GFI trip hot tub

[kwired]

i guess ive been confused how gfci works , i thought it measured the conductors seperately they must be equal in the hot lines or the difference will be in the neutral. according to what I see if you put a clamp on meter on all the hot and neutral comming in together it should cancell the current and read zero unless there is a leak thats not returning. I still dont understand what all the other wires are doing in the doenut hole , There are a lot more wires than the 3 lead in conductors.

any current passing through the CT on one conductor must again pass through on a return conductor or the CT will read current and operate the trip device. does not really matter what they go to to some extent.

 

[hurk27]

Here is a link to a very descriptive web page on how a GFCI works:

How A GFCI WORKS

the only difference with a 2-pole breaker is the added hot also goes through the two coils, and there is an added contact that disconnects both hots and neutral, but the function is the same.

 

[LarryFine]

I still dont understand what all the other wires are doing in the doenut hole , There are a lot more wires than the 3 lead in conductors.

They're probably just separate loads switched ahead of the GFCI, like a pair for the heater, a pair for the main pump, maybe a pair for a lighting transformer, etc.

 

[kwired]

They're probably just separate loads switched ahead of the GFCI, like a pair for the heater, a pair for the main pump, maybe a pair for a lighting transformer, etc.

I was thinking same thing but not switched ahead of the GFCI. That would leave non GFCI protected conductors running within the unit. But they would double the current seen by the CT since the supply conductors also carry the same current through the CT. It would make it easier to detect a low level fault with an increased amount of current flowing through the detection component.

 

[hurk27]

I was thinking same thing but not switched ahead of the GFCI. That would leave non GFCI protected conductors running within the unit. But they would double the current seen by the CT since the supply conductors also carry the same current through the CT. It would make it easier to detect a low level fault with an increased amount of current flowing through the detection component.

I have only seen other conductors through the donut where a transformer was employed for the 120 volt loads, a GFCI before a transformer will not see a ground fault on it's secondary, as this fault, no matter how small will only be seen as a line to line current on the primary, so in these cases they will run the secondary of the transformer through the same donut coil to protect the 120 volt loads since it will drop out all voltage in the tub.
But these tubs were only 240 volt-3-wire H-H-G no supply neutral.
The GFCI on this tub as he described is a faceless levington with the coil that sticks out on the back as I described before. Maybe someone has an image of it, mines on another computer.