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to telco_mtl
Re: The renovation continues ... today new 400 amp service!said by telco_mtl:up here 400 amps is pretty common. We have cities that zone for "intergeneration" houses which are basically a 3-4 bedroom house with a bungalow hanging off the side. Since they dont want people buying these and using the bungalow as an income suite they wont let them be separately metered or heated. Since in quebec we are majoritarly heated with electricity a house this big on a single service needs a big entrance. One house i visited with a collegue had an electric forced air furnace heating a 4 bedroom house and a 3 bedroom bungalow attached, the furnace alone called for 150 amps. The bungalow had a 100 amp panel and the 4 bedroom a 200 amp panel. I have a feeling when it gets cold in the winter and that furnace fires up you will get a breeze from the disk on the meter! the disk would prob spin fast enough to be used as a table saw |
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DraimanLet me see those devil horns in the sky join:2012-06-01 Kill Devil Hills, NC 1 edit |
to telco_mtl
I don't see how not allowing people to separate meters stops them from generating income on a bungalow. I'd just include electric in the month fee and rent it out anyways. That or I'd install a TED on the circuits that go to that bungalow and charge them for their usage each month. » www.theenergydetective.com/ |
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ropeguru Premium Member join:2001-01-25 Mechanicsville, VA |
to cdru
said by cdru:said by pandora:My home renovation continues, today was 400 amp underground service install day. You may have two 200 amp panels, but your service wire doesn't appear rated for 400 amps. How did you determine that? |
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Killa200
Premium Member
2012-Dec-5 11:42 am
said by ropeguru:said by cdru:said by pandora:My home renovation continues, today was 400 amp underground service install day. You may have two 200 amp panels, but your service wire doesn't appear rated for 400 amps. How did you determine that? I'm assuming by the 350kcmil marking on the underground feeder wires from the utility. 350kcmil aluminum is rated for 250amp @ the 75c rating, which is more than likely what those terminations are rated for. However, I've not seen service installed for rated around here in a long time. That is a "400amp service", which is really a 320 split phase setup, and that seems like the right amount of underfeed as compared to your typical service feed on 200amp, which the utility around here at least usually runs 2/0 alum. |
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ropeguru Premium Member join:2001-01-25 Mechanicsville, VA |
ropeguru
Premium Member
2012-Dec-5 11:45 am
said by Killa200:I'm assuming by the 350kcmil marking on the underground feeder wires from the utility. 250kcmil aluminum is rated for 250amp @ the 75c rating, which is more than likely what those terminations are rated for. But he was not referencing the terminations. He stated that the service wire was not rated for 400 AMPS. Additionally, would you ever expect one leg of a residential single phase to have to supply a full 400 AMPS? Wouldn't the total be more balanced across both? |
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Killa200
Premium Member
2012-Dec-5 11:50 am
Fixed a typo above and added my thoughts. While he wasn't referring to the terminations, you have to in order to get the correct handling capacity of the feeder run. The wire alone isn't what determines what it can carry, but also what it terminates into.
If you want to focus in the wire alone and in all technicalities, it as well isn't rated for 400 amps, even at 90C.
Do i ever expect 400amps @ 240v worth of load on his service regularly? I have no idea, but it isn't plausible, as if a load calculation pushed him to that point they would have oversized again.
IN technical terms is the service setup as rated? No. But the utility also isn't bound by the NEC, but their own set of guidelines on how to install things. |
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alkizmo join:2007-06-25 Pierrefonds, QC |
to ropeguru
Looks like they used the same type of wire for the overhead (which can be 400A for neutral support overhead). |
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to pandora
Where's nunya when ya need him??? |
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to pandora
Two transfer switches, for two generators? |
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cdruGo Colts MVM join:2003-05-14 Fort Wayne, IN |
to Killa200
I was just going by the wire being stamped 350 kcmil, which by NEC table 310.15(B)(7) seems to indicate a max of 300 amps. I was under the impression that the service wires had to be at least as big as what the combined main disconnects protected to, but maybe not. said by Killa200:But the utility also isn't bound by the NEC, but their own set of guidelines on how to install things. Aren't service entrance cables covered under NEC, but not transmission lines? |
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to Draiman
said by Draiman:I don't see how not allowing people to separate meters stops them from generating income on a bungalow. I'd just include electric in the month fee and rent it out anyways. That or I'd install a TED on the circuits that go to that bungalow and charge them for their usage each month.
»www.theenergydetective.com/ its a deterant, the design of the houses in general is laid out as to complicate division, the 2 units are joined by a door in the basement, the door cannot have any locking device etc. |
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to cdru
said by cdru:Aren't service entrance cables covered under NEC, but not transmission lines? Hmmm, that may be true. I'm going to remit on an answer from that and instead hope whiz or nunya chimes in. |
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ncbill Premium Member join:2007-01-23 Winston Salem, NC |
to pandora
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. said by pandora:My home is now entirely heated by electricity (a Geospring for hot water) and by heat pumps (for hot or cool air). Auxiliary heat requires 20KW per air handler (we have 2 air handlers). The electric heater can draw 4,400 watts, if two are installed (which may happen) I'll need 8,800 watts. |
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DraimanLet me see those devil horns in the sky join:2012-06-01 Kill Devil Hills, NC |
to telco_mtl
said by telco_mtl:said by Draiman:I don't see how not allowing people to separate meters stops them from generating income on a bungalow. I'd just include electric in the month fee and rent it out anyways. That or I'd install a TED on the circuits that go to that bungalow and charge them for their usage each month.
»www.theenergydetective.com/ its a deterant, the design of the houses in general is laid out as to complicate division, the 2 units are joined by a door in the basement, the door cannot have any locking device etc. In Canada they can dictate how you control a door in your own house? That's insane! |
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said by Draiman:said by telco_mtl:said by Draiman:I don't see how not allowing people to separate meters stops them from generating income on a bungalow. I'd just include electric in the month fee and rent it out anyways. That or I'd install a TED on the circuits that go to that bungalow and charge them for their usage each month.
»www.theenergydetective.com/ its a deterant, the design of the houses in general is laid out as to complicate division, the 2 units are joined by a door in the basement, the door cannot have any locking device etc. In Canada they can dictate how you control a door in your own house? That's insane! municipal zoning rule since they are in areas zoned "bi generation" |
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cdruGo Colts MVM join:2003-05-14 Fort Wayne, IN |
to ncbill
said by ncbill:So why didn't you pick a ground source heat pump?
IIRC, those are more efficient for heating than air-source, They are. But for a 5000 square foot house the necessary loop may have been prohibitively expensive in a heating-dominated climate like CT. And you'd still likely want backup heat of some sorts. plus can be configured to provide hot water. It can help supplement, but not necessarily fully replace. Plus in the winter most of the heat is used for heating. You can install an even longer loop for domestic hot water as well, but that adds even more cost. |
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nunyaLXI 483 MVM join:2000-12-23 O Fallon, MO ·Charter
1 recommendation |
to pandora
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. |
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pandora Premium Member join:2001-06-01 Outland |
to fifty nine
said by fifty nine:Two transfer switches, for two generators? Two 200 amp transfer switches for 1 Generac 20 KW. |
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pandora |
to ncbill
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. |
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DKSDamn Kidney Stones
join:2001-03-22 Owen Sound, ON |
to pandora
400A service? Insane. What are you running? A crematorium? It would be unaffordable in Ontario. Most homes have 200 amp service max, even with electric heat. And electric heat is dropping out of favour here. |
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to pandora
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. |
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kherr Premium Member join:2000-09-04 Collinsville, IL |
kherr to DKS
Premium Member
2012-Dec-5 5:21 pm
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. |
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cdruGo Colts MVM join:2003-05-14 Fort Wayne, IN |
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... |
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nunyaLXI 483 MVM join:2000-12-23 O Fallon, MO ·Charter
1 recommendation |
nunya
MVM
2012-Dec-5 5:38 pm
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 Premium Member join:2001-06-01 Outland |
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. |
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pandora |
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. |
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PhoenixDownFIOS is Awesome Premium Member join:2003-06-08 Fresh Meadows, NY |
to pandora
Pandora -- what are your electric rates? |
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cdruGo Colts MVM join:2003-05-14 Fort Wayne, IN |
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. |
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pandora Premium Member join:2001-06-01 Outland |
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. |
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pandora 1 edit |
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. |
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