Ross Herbert said:
Perhaps I am missing something here. If the OP has "his own
transformer" which I assume is single phase (MEN ?), then where does
the "both sides ending up in series" come from?
Ross think of it this way.
A typical North American service is 'three wire' from the transformer
outside, often pole mounted.
Our service which is typical has a three wire triplex from the service pole
to the metal service mast/conduit on its way to the meter mounted on the
outside of the house.
Consider the middle or centre wire is zero or neutral. Typically white. Note
1.
One outer wire is (sort of) plus 115 volts, this is say red. Leg A.
The other outer wire is (sort of) minus 115 volts, it is say black. Leg B.
I say 'sort of' because this is of course AC at 60 Hz; but use plus/minus to
illustrate; OK?
Leg A and Leg B are the two 'ends' of a single phase 230 volt winding of the
electric company step down 'distribution' transformer. Although they are
sometimes mistakenly called 'phases'! The 230 volt winding is centre tapped
and this is the zero reference point or neutral.
So between Leg A an Leg B there is 230 volts; (with neither wire at zero or
neutral), we use this for heavy appliances such as water heaters, cooking
stoves etc. maybe a welder in a home workshop, my bench saw has a 230 volt
motor for example etc. These 230 volt circuits are connected through two
pole breakers. I also have a 230 volt outlet above the work bench for the
occasional use of anything 230 volt!
There is 115 between the red and neutral and 115 between black and neutral.
Typically the other house circuits, 115 volt lighting, convenience outlets
etc. are evenly distributed between and served through single pole breakers.
We do not seem to use 'Ring Mains' as they do in the UK! Appliance plugs do
not contain fuses.
Individual (radial) lighting circuits typically #14 AWG at 15 amps, outlet
radial circuits either #AWG at 20 amps or #14 AWG at 15 amps.
Ground wires within the residence are either bare wire within the cable
sheath or green.
Note 1. The neutral is grounded 'once' at the main panel where it enters the
house and depending on the jurisdiction there are various bonding
requirements to other utilities such as water pipes etc.
Personally I think it's good system and while 115 volt does result in higher
amperages for some plug in devices those that do use any large amount of
wattage, such as an electric kettle, toaster or a fridge are used
intermittently.
Any help?