70 amp service

Boondox · Jun 18, 2003

Our 165 year old home was wired in the 1950s with 70 amp service. After a fire we replaced the old coke bottle fuses with a modern circuit breaker box, but still have some concerns about the anemic power. My wife complains that the air cleaner and reading lights in the house vary in speed/intensity whenever I'm using my MIG welder or woodworking tools.

70 amps is low, but how much is enough? I know we're responsible for the connection from the pole to the house, but how can I tell if there's enough juice on the town's end to give me more? We're the last house on a long dirt road, and while the rich woman in the mansion 1/4 mile down the road has 400 amp service , the town did no improvements on our end.

Pete

MarkV · Jun 18, 2003

Pete, it would be unusual for the power company side of things not to have enough power. 70 amps is a pretty small service by today's standards. Welders, microwaves, any electric motors in the shop all draw pretty heavy loads and particularly at start up. If you upgrade your service I would go 200 amps and be done with it.

I love those old houses and have enjoyed the photo's of yours. One of these days I'd like see your place.

MarkV

tc35dforme · Jun 18, 2003

Like Mark said, 200 amp is the norm for houses these days. There are however, plenty running 100 amp services without much trouble. The key is the number of high amperage loads and their likely concurrent use. ( good pun huh ?? /forums/images/graemlins/grin.gif )

For example...well pump ( 30 amps )..stove ( 50 amps ) ...dryer ( 30 amps )...air conditioner ( 30 amps )...now add in lights and television, that hair dryer... etc.

It isn't likely that you will need to run everything at once, but you need to cover your maximum anticipated demand.

From a practical standpoint, the cost for you to buy a 200 amp panel as opposed to a 100 amp is minimal. The labor cost is the greater percentage of the job, and the labor is about equal for both installations. You may be looking at only $ 100 more to get the bigger panel. The number of circuits will be the same, you'll just have more future capacity with the 200 or the opportunity to split loads ( welder ).

Call the power company...most are required to provide you the power you require ( to a point ) by law. Getting a few hundred amps on a primary feed is easy for them.

RobS · Jun 18, 2003

Pete, I'd agree with MarkV; the town power to your location should be adequate. Two things to consider are your incoming service (yes 70 is pretty short these days) and the distance from the transformer to your house.

Call your local utility and ask for technical person to come out and evaluate your situation. They should be considering a larger transformer and perhaps closer to your meter/panel. From there you can put in a larger panel and tie all of your existing circuits into it as well as a dedicated line for that welder of yours /forums/images/graemlins/smile.gif

Anonymous Poster · Jun 18, 2003

You may find that upgrading will require you to comply with current codes. Ask your building department for their take on your situation.

Like the others, I vote for 200 amp service, everything else being equal.

BTW, we have 400 amps here (individual 200 amp services for house and shop). There is nothing special about the power feed. Just the usual transformers tapped into the power company's line down the valley.

SnowRidge

MossRoad · Jun 18, 2003

We have 100 AMP service. It is adequate, but that's all. I have a 220 well and air conditioner in the house, a breaker for each rooms' outlets and every two rooms share a lighting circuit. The bathroom has its own circuit. There are 3 circuits in the kitchen. The major appliances are all gas. There is no room for expansion. I do have a 50AMP 220 to a sub panel in the garage, where I run a welder. But if the pool pump is on, I am running the welder and the air compressor kicks on, I might pop the breaker. I have to do manual power management(turn off breakers selectively /forums/images/graemlins/wink.gif).

If you're going to spend the money to upgrade from 70, go with 200. You will be much happier and have plenty of room for expansion.

cisco · Jun 18, 2003

I currently have 60 amp service on my country property, cause that's all the county would allow if there are no dwellings (just have a well, and power/water outlets scattered around), and even then one has to justify the amps requested. The county apparantly leery of one setting up a cheapo trailer park or similar sans permission. I'm now taking bids for a tractor/boat garage with an efficiency apartment on the second floor (to be a future guest house). The county will only allot 120 amps for such, UNLESS one uses "key" terms on the permit form - like "welding unit" or "central air conditioning" (unusual for a garage). Your licensing authority may have similar restrictions, and it may pay to find out what they are before filling out the permit form.
So, I'm putting in a "welding unit", and will be alloted 200 amp service (when I eventually put in the main house, I'll get up to 100 amps more)

rancar · Jun 18, 2003

200 amp service should be more than adequate for the needs as you've described it. 400 amps is overkill.

...Bob

Anonymous Poster · Jun 18, 2003

I agree with the other posts. You should go with a 200 amp service. I'm not familiar with your state/county/local coding but you should at least follow the latest NEC (National Electric Code) when upgrading.

You can check with your electric utility and they can tell you how much power they can supply without an upgrade. As 1 poster said they have the burden to supply you with reasonable power but most have already upgraded over the years to keep ahead of demand.

As for your flickering, I suspect it's either your feeder or the power company's feeder size that's the culprit. You said that you changed the fuses to breakers but you didn't say if you replaced the feeder. It could also be you pole transformer size.

I would also consider dual distributions unless your situation prevents it.

dummy · Jun 18, 2003

This is an FYI message. On our last house, after doing some remodeling/rewiring the wife complained of the same type of things. Yes, she was right. After triple checking my work I called the power company. Seems that the wiring on the transformer was loose enough that a slight breeze would allow it to intermittently connect flickering lights, etc. inside.
I would also vote for a 200 amp upgrade.

bgott · Jun 18, 2003

I had heavy duty flickering and light bulbs blowing for years. It turned out to be the neutral in the power company drop that had the insulation blown off every foot of the entire length.

dummy · Jun 18, 2003

Guess as long as no one complains everything is AOK. Appears that there isn't a standard interval for wiring checks/ replacement.

Gary_in_Indiana · Jun 18, 2003

Snowridge,

I have a question on your 400 amp setup. You said you have 200 for the house and 200 for the shop and I'm curious as to what method you used to do that. Do you get two electric bills every month for two separate meters or is everything run from the pole to the house then house to shop (or pole to shop to house)? If that's the case, don't you need 400 amp service at the first box off the pole (be that house or shop) and then run 200 amps off of it to the second box for the 200 amp service there?

grainger12002 · Jun 18, 2003

My vote is also for the 200 amp upgrade, the cost is very minimal as compared to the 100 amp,do it once and be done with it,maybe even leave some room for future expansion-good luck. 70 amps is too small.

Boondox · Jun 18, 2003

I've noticed more fluctuation in storms as well, and in a breezy rain I get knocked offline every 4-5 minutes. Might be something else to look into...

Boondox · Jun 18, 2003

( I would also consider dual distributions unless your situation prevents it )

Ummm, freely professing my ignorance here...what is a dual distribution? /forums/images/graemlins/crazy.gif Pete

Anonymous Poster · Jun 18, 2003

( I have a question on your 400 amp setup. You said you have 200 for the house and 200 for the shop and I'm curious as to what method you used to do that. )

The shop and house are completely independent and have separate transformers and meters. Yes, we get two bills and pay twice the monthly meter charge because of it.

The utility's overhead power line crosses the front of our property. In the case of the house, the transformer is located on the closest pole. The feed then goes underground to the house.

The shop is different. High voltage is taken directly from that same pole, runs under ground to a dedicated pole near to the shop. It goes to a transformer at the top of the pole. From there it runs back down under ground, crosses under the pasture road, and goes to the panel on the side of the shop. There is a power company owned security light on top of the pole. That particular pole serves no other purpose, and looks really strange sittling out there all by itself with no overhead wires connected to it.

Power from a breaker in the shop's 200 amp panel then runs underground to the garage (which is next to the house) and feeds a 60 amp sub-panel.

This setup was here when we bought the place. We have no idea why it was done this way, and frankly it doesn't make a lot of sense, other than the building sequence was house, shop, garage.

Having separate services on separate transformers has two distinct drawbacks.

1. We pay the base meter charge twice, which is an extra $10 a month, thereabouts.

2. We can't use a wireless intercom between the house and the shop because the signal that they superimpose on the AC won't pass through a power transformer.

If both buildings had their 200 amp services supplied from the same transformer, then we could have used a wireless intercom.

Why the previous owner chose to run power to the garage from the shop is beyond me. The shop is about a 200 foot run. The house would have been around 50.

Of course having separate services means my shop acitivities don't impact the house, but I don't know that they would have anyway.

SnowRidge

Gary_in_Indiana · Jun 18, 2003

I'd go with 200 amp service, too. I ran new service to a freestanding barn recently and went that way. I don't remember the exact cost difference but I'm sure it was under $100 and may well have even been closer to $50. I can't imagine ever needing the 200 amp service in the barn, but for the few dollars difference I liked the idea of never having to wish I'd done it when I had the chance.

The cost of upgrading from 100 to 200 amp service at the time I did this was $600 to $1,200. I figured that was only going to go up so I invested the small money now to ensure I wouldn't have to spend the big money later if I ever did need 200 amps there.

Good luck with whatever you decide. I hope this helps. /forums/images/graemlins/smile.gif

uhmgawa · Jun 18, 2003

( Our 165 year old home was wired in the 1950s with 70 amp service. After a fire we replaced the old coke bottle fuses with a modern circuit breaker box, but still have some concerns about the anemic power. My wife complains that the air cleaner and reading lights in the house vary in speed/intensity whenever I'm using my MIG welder or woodworking tools.

70 amps is low, but how much is enough? I know we're responsible for the connection from the pole to the house, but how can I tell if there's enough juice on the town's end to give me more? We're the last house on a long dirt road, and while the rich woman in the mansion 1/4 mile down the road has 400 amp service , the town did no improvements on our end.

Pete )

You may want to talk to your utility company and explain
the situation. Your transformer/lateral may be undersized
or shared with another service.

Utility companies seem not to be bound by NEC. Such that
they can run lighter gauge service laterals from the
transformer to your meter than you are allowed to run from
the meter into the service entrance.

Anonymous Poster · Jun 18, 2003

Most electrical contractors do "heavy ups" to 200 amp services regularly. I agree, go with the 200 amp service. The power company will have to be involved anyway, as they will have to cut power for the change over (unless its done hot), and they will have to put a new lock on the new meter.
Good luck,
DaveL