ECN Forum Forums General Topics of the Trade General Discussion Area Overwiring a house and other excesses

My problem with using the meter averages is it does not take into effect peak loads.
Things like spas may not be used very often but it is likely that when they do you might have a house full of kids, the oven may be going, you are using lots of hot water and there may be a load of towels in the dryer ... then someone gets cold and the wife turns on 15kw of toaster wire heat.

Of course every TV, computer and light in the house is on.

Greg...

The Poco -- for Service Drops -- figures on their experience -- and on the fact that such conductors are in Free Air.

3/0 XHHW-2 (90c) Aluminum is rated 275A in Free Air -- continuous duty. And that has to be a conservative rating, to boot.

The cyclic nature of hot tubs means that they don't run loaded up for 180 minutes of continuous draw. Further, the hotter the weather, the less they draw. Cold weather for the load also means more cooling for the Service Drop.

BTW, I never hear of any hot tub using heat pumps. For southern climates, such devices would do the trick for not a whole lot of cash.

For you never see patrons of the hot tub running out in the ice and snow to use them; and that's the only time they wouldn't pencil out.

The triplex drops here are #2 or maybe #1. They are nowhere close to 3/0

We only use the hot tub in the winter. I also don't pay to heat it until we use it so the heater can easily be called a continuous load. With a 11kw heater I still only get 10 degrees an hour. I could easily be starting with 65 degree water.
Since I plumbed the pool solars so I can switch them to the hot tub, that is less of a problem.

Victoria is an electric heat primary with some gas and oil too. 200 is pretty much the standard service size but few are over 60 amps of calculated load.
On the 75 KVA pole top transformer are 3 skinny houses, a duplex and a triplex. I think there is a 5 plex on it too but not certain the service to that building is from the back or the front. BC hydro sized resi services by the heat load and pretty much ignores the rest.
The 3 skinny houses are 100's the duplex and the triplex are 200. all Have electric heat and some split with gas. The utlity says the 75 KVA transformer can run %100 overload for 6 to 12 hours. I think they drop #1 or #2 aluminum for a 200 amp service and 266 for a 400 amp

Single family resi ranges from 200-400 amps (320/400). A few McMansions pushed the envelope for 'full 400', and at least 3 have 600 single phase.

The last townhouse subdivision was 150 amp each. The 22 unit condo bldgs have 800, 3 phase, with 100 to each condo.

The condos are off of either a 300 KVA pad, or two bldgs off of a 500KVA pad. Townhouses are BUD, 8 units to a BUD xfr.

As to the drops, '397' is common for 400-600 amp pole pigs.
Some old drops are 6 Al triplex!

The norm here for the pole pig is 25KVA for one house, 37KVA for 2 and 50KVA for 3.

These days we don't see 37KVA transformers much so if it blows you are probably getting a 50.

Greg:
If JCP&L did what your POCO does, all would be well. But then they would be crying for a rate increase.

My neighborhood had ten (10) houses on one really old 25KVA, which was 'good' when the houses were not all built, and some were only summer homes without AC.

Last year I did my most recent residence 2100 sq ft I roughed it in 2 days by myself. 4 bed two and half baths.

I feel like I'm overwiring a smaller place when I put in more than 2 or 3 230 V general purpose circuits (or maybe even 1 in a studio apartment) and 2 appliance circuits (dishwasher and washing machine)...
Recently I wired a large-ish condo (4 bed 1 bath) with 14 circuits... boy that felt like overkill! 7 in the kitchen alone, 150 m (almost 500') of flexible conduit for the kitchen renovation.

With 230/400 V you can get by with a rather small number of circuits in an average household.

Supplies aren't awfully large in Vienna either. Well into the 1970s 25 A 1ph was common (5.5 kVA max. load) and even today anything exceeding 35 A 3ph (roughly 24 kVA) is rare. On the other hand, the electric range is usually the largest load, followed by the dishwasher (those go up to 3.5 kW). AC is highly uncommon, except for the occasional portable, mini-split or window unit, all of which are content with a 16 A 1ph circuit (230 V 2w 1ph).

For feeder sizing, code requires 18 kVA per unit (electric cooking, gas or other hot water and heating) or 22 for a "fully electric household" (electric hot water). I think electric heating supplies have to be calculated according to the actual load.

If you cook with gas, you can even get by with 20 A 1ph in old places, although you'd better avoid running washing machine and dishwasher at the same time. Still more than the measly 15 A you get in Italy!

John,

I sent in pictures a long time ago about a house that was very over wired. In fact one of the pictures I sent in was given a caption of (Wires installed with an iron) or something like that. Each wire was run perfectly parallel with the next one. It was out here in cyberspace somewhere. Also each room had it's own video interface by the door. You can look outside through any of the numerous cameras, answer the phone, set t-stat temps,and even go out on the net. It took the EC about 1 year and a half to rough in.