I remeber an article some years ago about proper locations for telephone poles with transformers attached. I can't seem to find it however. Were they mainly step-down transformers leading to individual customers or were there such transformers that were along the line that did not have drops to customers?
I found the Walthers Utility Pole set to be a good starting point for power lines on a layout. I've only placed pole-mounted transformers where a customer would have needed service.
Utility Pole by Edmund, on Flickr
That's not to say there weren't transformers placed elsewhere, maybe in anticipation of future tie-ins? Sometimes intermediate transformers are placed for use in street lighting.
Utility Pole_0001 by Edmund, on Flickr
Utility Pole_0002 by Edmund, on Flickr
I sometimes place transformer pads close to some of my industrial buildings which make interesting details.
Under-Bridge-xfmr by Edmund, on Flickr
This one will be fenced in eventually:
Under-Bridge-cars by Edmund, on Flickr
This unit is mounted on the roof of a mill building:
Mill_power by Edmund, on Flickr
Utility Pole_0004 by Edmund, on Flickr
I think industrial scenes benefit from having small sub-stations and transformer pads represented. This is an actual scene I'd like to model:
Night Scene by Jerry Jordak, on Flickr
Good Luck, Ed
It seems to change by region.
Down here in Florida, it seems like every pole that drops to a customer has a transformer on it.
In Indiana, very few poles feeding residences have a transformer on the pole.
-Kevin
Living the dream.
I think dick ellwell was a line man and wrote articles. I remember one of Alan kellers videos had a how to on doing that. There is a guy on eBay selling premade poles already configured. They are nice looking too. Seams to be one step down feeds a certain number of homes. Same with business of course the more draw the more likely they have thier own step down I am currently on a street where every business has a transformer but the houses at the end don't
shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
Thanks to all for the help. Much appreciated.
I'm about to embark on correctly wiring poles myself. Upon observation while out driving, I took not that where ever a drop from the main is required, a transformer exists. In rural areas where houses are further apart, every house had a transformer on the pole out front. Where houses are more closely grouped, one transformer would feed all the homes that a lead could be strung to.
I'm sure things may be different in more congested areas where lines are also run under ground.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
OK,
Distribution - highest wires on the pole - distribution voltage - 4,160 volts/3 phase in the old days, now 13,200 volts/3 phase in most places.
Residential - Typical single phase transformer tap - one transformer can - lowers voltage to 120/240 - single phase. Typically serves 4-8 single family homes with 100 to 200 amp services. Wiring from transformer to homes lower or pole, may be individual conductors or spiral cable assembly - two hot wires and a neutral.
Commerical - Three phase tap - three transformer cans - lowers voltage to 480/277 - 3 phase, or 120/208 - 3 phase, for small or medium sized commercial buildings - secondary wiring similar to residential but will be larger/heavier looking - three hot wires and a neutral.
Large industrial/commerical customers will get high voltage and have their own on-site transformers. They may be groups of three or one large "box" 3 phase transformer.
Other details, transformer poles will have ground rods, seemingly radom, so will some intermediate poles.
Extremely rural dead end pole lines may only have one high voltage wire, a neutral cable, no cross arms, and feed as many as a dozen single phase transformers before just dead ending at the last transformer pole.
Last 25-35 years, many transformers are pad mounted on the ground and drops to homes are underground even if the high voltage is still on poles. High voltage runs down nearest pole, to the transformer, low voltage underground to meter box on building.
Typical residential pad mount serves 4 homes.
Some large homes or medium businesses will have two separate drops (200 to 400 amps each) rather than a larger single feeder. This installation is less expnsive for both the power company and the customer at the time of construction.
Many power company poles are shared with phone and cable providers, but many poles with large diameter cables are just phone wires - even today.
More specific questions welcomed.
Sheldon
I used to work for a small telephone company in central Florida. One of the tasks every five years was a "Pole Count". There is a fee for other services to attach to utility poles owned by the power company. So for a few months a crew had the very exciting job of inventorying every TELCO attachment to every utility pole in our service area. The variety of what was seen attached to those poles is something else. Of coure in some cases the telephone company also had their own poles but the power company never attached to them. Then along came the cable TV companies and they made a real mess of things.
Mike in NC,
Telephone transformers seem to vary in distance and type. It seems the circular (can) type is common. I am not sure how often they are spaced apart on the rails compared to rural or industrial areas.
Wouldn't it make sense to wire a transformer to a substation or something similar? I've read some don't even bother putting up telephone lines to avoid knocking into them when doing work. With my luck, I'd get my arms dangled up in the wires often.
kasskaboose Telephone transformers seem to vary in distance and type. It seems the circular (can) type is common. I am not sure how often they are spaced apart on the rails compared to rural or industrial areas. Wouldn't it make sense to wire a transformer to a substation or something similar? I've read some don't even bother putting up telephone lines to avoid knocking into them when doing work. With my luck, I'd get my arms dangled up in the wires often.
There is a limit to how far lower voltages will travel without noticable voltage drop, so the transformer that lowers the voltage from 13,200 down to 120/240 for your house needs to be near your house, 500', more or less.
Even the 13,200 volt lines have voltage drop and are "boosted" in places along the way.
People think electricity is magic, and in a way it is. You have never seen it, only what it can do.
But it does actually take energy to get it from the power plant to you, and if there is no use for it in a second or two after it is generated - it is lost and the energy used to generate it is wasted.
Contrary to current popular opinion, electricity is not the answer to all our energy needs - and that opinion is coming from an electrician and electrical designer.
A few "correct" terms:
If it has power lines and phone/cable lines, it is a "utility pole".
If it is owned by the phone company and only has telephone wires, it is a "telephone" pole.
If it only has electrical power lines, it is a "power pole", but is often still called a "utility pole" by the power company.
Why do we still use overhead wiring rather than put it all undrground? Cost. Underground wiring cost more by a factor of 5 to 10 times, sometimes more. And repair costs are dramaticly more. Would you like your electric bill to be 5 times higher?
Outstandng when someone really knows their stuff and provide more clarification. Super helpful having such folks here able to impart knowledge.
Far more magical than electricity itself is when people can make complex subjects even remotely understandable. Quite shocking (pun DEF intended; #dadjokes).
Why would you mount your transformer on a telephone pole? Must be a cog incline model railway.