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fifty nine

join:2002-09-25
Sussex, NJ
kudos:2
reply to pandora

Re: The renovation continues ... today new 400 amp service!

said by pandora:

said by ncbill:

So why didn't you pick a ground source heat pump?

IIRC, those are more efficient for heating than air-source, plus can be configured to provide hot water.

It saves me $60,000 for the time being, later a ground heat pump solution can be installed. I tried, but the price difference was too great.

You get back 30% of that on your taxes, which is about 18 grand. I would have done geothermal if I had the opportunity.

kherr
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Collinsville, IL
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reply to DKS

Back when I lived at Lake of the Ozarks we set a bunch of 600A services at houses. They were all electric homes. One house figured to need an 800A, but when the customer found out the cost between us and the utility he went back to the HVAC people to have them to take off some of the elements from the furnaces. It ended up with 4 fiull 40 panels with each 2/3 full.

We worked on some monster homes, but I never really asked anyone about the sq.ft.age. These were all "vacation" homes that some years nobody would even come down to ... must be nice.



cdru
Go Colts
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Fort Wayne, IN
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reply to pandora

said by pandora:

Two 200 amp transfer switches for 1 Generac 20 KW.

<scratches head>That's a little over 80 amps. Wouldn't one ATS have been enough?

It's your money I guess...


nunya
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It's because of the split service. Have you seen the price of the $400A transfer switch?

It probably would have been better to have two panels: essential circuits and non-essential circuits. Especially since they are right next to each other. Then he would have only needed one ATS.
--
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pandora
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reply to fifty nine

said by fifty nine:

You get back 30% of that on your taxes, which is about 18 grand. I would have done geothermal if I had the opportunity.

When I ran the numbers, my total cost would be $60,000.

Each family has it's own unique situation.
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"

pandora
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reply to nunya

said by nunya:

It's because of the split service. Have you seen the price of the $400A transfer switch?

It probably would have been better to have two panels: essential circuits and non-essential circuits. Especially since they are right next to each other. Then he would have only needed one ATS.

The concrete pad and propane feed from the tank can support up to a 30-35 KW unit. If in the future, 20 KW is insufficient, swapping out a 20 for a 30 or 35 is a heck of a lot easier than rewiring, pouring new concrete and running new propane lines.
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"


PhoenixDown
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reply to pandora

Pandora -- what are your electric rates?



cdru
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Fort Wayne, IN
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reply to nunya

said by nunya:

It's because of the split service. Have you seen the price of the $400A transfer switch?

No I didn't know the price of a 400 amp compared to two 200 amp. A real quick check I found a Generac 200 amp for $600 and Generac 400 amp for $1829. Slightly more than 3x the price, but you save some of the costs by not having twice the work to do. Plus a simpler setup. After factoring in everything, and considering this doesn't seem to be a super low end job, I just would have thought a single ATS would have been the way to go.

pandora
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reply to PhoenixDown

said by PhoenixDown:

Pandora -- what are your electric rates?

The bill is complex, some costs are fixed, transmission is separate from generation. However, it's about 17 cents per KWh.
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"

pandora
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1 edit
reply to nunya

said by nunya:

There's nothing to get hyped up about.
The OP has what everybody incorrectly refers to as a 400A service. It looks fine. They did a nice job (I wouldn't have used SEU on a nice new install like that).

It's really a 320A service, and TBQFH he'll never use it. That transformer on the pole looks to be a 50 KVA, or at the most a 75 KVA. Add to that it is shared with other homes. There *really* isn't 320A even available to the OP.

The utility appears to have provided the service drop. The utility is subject to the NESC, not the NEC. They can pretty much put whatever they feel like in there. Remember, utility work is usually done under engineering supervision. They know that drop will never *really* even see 275A. I doubt it ever sees 200A.

Service size ≠ what's actually available from the utility.

I spoke with the utility today, their belief is the system as installed can maintain 320 amp continuous service. Loads of up to 400 amps may be sustained for long periods (according to the regional installation supervisor). He indicated if at any time, there was a failure to supply 400 amp by the cable or transformer, excluding emergency periods where there are blackouts or brownouts, the electric company is required by law to remediate the service to provide the required load (up to 400 amps sustained).

He indicated the design for all residential 400 amp service assumes no more than 320 amps drawn continuously (he said this is required by state regulation as the minimum the utility must provide).

The wire is 350 kcmil Alcan XLPE 90C, whatever that means. The transformer is 75 KW and feeds 6 homes. When built, all homes in the neighborhood had 75 or 100 amp service. Most now have 200 amp. Street voltage is 8,000 volts to the "main feed" (sometimes he used the word primary apparently interchangeably). Output read with no load to our meter was 246 volts according to the supervisor. I am not at all an expert on these things. He indicated the load was buried approximately 3' underground, with a tracer wire. My electrician had a spare conduit built, in the event there is ever a failure (as the conduit will be paved over by a long driveway).

I don't know if this helps the discussion any, but it occurred to me to ask the people who installed the stuff.

He indicated the street was not scheduled for any upgrade in the near or intermediate future, but that some poles may be replaced, and mine was on the list for an intermediate future replacement. So the pole in the pictures may be a slight concern to the company.

The supervisor indicated while the shunt is installed, they must assume the average use of all homes using the same transformer. He indicated this would save me money, as my use is more than 50% above average.
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"


Jack_in_VA
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The transformer is 75 KW and feeds 6 homes. When built, all homes in the neighborhood had 75 or 100 amp service. Most now have 200 amp.

If all the other 5 crank up their usage to 200 amp that's 1000 amp which is 600 above what you say the POCO says they can supply.

Something about this setup doesn't make sense


Draiman
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reply to pandora

said by pandora:

said by PhoenixDown:

Pandora -- what are your electric rates?

The bill is complex, some costs are fixed, transmission is separate from generation. However, it's about 17 cents per KWh.

It's nice to see the Northeast is consistent on one thing. It's about 17 cents per Kwh here in the Boston area as well.
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pandora
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reply to Jack_in_VA

said by Jack_in_VA:

If all the other 5 crank up their usage to 200 amp that's 1000 amp which is 600 above what you say the POCO says they can supply.

Something about this setup doesn't make sense

How utilities manage and calculate electric loads is beyond my understanding (at this time). It's interesting, but the entire project has been interesting, I've learned a lot.
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"

telco_mtl

join:2012-01-06
reply to Draiman

said by Draiman:

said by pandora:

said by PhoenixDown:

Pandora -- what are your electric rates?

The bill is complex, some costs are fixed, transmission is separate from generation. However, it's about 17 cents per KWh.

It's nice to see the Northeast is consistent on one thing. It's about 17 cents per Kwh here in the Boston area as well.

wow, we are spoiled in quebec, 17 cents is our peak rate when you are on a dual rate meter!


fifty nine

join:2002-09-25
Sussex, NJ
kudos:2
reply to Draiman

said by Draiman:

said by pandora:

said by PhoenixDown:

Pandora -- what are your electric rates?

The bill is complex, some costs are fixed, transmission is separate from generation. However, it's about 17 cents per KWh.

It's nice to see the Northeast is consistent on one thing. It's about 17 cents per Kwh here in the Boston area as well.

I pay $0.1215588/kwh all taxes included in my part of New Jersey. This is because we're on a co-op. On PSE&G when I lived elsewhere in NJ it was about 17 cents per kWh.

Our ETS rate (offpeak, for ETS heating only) is about half the regular rate.

Our co-op opted out of the electric utility competition so we pay just one charge for generation and transmission.


cdru
Go Colts
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join:2003-05-14
Fort Wayne, IN
kudos:7
reply to Jack_in_VA

said by Jack_in_VA:

The transformer is 75 KW and feeds 6 homes. When built, all homes in the neighborhood had 75 or 100 amp service. Most now have 200 amp.

If all the other 5 crank up their usage to 200 amp that's 1000 amp which is 600 above what you say the POCO says they can supply.

Something about this setup doesn't make sense

Even 400 amps doesn't fit a 75 kVA transformer. 240 volts * 400 amps = 96 kVA. It would be 125% overloaded at 400 amps alone, not to mention the other 5 homes. And if Pandora's home is needing all 400, it's likely the other homes are also needing a considerable amount of power. That is, unless Pandora is running the grow lights operation supplying the other 5 homes.

I think that guaranteed 400 amps of continuous service is shared among all the users of the transformers, meaning Pandora's house is likely never to have 400 amps available just to him.

pandora
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reply to telco_mtl

said by telco_mtl:

wow, we are spoiled in quebec, 17 cents is our peak rate when you are on a dual rate meter!

Just one rate. Regardless of time of day.
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"

telco_mtl

join:2012-01-06

us in quebec its around 5 cents for the normal user and dual energy users like myself its abit over 4 cents normally and 17 cents during peak (colder than -15 celcius)



Draiman
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reply to pandora

It breaks down to about 8.5 cents a Kwh for delivery and another 8.5 cents per Kwh for supplier for a total cost of 17 cents per Kwh fixed no matter what here. Then they have a surcharge they add if you exceed 1,000 Kwh a month. That raises the rate to about 20 cents per Kwh for all Kwh's over 1,000.



cdru
Go Colts
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Fort Wayne, IN
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reply to pandora

said by pandora:

The wire is 350 kcmil Alcan XLPE 90C, whatever that means.

350 kcmil means that the wire has a cross sectional area of 350,000 circular mils. A circular mil is an area of a circle 1 mil in diameter. It's an easy way to measure large wires without having to worry about pi. kcmil can also be abbreviated as MCM (M = thousand CM = circular mil) and is usually found for wire gauges larger than 4/0 or 0000 and AWG is used for smaller wires. Take the square root of the kcmils to get the diameter in mils (thousandths of an inch). So √350000 = 591.6 mils = approximately .592 inches in diameter.

Alcan is the manufacture of the wire.

XLPE means Cross-linked polyethelyene plastic insulation. If you're having plumbing done, you may be using the same type of plastic there where it's known as PEX.

90C is the temperature rating on the wire. This go towards how much current a given wire or cable is allowed to carry safely. Common values are 60C, 75C, and 90C. The lower the number, the less current. It also comes into play when you need to derate a cable because of where it's located or how it is ran.


John Galt
Forward, March
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Happy Camp
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reply to pandora

$0.0690 per kW here in Oregon for the first 12,000 kWh, then it drops to $0.0460 for all kWh past that.



nunya
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reply to pandora

That just confirms what I said. A single phase 75 KW transformer can supply *roughly* 320A @ 100% load.
The utility knows that you'll never draw close to that. The chances of everybody turning everything on at the same time and blowing the transformer or the fuse are slim. If it does happen, they deal with it then.
--
If someone refers to herself / himself as a "guru", they probably aren't.



leibold
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Sunnyvale, CA
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reply to cdru

said by cdru:

Even 400 amps doesn't fit a 75 kVA transformer. 240 volts * 400 amps = 96 kVA. It would be 125% overloaded at 400 amps alone, not to mention the other 5 homes.

Technically correct, but not relevant. The 75 kVA rating is the load limit in order to maintain the manufacturer specified service life of the transformer.
Utility companies are well aware that they can far exceed that rating at the expense of a shorter lifespan for the transformer. Given how many pole mounted transformers around here show clear signs of overheating (and how often some of them pop) it appears that our utility company prefers the more frequent replacement to proper sizing of the transformers.
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tschmidt
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said by leibold:

Utility companies are well aware that they can far exceed that rating at the expense of a shorter lifespan for the transformer.

Yup - I can attest to that from first hand experience.

When we built our house installed a 200A service plus 30A separately metered service for hot water. Except for kitchen stove appliances are electric. Even space heating is electric to backup wood stove.

We are 600 feet off the road so have our own pole pig. Power company installed a 10 KW transformer. Being the good engineer that I am felt obligated to point out that 200A x 240V is 48 KW. The supervisor smiled knowingly and said that was true but transformer has tremendous overload capacity. If we were able to overload it they would be happy to replace it.

Well that was 30+ years, a direct lightning strike, and two kids ago and the transformer is still going strong. It will probably still be there after I'm in the ground.

/tom

pandora
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reply to Draiman

said by Draiman:

It breaks down to about 8.5 cents a Kwh for delivery and another 8.5 cents per Kwh for supplier for a total cost of 17 cents per Kwh fixed no matter what here. Then they have a surcharge they add if you exceed 1,000 Kwh a month. That raises the rate to about 20 cents per Kwh for all Kwh's over 1,000.

I'd be in trouble with a 1,000 Kwh limit. Fortunately that doesn't exist in Connecticut (yet).
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"

pandora
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reply to pandora

Tomorrow the first of 2 new 4 ton 18 SEER Goodman heat pumps is going to go live.

Would anyone mind if I snapped some shots and started a new thread about that?
--
"If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand." - Milton Friedman"



Draiman
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reply to pandora

said by pandora:

said by Draiman:

It breaks down to about 8.5 cents a Kwh for delivery and another 8.5 cents per Kwh for supplier for a total cost of 17 cents per Kwh fixed no matter what here. Then they have a surcharge they add if you exceed 1,000 Kwh a month. That raises the rate to about 20 cents per Kwh for all Kwh's over 1,000.

I'd be in trouble with a 1,000 Kwh limit. Fortunately that doesn't exist in Connecticut (yet).

It's not a limit just an escalator to make people pay more for what they deem 'excessive' usage. I'm sure if Massachusetts can get away with it the other states won't be far behind.
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hitachi369
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Grand Rapids, MI
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MI, or at least my energy provider, has a bump at 600 Kwh.


pandora
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reply to Draiman

said by Draiman:

It's not a limit just an escalator to make people pay more for what they deem 'excessive' usage. I'm sure if Massachusetts can get away with it the other states won't be far behind.

My electric bill runs anywhere from 2,500 to 3,000 Kwh per month, depending on season and activity in the home. That's before we increase the size of our home.

Shouldn't the limit vary by home size and number of people residing in it?
--
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Draiman
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said by pandora:

said by Draiman:

It's not a limit just an escalator to make people pay more for what they deem 'excessive' usage. I'm sure if Massachusetts can get away with it the other states won't be far behind.

My electric bill runs anywhere from 2,500 to 3,000 Kwh per month, depending on season and activity in the home. That's before we increase the size of our home.

Shouldn't the limit vary by home size and number of people residing in it?

I think it should be as well. Why should a 2 bedroom condo and a 4 bedroom house be held to the same standard after all. I guess they figure if you can use more then 1,000 Kwh then you can afford the extra 3 cents a Kwh too.
--
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