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| Thread ID: 113033 | 2010-10-02 05:02:00 | # of circuit breakers an Point-of-entry telephone cable | CCF (6760) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1141136 | 2010-10-04 18:50:00 | That's a rather old document now. There have been a lot of changes, so many that I can't get straight answers from my neighbour who's an electrician. In many aspects the new Regs seem so confusing that the words should be replaced with pictures :D | PaulD (232) | ||
| 1141137 | 2010-10-04 22:41:00 | That's a rather old document now. There have been a lot of changes, so many that I can't get straight answers from my neighbour who's an electrician. In many aspects the new Regs seem so confusing that the words should be replaced with pictures :D Well could you point us in the direction of the new one, as the one I posted was the newest one on the MED website. This 2004 document was updated in 2007 to cover RCD circuits. Anyway it has a lot of info for CCF. |
wmoore (6009) | ||
| 1141138 | 2010-10-05 02:52:00 | If Billy's patience hasn't run out he may comment further My patience rarely runs out, but I usually try to stop before I bore everybody to tears. However, "roping" is not a term recognised in this country and would show up a rank amateur inside of 2 minutes. You can 'run' cables, or you can 'pull' cables and from time to time you may 'feed' cables or even curse cables, but the only time you would rope them is when you are about to hang yourself. If not careful you will end up with a house that cannot be connected to the supply system, will be uninsurable and unsaleable. Running or pulling cables is not as simple as it may look, and there are many many fish-hooks for the unwary. Further, the US environment is so different to ours that they might as well be on another planet, so as keen as SJ may be, his advice is of very little relevance at all. If they require significant current, such as for cooking appliances, water heating or any other heavy drain they need a three wire supply. In very simple terms, they use 1&2 or 2&3 for 115 volts, and 1&3 for 230 volts. It is interesting to see that the US system for performing unqualified electrical work is based on no care and all responsibility, while the formal certification is based on visible inspection only and no responsibility. Figures...... Cheers Billy 8-{) |
Billy T (70) | ||
| 1141139 | 2010-10-05 04:28:00 | Further, the US environment is so different to ours that they might as well be on another planet, so as keen as SJ may be, his advice is of very little relevance at all . If they require significant current, such as for cooking appliances, water heating or any other heavy drain they need a three wire supply . In very simple terms, they use 1&2 or 2&3 for 115 volts, and 1&3 for 230 volts . It is interesting to see that the US system for performing unqualified electrical work is based on no care and all responsibility, while the formal certification is based on visible inspection only and no responsibility . Figures . . . . . . Cheers Billy 8-{) I understand your chagrin over the reluctance of a certified electrician to actually take any responsibility for previous owner/contractor work - but mostly the US it's the consumer who sets the limits on his own property and this never happens in a commercial building or one that might have the general public inside of it . An electrician will always meg-out and ring every circuit to insure it's continuity - but the actual wire gauge and whatever and integrity of the connections in a wall boxes or whatever, are not part of the electrician's responsibility if the owner doesn't want to pay him for the work . It is so noted on the inspection forms and the owner assumes full responsibility for anything he has done that is not up to code if the electrician cannot see or test it reliably . When Edison powers the job up - if the pole fuses have been removed or a construction meter has been installed and then it needs to go back to the consumer's meter, if the house doesn't smoke much and glow too brightly in full daylight, then Edison's job is over and their responsibility ends at the main breakers on the pole . After the breakers are reset one at a time and they actually hold - then the electrician's job on an owner/contractor's job is complete and he too, can leave . A man's home is his castle, even if he later burns it to the basement sill plates and that's just the way it is . That law is considered sacred . There are times when a licensed electrician can work and not be working on his license too . He is considered 'moonlighting' and he isn't called to any liability if a problem appears and he's not working on his license . This happens with friends who do work for each other and sometimes an electrician can be licensed ONLY when he's on a job of his employer's and any other time he's on his own . The is called an "RME" (Responsible Managing Employee) and he's only licensed on the job site as a sub contractor . Confusing, huh? It just keeps the courts from a lot of overload . The following diatribe is just for Billy, as I know he knows the lingo and can understand this - but anyone can ask a question if they like . :waughh: ~~~~~~~~~~~~~~~~ Most of the Olde U . S . system was the way you cited - but the current standard is 117/208-1φ and commercial/light-industrial systems are 277/3φ . The pole drops are usually 200 Amps for a residence with no electric water heater or over 2 1/2 HP A/C - and if they need electric heat and/or A/C, add another 60 to 100 Amps . In modern homes it's not uncommon to see 300 Amp service especially if they have a Hybrid or electric car . Yeah - we run three legs, 2 of them together are 208 and the central leg is Common/Neutral . Leg A & B are 117/122 return to Common/Neutral - and tied together they are A + B = 208, with no ground needed to get current, but the Common leg is always attached for system grounds and run back to the Neutral buss in the D-Box . The math may confuse people, but it's the transformer design on the pole that creates all the new-odd voltages . Because of eddy currents, the older system was found to be rife with hysteresis losses and the oil in the transformers was all PCBs anyway - so they had to go . It was a very major undertaking! The whole country is still not completely changed-out and it still goes on . IN the house I am in right now - without any ballasting transformers to boost the voltage, I'd be at about 88-90 VAC right now . This is a very old system here, and quite frankly if I had to pay for the Amps that they need to boost me to normal household voltages, I'd be broke in a few months . The onus is on the electrical co-op here and they are losing a lot of money . That's the good ol' American way . By Federal Law, they cannot provide me with less that 105/210 and if they do, I get it for free until they get it fixed . Big whoopie! Commercial buildings are now being converted over to 277/3φ, as most were just 120/120 or 240/1φ . Heavier industries are 480/3φ and the next step up is 25 KVA/3φ, which I have worked on LIVE at a major LA hospital . I hate 480/3φ absolutley and with utter respect . Anyway ::: The older Delta Residential System was 230-240/1φ and the new Triad Residential System is 208-217/1φ . C-leg is always NEUTRAL and the biggest difference is that the old Delta also had another GROUND that ran from the pole drop and went to a separate bus for case grounding . This makes it really tricky to add a slave or piggy-back d-box in a new addition or whatever, since you have to float the ground and rely on a EUFER for GFCI integrity . This was done away with and both the GROUND and the NEUTRAL are now tied together: there is no Ground bus in the distribution panel any more . The Neutral goes all the way back to the generating station for the final loop of the supply . The US uses closed loop, full return systems, not 220 single-leg-to-ground . Done right, there's no problems, but this really confuses the old guys who haven't stayed up with the new voltages and Common-Tied-Neutral and when they look for the old Ground/Green buss, it ain't there any more! The new Electrical Codes (US Codes) require GFCI on any new or remodels done after Jan 01/2001 and they are 100% tested! ENTHUSIASTICALLY TESTED! No matter what system I get to work on, I always install an 18-foot long Ground Anode driven into the ground and also tie into the EUFER, which is a 12 foot piece of rebar cast into the foundation of the building and sky'd out for attaching the Ground in the local d-box or a nearby Hi-Amp circuit like a clothes drier or an AC/Heater unit . It's just extra insurance . ALL electrical motors require dedicated home runs and Neutrals back to the box, and all legs are d-box-GFCI'd . Motors include any garbage disposals, HVAC motors, Microwave ovens (even portable), trash compactors, ceiling vents that are motorized and of course, each bathroom must have a dedicated and separate receptacles and the lights may NOT be on the same circuit - but MUST be on the same leg . Any ballasted lights must be on a dedicated circuit per room, but must be on the same leg as the rest of the room . Hard-wired (installed) lights may NOT be mixed with wall receptacles or vice versa but must be on the same leg as the rest of the room . All exterior lighting and circuits and garage circuits must stand alone in a dedicated d-box, with it's own breakers and GFCI circuits . So - as you can see, the Rules Of '01 in the US are very strict . Next is the Rules Of 2011, and they are even stricter . They will from that point on - not allow any owner/contractor to do any work that is behind walls or overhead without a licensed specialist (plumbing/steamfitter - electrician - HVAC specialist) on the job at the same time any work is being done by the owner . |
SurferJoe46 (51) | ||
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