GFI outlet Thermal mystery

[CrystalVoid]

good day everyone!

so the other day I picked up this cool new toy.. the "FLIR one" (loads of fun) and I was looking around my apartment and noticed this..

the GFI outlets in my apartment .. with nothing plugged into them are 10 to 20 degrees Fahrenheit  (+15c ish) warmer then the walls.
I have attached a sample image as well as uploaded it here https://dl.dropboxusercontent.com/u/4185122/grumble/GFIflir.png
is this normal? should I be concerned?
would anyone with a thermal camera mind confirming my findings?

thank you all

[helius]

Do you leave the outlets in the "reset" position? Neon indicator lamps become warm when lit.

[IanB]

I think a GFCI is an active device with an internal power supply and some electronics. If so I would expect it to consume some power while energized.

[CrystalVoid]

I do not think this model has a lamp (none visible) .. however I will trip one and see if it cools down .. maybe there is one inside that's not visible.
thanks

[Chris C]

Interesting.  A quick Google search list examples of GFCI outlets tested to consume power between 2-7W.  I had no idea they consume that much.  Seems your thermal imaging is credible.

Now if you see that kind of temperature rise on an extension cord, or where the plug enters the socket, that's an issue.

[CrystalVoid]

hmm interesting this is after ~2hours of it in the tripped off position   https://goo.gl/photos/TgfFzWq61x1AC6XR8

[Monkeh]

hmm interesting this is after ~2hours of it in the tripped off position   https://goo.gl/photos/TgfFzWq61x1AC6XR8

Output off != circuitry off.

[nbritton]

GFCIs are fairly complex circuits, I believe they even have microcontrollers in them. It would not surprise me if they ran hotter then regular receptacles.

[Monkeh]

GFCIs are fairly complex circuits, I believe they even have microcontrollers in them. It would not surprise me if they ran hotter then regular receptacles.

Uhm, a regular receptacle is nothing but some brass stampings secured in a plastic box, so they don't generate heat at all..

[Zero999]

Interesting.  A quick Google search list examples of GFCI outlets tested to consume power between 2-7W.  I had no idea they consume that much.

That's terrible. It probably wouldn't be allowed in the EU!

Why not just have one breaker where the power enters the property? Having a separate GFCI in each socket seems silly.

[IanB]

Why not just have one breaker where the power enters the property? Having a separate GFCI in each socket seems silly.

Because if that one breaker tripped your whole house would be plunged into darkness. Not to mention your fridge and freezer would stop as well. That would be a terrible idea!

Robust designs should follow the principle of least action. If one circuit develops a fault, isolate the one circuit. Don't cause collateral damage...

[cs.dk]

Why not just have one breaker where the power enters the property? Having a separate GFCI in each socket seems silly.

It done that way in Denmark. I think most of Europe is doing it that way to?

[HackedFridgeMagnet]

In Australia, in new installations we normally have one RCD (GFCI) combined with an overload circuit breaker per sub circuit. So maybe between 5-20 per household.
Dont know what power they consume.

[fubar.gr]

GFCIs are fairly complex circuits, I believe they even have microcontrollers in them. It would not surprise me if they ran hotter then regular receptacles.

This seems to be the case with US spec GFIs.

European ones are entirely electromechanical, no electronic parts inside. Also, they do not consume any power and in theory they can work at very low voltages and even DC.

I just tested an ABB made one, I can trip it using a AA battery.

[Monkeh]

GFCIs are fairly complex circuits, I believe they even have microcontrollers in them. It would not surprise me if they ran hotter then regular receptacles.

This seems to be the case with US spec GFIs.

European ones are entirely electromechanical, no electronic parts inside. Also, they do not consume any power and in theory they can work at very low voltages and even DC.

Errr... no, certainly not all of them..

[SeanB]

Definitely not the newer ones. The older ones used the imbalance current to drive the trip coil, but the new ones use a small capacitive dropper inside to power the single IC that does the work. The capacitor does draw a small amount of reactive current and the electronics run off a low voltage ( capacitor is a 47uF 10V tantalum) rail provided by the 330nF 300VAC capacitor inside.  Teeny little 8 pin IC inside, HML235, with no data available of the part number, but it does detect the imbalance current and provide the drive for the trip coil. The terst button operates a sense input on the IC, not a dedicated sense winding and 47k resistor like the older ones.

[Zero999]

Why not just have one breaker where the power enters the property? Having a separate GFCI in each socket seems silly.

Because if that one breaker tripped your whole house would be plunged into darkness. Not to mention your fridge and freezer would stop as well. That would be a terrible idea!

Robust designs should follow the principle of least action. If one circuit develops a fault, isolate the one circuit. Don't cause collateral damage...

I should have been more clear. I didn't mean one breaker for the whole property but one for each circuit, like how it's done in the UK. The kitchen is on one RCD, the lighting on another and rest of the house on another RCD. It may be more of an inconvenience because lots of appliances are turned off when there's a fault but at least it doesn't result in 2-7W wasted per socket.

[helius]

I should have been more clear. I didn't mean one breaker for the whole property but one for each circuit, like how it's done in the UK. The kitchen is on one RCD, the lighting on another and rest of the house on another RCD. It may be more of an inconvenience because lots of appliances are turned off when there's a fault but at least it doesn't result in 2-7W wasted per socket.

In the US (and I guess in most countries that don't use ring mains) there is one main fuse/breaker for the premises and 20-30 circuit breakers in a panel, each rated for the appliance it feeds. The outlet GFCIs are common, but they don't need to be in every outlet; a single GFCI outlet can protect the entire circuit if it is wired first in line. So I don't see moving the RCDs from outlets to the panel would save much energy.

[dom0]

Well that's interesting now, isn't it?

I never knew until now that there are electronic RCDs for domestic use, I only knew the usual electromechanic RCDs (power usage = 0 Watts). Honestly I'm surprised that people spend that much money on RCDs, the electronic ones I know are all very expensive industrial stuff...

[sunnyhighway]

In the US (and I guess in most countries that don't use ring mains) there is one main fuse/breaker for the premises and 20-30 circuit breakers in a panel, each rated for the appliance it feeds. The outlet GFCIs are common, but they don't need to be in every outlet; a single GFCI outlet can protect the entire circuit if it is wired first in line. So I don't see moving the RCDs from outlets to the panel would save much energy.

But wouldn't that make the line between the circuit breaker panel and the first GFCI outlet unprotected from ground faults?
This looks like playing Russian roulette to me when drilling a hole in the wall.

[Monkeh]

In the US (and I guess in most countries that don't use ring mains) there is one main fuse/breaker for the premises and 20-30 circuit breakers in a panel, each rated for the appliance it feeds. The outlet GFCIs are common, but they don't need to be in every outlet; a single GFCI outlet can protect the entire circuit if it is wired first in line. So I don't see moving the RCDs from outlets to the panel would save much energy.

But wouldn't that make the line between the circuit breaker panel and the first GFCI outlet unprotected from ground faults?
This looks like playing Russian roulette to me when drilling a hole in the wall.

The Americans have little concept of circuit protection like that. They also have no concept of running wires in predictable places, they just string them wherever is convenient in the wall.

[IanB]

The Americans have little concept of circuit protection like that. They also have no concept of running wires in predictable places, they just string them wherever is convenient in the wall.

That depends on whether the lobbyists with vested interests have managed to get to the politicians. In places where they have the regulations require all cables to be installed in metal conduits, for example, and also require arc fault circuit interrupters to be installed at the panel (the stock price of AFCI manufacturers skyrocketed when they got that one on the books).

[Monkeh]

The Americans have little concept of circuit protection like that. They also have no concept of running wires in predictable places, they just string them wherever is convenient in the wall.

That depends on whether the lobbyists with vested interests have managed to get to the politicians. In places where they have the regulations require all cables to be installed in metal conduits, for example, and also require arc fault circuit interrupters to be installed at the panel (the stock price of AFCI manufacturers skyrocketed when they got that one on the books).

Please don't bring politics into this, they have nothing to do with it.

[Troy]

The Americans have little concept of circuit protection like that. They also have no concept of running wires in predictable places, they just string them wherever is convenient in the wall.

"But muh electrical system superiority"
GFCI circuits in the States are often fed from the first receptacle in the circuit, as it is more for protecting the person using an item plugged into that outlet rather than someone bashing a hole in the wall and chewing on the cable.


What the source of heat is likely from is a poor wire splice in the back of that box, or a loose connection.

[Monkeh]

GFCI circuits in the States are often fed from the first receptacle in the circuit, as it is more for protecting the person using an item plugged into that outlet rather than someone bashing a hole in the wall and chewing on the cable.

Thank you for proving my point.

What the source of heat is likely from is a poor wire splice in the back of that box, or a loose connection.

Modern GFCIs, as you call them, actually do produce heat. Some actually hold the contacts closed with a solenoid.