AdrianWint
Senior Member
- Location
- Midlands, UK
Do you remember when you where at school/college and the physics teacher produced some kind of apparatus that demonstrated some law or effect - thats the kind of thing we make. They range from simple stuff like structures to a complicated power system simulator which teaches generation (inc generator characteristic), transformation, transmission, distribution & protection (using real digital protection relays). One of the process control rigs teaches control techniques using hot & cold water, the mixing of which is overseen by PID controller which the student programs. For those interested, I could provide a link to our wedsite......would that count as selling & thus break the rules of the forum?
augie47 - Thanks for the pointers about listing. My brief is to understand the power supply issues. Another team of guys is looking at legal & listing etc issues. I've passed your comments onto them.
Mpoulton & all - thanks for the comments about the colour codes. Pretty much along the lines I was thinking - our Brown, Blue & green/Yellow is OK for the simple 120V supplies but for 240V supplies, particually if a neutral is required, we need to obtain & fit a cord with US colors since our European color code is at odds with the NEC code.
Points about the 240V IEC C15 also noted. The IEC C15 has a big brother, the IEC C19, rated at 20A. This is starting to be used in the UK for higher power items. Is this connector appearing in the US? Would you expect this to be a 120V connector or a 240V one?
Time to feed back some information......
In the UK we only really have one power service. This is distrbuted as 400/230V WYE. In the home we only have 230V single phase available - supplied as one phase of the street distributor & neutral. The neutral will be soldily grounded at the substation by the utility company (known here as a DNO - Distribution Network Operator). The capacity of the supply will be 80 to 100A ie around 20kW. Earthing may be TT (local earth rod, no connection between N & E at the customer site, RCD (= your GFCI) complusory) or PME (local earth rod, N & E joined by the DNO before the meter, no requirement for RCD since earth loop impednace will be small (less than 0.35 Ohms). Anything other than a very small business will have a 400V service consisting of the three phases & neutral. Capacity will be 100 to 400A per phase. This will come from the same transformer as supplies local homes (indeed it may even be off the same cable). Within the business, lighting & socket outlets will be fed from 1 phase & neutral. Motor loads & A/C will be fed with all three phases.
dbuckley - I concur. I'm still very much learning about the systems employed in other countries and find the differences fasinating. Your point about the neutral conductor is very true, we have to treat all current carrying conductors as live conductors, providing insulation & isolation as though it where a phase. Are you the same dbuckey whom is a fellow contributor to The Blueroom forum?
Adrian