What Scotty says. Sounds like you have a common ground mesh, or linked meshes (electrodes) across the site. In this respect you're describing a TN system, so no problem so long as the ground mesh is adequately sized to carry fault current. If your electrodes are independent you've got a TT...
Hi Sparky,
Principles are the same, just watch the values may be slightly different between type 2 and type B for instance.
Also don't forget that the maximum ambient test figures should be 0.8x these figures to take into account the increase of resistance of the conductors with the increase...
Yup. 25kA/1sec should be OK with normal motor loads, etc. Agree with Scotty re volt drop. Wiring Regs (see Appx12) now much more relaxed for private supplies, unless you have a specific voltage drop problem?
Sparky,
Short answer is - Yes you do.
Assuming you're UK based, the relevant section in the Wiring Regulations (17th Edition) is 411.8 and table 41.6. It's basically the same calc as for a 230V system, thus Max Zs for:
type B breaker at 55V = 11/In Ohm
type C breaker at 55V = 5.5/In Ohm
type D...
G'day Sunnyoz,
Not sure if your transfer switch gives isolated changeover or a degree of parallel running. If there is a chance of parallel running, I'd advise making your Neutral-Earth connection in the switchboard with restricted-earth fault protection on each of the generator feeders.
If it...
Centaur-
Try this link for a download of "Lumdat":
http://light.peters-research.com/lumdat.htm
You'll soon find out how much fundamental data you need from the manufacturer and probably give up like me!!
