Din rail spaces,
eventually nuisance tripping, or not at all, once the unit ages a bit and or exposed to hot/cold/dust/moisture snafus

If they become compulsory here, I'll opt for a larger main board or addon if necessary with separate module AFDDs or AFCDs,
so I can test and get them swapped out if they are duds/placebos,
and leave the working MCB and RCDs or RCBO combos alone to do their job. 

..and save serious dollars not having to pay out on clapped 3 space 'three in ones'   

[Red Squirrel]

Would an arc fault breaker have stopped this? It was a Liebert UPS that suddenly became smoke and scrap. 

I don't know if an AFCI would stop that from happening, but a smoke detector would probably let you know that it's happening. 
 

[Gregg]

I don't know if an AFCI would stop that from happening, but a smoke detector would probably let you know that it's happening. 

The UPS blew up in the middle of the night and nobody witnessed the actual event, but the fire department arrived big time.   The fire alarms and detectors worked.  It was in a high rise building in downtown San Jose, Calif.  The feed breaker to the unit did trip like it was supposed to do.  It was 480V 3 phase in and 208V 3 phase out I believe it was 25KVA.  It was a typical crappy Liebert brand that was replaced with a Mitsubishi.

[james_s]

The company I used to work for had a big UPS that blew up at least twice, once it filled the whole floor with stinky smoke while we were there, another time it went off over the weekend and the fire department and facilities manager showed up. I think they finally replaced it completely after that second instance.