My best guess for the extra green sense wire is that it may be there to help avoid false trips due to any external RF interference picked up by the cable. If there is a lot of electrical noise nearby, this can cause currents in the wires that are not actually due to the electrical circuit itself, and that can be picked up by the sense coil and cause some GFCIs to trip when they shouldn't. With the shielded wire, any externally-induced currents in the wire would also show up in the shielding as well. Since the shield wire goes through the sense toroid in the opposite direction to the others, if the same current (in the same direction) is present in both the wire and the shield, they would tend to cancel each other out, and not be detected as strongly by the circuit. This device looks like it was intended for use in possibly electrically noisy environments, where some other types of GFCIs might have problems because of interference, hence the extra shielding and countermeasures against RFI...
@@foogod4237 thanks much for your well-reasoned response. I was pleasantly surprised with the added level of sophistication of the device since I’m sure it was sold as “just a plug strip” … thanks again.
I would say number one, an extra sensor in case cable is damaged. We have GFCI cables at work and it's only three wires inside, like any other power cord.
I think the green wire is the "ground fault" part of the circuit interrupter - in europe its called Residual Current device - that's balancing the flow of the live and neutral conductor; but i see in the american GFCI - its also got a ground element.. cool! thank you
No, in the US these are called "ground fault" interruptors, but the circuit itself does not have anything to do with the ground wire (in most GFCIs, the ground wire is not even connected to the circuit, and will function just fine even if there is no ground present at all). As described in this video, GFCIs only look at the current flowing on the hot line and the neutral, and will trip any time those two things are not balanced in some way.
My best guess for the extra green sense wire is that it may be there to help avoid false trips due to any external RF interference picked up by the cable. If there is a lot of electrical noise nearby, this can cause currents in the wires that are not actually due to the electrical circuit itself, and that can be picked up by the sense coil and cause some GFCIs to trip when they shouldn't. With the shielded wire, any externally-induced currents in the wire would also show up in the shielding as well. Since the shield wire goes through the sense toroid in the opposite direction to the others, if the same current (in the same direction) is present in both the wire and the shield, they would tend to cancel each other out, and not be detected as strongly by the circuit.
This device looks like it was intended for use in possibly electrically noisy environments, where some other types of GFCIs might have problems because of interference, hence the extra shielding and countermeasures against RFI...
@@foogod4237 thanks much for your well-reasoned response. I was pleasantly surprised with the added level of sophistication of the device since I’m sure it was sold as “just a plug strip” … thanks again.
Pretty sure it prevents false trips, cause obviously we have GFCI outlets that don't require shielded wire.
@@CurtusVanPebbles well reasoned … thanks for your comment!
I would say number one, an extra sensor in case cable is damaged.
We have GFCI cables at work and it's only three wires inside, like any other power cord.
@@ralanham76 thanks for your reply and for subscribing !
The toroidal current transformer is made of ferrite, a polycrystalline material made of iron. Carbon would not work as it is non-magnetic.
@@BritishBeachcomber thanks for the clarification.
Ferrite doesn't make sense at 50/60 Hz. Current transformers usually have nickel cores.
The black stuff was probably a black plastic housing.
I think the green wire is the "ground fault" part of the circuit interrupter - in europe its called Residual Current device - that's balancing the flow of the live and neutral conductor; but i see in the american GFCI - its also got a ground element.. cool! thank you
Thanks for your comment
No, in the US these are called "ground fault" interruptors, but the circuit itself does not have anything to do with the ground wire (in most GFCIs, the ground wire is not even connected to the circuit, and will function just fine even if there is no ground present at all). As described in this video, GFCIs only look at the current flowing on the hot line and the neutral, and will trip any time those two things are not balanced in some way.