- Jul 23, 2014
- Reaction score
Terry, I know how they work. I have been advocating their use on forums for years. Have you read this thread? I have illustrated my setup in this thread with a link to my automatic transfer switch battery backup system that highlights two twenty Amp circuits, each with GFCI breakers not outlets, life support equipment split and an automatic battery backup on deep cycle marine batteries. I know all about it.I understand it is hard to visualize. Let me try. There are two sockets in the wall. Each one I have pluged a gfi extension cord in each socket. The socket itself is not gfi. Then on the protected side I have my equipment pluged in. Any trouble on either gfi circuit due to leaking voltage will shut power off effectively isolating the failed item. And yes all equipment pluged into that gfi will have zero power applied.
The way gfi circuits work is they monitor current on one line Hot usually black wire and compare to the current on the other line, white wire. Any current diference trips the gfi. Like a pump voltage leaking into the tank due to let's say a leaking seal. The current on the hot wire conected to the gfi will be higher than current on the return wire. This is because the pump continues to draw current, let's say 1 amp. So 1 amp is detected by hot wire and return. That is ok but there is now an additional current draw through the tank because the seal failed allowing saltwater to enter the pump's electrical copper winding. The leaking voltage will draw current through my ground probe or other source. Let's say that extra draw is .25 Amps. Now the gfi detects 1.25 on the hot wire and 1 amp on return and the gfi trips. The 2nd gfi will typically not trigger as the current required to operate the equipment on the 2nd gfi is completely seperate from the equipment on the 1st gfi with a failed pump.
Willieboy said he has two circuits, but only one is protected. The other unprotected circuit has just his return pump. My argument is if he has split his life support over two circuits then it doesn't make any sense to have an unprotected circuit. I further added if anyone is arguing against GFCI outlets because they may defectively trip killing life support it really shouldn't matter because they should have a battery back up. If they don't then where's the logic behind not using GFCI because it could trip, yet a more common scenario is utility power was cut off killing life support.
I will link to my post again in this thread illustrating my setup.
On a different forum I shared my battery backup system and figured I would add it here to help anyone looking for a solid setup. Yes, there are many ways to do it, but from my research UPSs are unreliable and only last a few hours depending on the model. Some aquarium product manufacturers...