Neutral for GFCI breaker

[Part 77]

I need to move a 50 amp single phase 208 volt Seimans GFCI breaker (which is installed in a lighting panel) feeding a transfer switch. The transfer switch feeds a portable steam cleaner and a "bearing heater" because it was determined that the mechanics would rarely, if ever, need to use both at once in this shop. The "bearing heater" is an old 3 wire GE kitchen range. The range will trip the GFCI breaker intermittently. I have been through it and the main oven element meggers 50k to ground. There are other low readings on the broil and cleaning elements, but this is the lowest and the only one used for heating bearings.The breaker doesn't seem to like this. The guick fix would be to put the required (at least for the steam cleaner) GFCI breaker down stream of the transfer switch. I would like to tap a short run of neutral from nearby to save running a "dedicated" neut. for the breaker some 200 ' back to the panel. Knowing GFCI outlets don't work on shared neutrals, I'm wondering if the breaker will be the same. I never understood why sharing a neut on GFCIs was a problem as they are all "common" back to the neutral bar anyway. Any ideas?
Thanks.

 

[iwire]

Number one

I would like to tap a short run of neutral from nearby to save running a "dedicated" neut.

Put that thought completely out of your mind, you can not just 'grab' any neutral.

Number two

The "bearing heater" is an old 3 wire GE kitchen range. The range will trip the GFCI breaker intermittently.

Being three wire the range should have a bonding strap from neutral to the frame, if the frame hits other grounded objects that would trip your GFCI.

The range will need to be converted to a 4 wire range and outlet and the bonding strap removed.

 

[Part 77]

More info. The neutral in the range had been isolated from the ground conductor when the transfer switch was installed which was tripping the GFCI right off the bat. It was determined the clock was not needed or any other loads with a neutral. i.e. indicating lamps, burners. So, is a dedicated neutral needed for the GFCI due to design or code?

 

[brantmacga]

Knowing GFCI outlets don't work on shared neutrals, I'm wondering if the breaker will be the same. I never understood why sharing a neut on GFCIs was a problem as they are all "common" back to the neutral bar anyway. Any ideas?

they work the same. both measure current difference between the grounded and ungrounded conductors.

I would like to tap a short run of neutral from nearby to save running a "dedicated" neut. for the breaker some 200

this will not work because of what i just stated above. plus all that bob said.