I have a 220 volt 22 amp heater that I use for a greenhouse. It gets wet when I water and I want to protect it with a GFCI circuit breaker. My current panel is a subpanel on a detached garage. I have a GE Power mark subpanel box that fits plug in circuit breakers. My wire is 10 gauge copper and I currently have a 2 pole 30 amp circuit breaker. I have looked and looked but all I can find are a 20 amp and 50 amp circuit breaker. I can't use a 20 amp breaker because the heater is 22 amps. I can't use a 50 amp circuit breaker because my wire is too small. Therefore the only appropriate circuit breaker is a 30 amp breaker. Question #1: Is that statement above true? I assume it is so I will continue. I did buy a 30 amp GE GCFI circuit breaker but it is a screw in type. Question #2: Does a plug-in 30 amp GFCI circuit breaker exist that will fit a GE powermark plug-in style subpanel? If so, where can I get one? I assume that is does not because I cant find it anywhere on the internet. I could get the 50 amp breaker and run new thicker wire, but that is too much work. Therefore I have chosen to install a subpanel solely to house my 30 amp GCFI circuit breaker and as I read about this I had some questions. Question #3: Can I use the old 30 amp circuit breaker from the original subpanel to power the new subpanel and use 10 gauge wire to supply it if I only run the 22 amp heater off of it? Or do I need a higher amp circuit breaker and wire connecting the two subpanels? Question #4: Do I bond the new subpanel with a green screw or not? The original subpanel in the detached garage does not have a green bonding screw nor a grounding rod. Question #5: Should I bond the original subpanel with a green screw and run a grounding rod or just leave it as it is.

I realize 3P motors are more efficient and can result in lower electrical bills, but do 3 phase efficiencies apply to any other loads? More specifically if I have three single phase resistance heaters that are connected to a 3p service using two each of the 3 phases(A & B to one heater and B & C to another and A & C to the third) is there any energy savings or is it simply the combined wattage's of each heater that goes into the billing? Or another way of asking the question is how important is it to keep loads balanced on a 3 phase service as it relates to cost. Thanks