What is the defferent between 3phase 3 wire and 3 phase 4 wire energy meter?

I have a single phase 238-240v air handler with 15 kw(3 - 5kw strips) of heat strips. I want to wire this with 3 ph 208 wye. Can I change the wiring to this: L1 ~~~H1~~~L2 / L3 ~~~H2~~~L1 / L2~~~H3~~~L3. Then send L1 & L2 to the 240 system fan for a single phase fan motor. This Should give me a...

I have a old 60 AMP feeder line from the top of my house to the meter. From the meter is 200 AMP new wire. I was wondering if this is even safe and what would the cost be of updating the feeder line?

I hope the energy meter will consider only the amount of current flow in case if I improve p.f. And reduce the current flow in mains circuit,is it will help to reduce my eletricity bill, and reducing produce heat, loss of electricity. Kindly pardon my english.thanks

Have heard this can be done but wanted to get some help. Have a three phase welder and wondered if I can directly wire a single phase line to it? I realize I would loose 66% of the out put which is fine but just wanted to know if it can be done. If so were do I put the single phase lines to? ...