200 amp 700 feet

[ActionDave]

ActionDave and PtonSparky,

Because neither of you wouldn't use Zbang's Xfmr idea doesn't mean it can't be done?

Regards, Phil Corso

Of course it can be done, the question is would it be the economical way to go.

Exactly. By the time I pay for and wire the trannys and disconnects at both ends I can by a lot of wire.

 

[Phil Corso]

Of course it can be done, the question is would it be the economical way to go.

Iwire... then I apologize if you have already "Priced" it ! If so, could you at least hint at what the cable-method savings was, in %?

Phil

 

[iwire]

Iwire... then I apologize if you have already "Priced" it ! If so, could you at least hint at what the cable-method savings was, in %?

Phil

I have not.

But this is about a home, not a commercial / industrial set up, that being the case there is a large advantage at keeping things simple.

As I said in one of my earlier posts, if they really need 200 amps of capacity at less than 3% drop transformers are going to start looking very good.

On the other hand if this is a typical home with low power needs and not much reason to hold to 3% you can likely save some money by forgetting the transformers.

Just the cost to do a quality, long lasting transformer installation at the service point is going to be costly.

 

[dfmischler]

And the PoCo is just not interested in dropping a transformer 50 feet from the house? Even if you dig the trench and bury their cable in sand under their supervision? Or is the price to do it that way just too high?

 

[truck41trouble]

And the PoCo is just not interested in dropping a transformer 50 feet from the house? Even if you dig the trench and bury their cable in sand under their supervision? Or is the price to do it that way just too high?

+1 on this. Is the power company at all willing to come up say 500-600 feet? Then youll have a marginal run of secondary cable. Primary wire for a single phase wye systems fed underground, may save you a buck or two. Even overhead primaries would do the job.
800' is a long way for 120/240.

Sent from my VS987 using Tapatalk

 

[kwired]

I would have to turn everything on at one time to get 150 amps and before long the range or oven would be cycling. The water, garage and house all cold with heat pump and well on.

In reality it will never see a 100 amps. We are 2k+ Sq ft with a full basement, all electric.

I have similar sized house and loads, plus my shop is also supplied by the same meter. I would guess it never sees 100 amps either, if it does it is very short in duration.

Exactly. By the time I pay for and wire the trannys and disconnects at both ends I can by a lot of wire.

Especially aluminum wire. I would probably parallel 4/0 aluminum to OP's application without even doing any calculations. His load will probably seldom exceed 100 amps, he will have voltage sags when HVAC compressor or any other larger motor starts, and the increased conductor size probably helps with that more then any general voltage drop issues. Of course before I did that I would be seeing if we can get the source closer to the load.

 

[ptonsparky]

Internet cost of a 50KVA 1Ph 480 to 240/120 transformer is $1690. The POCO may be able to set a 15 or 25 KVA for this service but we can't. Secondary or primary taps would be best but I did not look for that option. Cost of 3R 600V disconnect with 150A fuses is $500. POCO needs to supply 480V single phase and Main Breaker in house panel would have to be used as Secondary protection. You can buy a lot of wire for $2200.

Add for transformer slab, additional conduit work and another 200A fused disconnect if one is required at POCO demark.

 

[JDB3]

And the PoCo is just not interested in dropping a transformer 50 feet from the house? Even if you dig the trench and bury their cable in sand under their supervision? Or is the price to do it that way just too high?

The PoCo, stops at the road. Period, they don't budge.

 

[JDB3]

+1 on this. Is the power company at all willing to come up say 500-600 feet? Then youll have a marginal run of secondary cable. Primary wire for a single phase wye systems fed underground, may save you a buck or two. Even overhead primaries would do the job.
800' is a long way for 120/240.

Sent from my VS987 using Tapatalk

Everything in this sub-division is underground.

 

[Cow]

At 700', it will be hard to beat pvc and aluminum wire for this project. No transformers. What would really work slick, would be Cable-In-Conduit. Finding it in the right size and a potential long lead time might be a nonstarter though.

 

[ptonsparky]

The pivot guys stock it here and they can put it in quicker than I can line up materials. They are not dealing with lots of rock either. No body likes to cut the spool though, they are typically 1/4 mile runs.

 

[JDB3]

At 700', it will be hard to beat pvc and aluminum wire for this project. No transformers. What would really work slick, would be Cable-In-Conduit. Finding it in the right size and a potential long lead time might be a nonstarter though.

I had forgot about that. :slaphead: Have to see what the supply houses have to say on that matter. AND get it OKed by owner & general contractor (since he is use to doing it the old way).

 

[Cow]

The pivot guys stock it here and they can put it in quicker than I can line up materials. They are not dealing with lots of rock either. No body likes to cut the spool though, they are typically 1/4 mile runs.

Yeah, a lot of the reels we get for circles(1.25-2" usually) are usually better than 2000' or so. But, I just ordered some reels of 3" HDPE last week and it's coming on 1000' reels. So, 700' might be close to a full reel in the size he's looking at. It's worth a 5 minute phone call to see.

 

[Dzboyce]

Cow,

do do you buy it from Irrigation Components in Pasco? They're the only place I know of that stocks it.

 

[Cow]

Cow,

do do you buy it from Irrigation Components in Pasco? They're the only place I know of that stocks it.

I'm not sure which product you're asking about?

We get Cable-Con from Elmers Irrigation in Hermiston, OR. I wasn't the one purchasing it for the projects we've used it on, so I can't tell you if it's a stock item or not. You could contact Wish NW, they are the distributor for a lot of cable con, they will give you a vendors list of businesses you can purchase from.

We get HDPE from General Pacific in Fairview, OR.

 

[electrofelon]

I have similar sized house and loads, plus my shop is also supplied by the same meter. I would guess it never sees 100 amps either, if it does it is very short in duration.

Especially aluminum wire. I would probably parallel 4/0 aluminum to OP's application without even doing any calculations. His load will probably seldom exceed 100 amps, he will have voltage sags when HVAC compressor or any other larger motor starts, and the increased conductor size probably helps with that more then any general voltage drop issues. Of course before I did that I would be seeing if we can get the source closer to the load.

I agree. My rule of thumb for a typical house is to use 70 amps for the max load - that will even cover electric range, electric domestic water, and electric dryer. I have done tests and not been able to get it over that amount. Sure, add in a bunch of electric heat, big heat pump/AC, on demand H20, you could easily get higher. Using that 70 amp figure, 400 Al keeps VD under 3%. Id probably go with 350 URD in PVC (because I think it is the biggest size URD they make and single conductors are a little more $). Parallel 4/0 would do it too. Also agree CIC would be awesome if available.

 

[kwired]

I tried the CIC a few times for irrigation, think it is still the cat's meow for a center pivot with the control panel 1/2 mile away on the adjacent quarter section of land where the well is, but for 75 - 100 HP well supply around 1/4 mile long I found it to be a bigger hassle then the traditional URD cable in DB conduit. If you have right equipment it maybe is the way to go though. Otherwise you do need a decent sized tele-handler, loader, maybe a boom truck (with more then just a bucket for a person to work from) just to handle the reel. On top of that the closest supplier for me (that has a big enough inventory that they are likely to have it on hand) is about 120 miles away, and I have to go pick it up. I have one of my regular supply housed that can get it - but they buy it from that same place and take a mark up on it. Both my regular supply houses can deliver the DB conduit and URD to the installation site for no extra charges, along with other items I may need.

 

[ptonsparky]

I tried the CIC a few times for irrigation, think it is still the cat's meow for a center pivot with the control panel 1/2 mile away on the adjacent quarter section of land where the well is, but for 75 - 100 HP well supply around 1/4 mile long I found it to be a bigger hassle then the traditional URD cable in DB conduit. If you have right equipment it maybe is the way to go though. Otherwise you do need a decent sized tele-handler, loader, maybe a boom truck (with more then just a bucket for a person to work from) just to handle the reel. On top of that the closest supplier for me (that has a big enough inventory that they are likely to have it on hand) is about 120 miles away, and I have to go pick it up. I have one of my regular supply housed that can get it - but they buy it from that same place and take a mark up on it. Both my regular supply houses can deliver the DB conduit and URD to the installation site for no extra charges, along with other items I may need.

I let them deliver it and help unload the truck one stick at a time as they drive across the field. Generally, the CC is buried before I know anything about a project. I consider myself lucky if the PP isn't laying there next to the well motor.

 

[PVfarmer]

1

The best that I determined is 500 KCmil Al.

So you are shooting for 5%?

2

given a 700' run of 500 AL I get the following results

11.87% drop @ 200 amps

I'm confused- do you mean 11.87 volts/ just under 5% of 240V?

3

If you load is truly 200 amps, running 1000 MCM aluminum would get you down to about 5.4% voltage drop along the 1000 MCM conductors.

Same there, do you mean 5.4 volts, and not 5.4% of 240V which is 12.96V? 5.4 volts would be a 2.25% drop on 240V.

I'm using Mike Holt's equation here.
I=(CM×VD)÷(2×KxD)
K= 21.2 for aluminum.

I=(CM×VD)÷(2 ×21.2 ohms×700ft)=XXX Amps
VD= (240*.05) = 5% is 12V.

#1 - So (500,000 x 12V) / 29680 = 202 amps.

#2 - And 500,000 x 11.87V / 29680 = 199.96 amps.

#3- While 5.4 % of 240V is 12.96V.
So 1,000,000 *12.96 /29680 = 436 amps, that seems like double what is needed.

Am I right here?
Say 500 feet of 2AWG copper, 480 3 phase, if you want 3% VD, 3% = 83 amps?

(2AWG * 3%VD) / (1.732*12.9*500)= 83A
or
(61631 * 14.4) / (1.732*12.9*500)= 83A

Don't Let Voltage Drop Get Your System Down
http://ecmweb.com/code-basics/dont-let-voltage-drop-get-your-system-down

 

[iwire]

1


I'm confused- do you mean 11.87 volts/ just under 5% of 240V?

Good catch, I screwed up transcribing the info from my voltage drop app.

It should have been 11.87 volts dropped and 4.95%