600 yard to pump

[Another C10]

Is it ever possible or practical to draw the water from the customer's water line with an inline water pump using check valves. Just a wild thought.

 

[__dan]

I like the idea of the boost only transformer and letting the VD take up the extra. It is within my comfort zone, meaning even if hokey my opinion would be it's legal and safe. Supply nameplate voltage at the motor terminals, +- 10% of nameplate is usually OK, with max efficiency right at nameplate

Since it's non standard I would spell it out in writing to the owner and have him sign off on it as a money saving variance. I would say he has to give informed consent, then I would not worry about it coming back to me years later.

As Jon says, typical autotransformer boost only carries a fraction of the kVA for sizing the transformer. Typical secondaries are 12 / 24 and 16 / 32, so the 32 V boost at 12 A is 384 VA or a .5 kVA autotransformer. I have a basement full of those, I save the takeouts.

Autotransformer could be either end but boosting at the service end would have a higher Voltage and less current through the run length (marginally), while boosting at the load side, autotransformer could easily be after the pressure switch saving the idle winding heating (also very marginal). Probably a wash unless the run time is a lot, then boost the service side.

The no egc, I don't see a way around 250.4 (3). Only exception I could see would be entirely non conductive enclosure apparatus /equipment, no exposed metal, which I assume does not apply. It has to have an egc afaik.

System reliability and reduced repairs over the long term is a key factor. Any downtime for service and repairs will quickly eat up any savings from the various install methods. The drive would be fragile in that regard. The autotransformer would be indestructible.

That type of run, I believe they make a product the conductor is already in the pipe on a reel.

 

[Joethemechanic]

it ever possible or practical to draw the water from the customer's water line with an inline water pump using check valves. Just a wild thought.

The practical limit for suction head is about 20 feet. In theory you can go to like 30 ish feet depending on barometric pressure and temperature of the water. But rule of thumb is if you are trying to pull water up more than 20 feet you need to redesign (place the pump lower)

 

[mtnelect]

How about setting your own poles with "Tri Plex" service cable ?

 

[Barbqranch]

Regarding a 480 volt 3 phase pump, if it fails, there might be a much longer delay to get a replacement. Also an additional cost of replacing the pump is pulling it from the well, which could be expensive.

 

[zbang]

How about setting your own poles with "Tri Plex" service cable ?

Probably need a specific permit or easement to cross the state road. Add potential maintenance hassles and underground starts to look really attractive.

 

[PaulMmn]

How deep is the well?
You've got a well house, but that appears to be at the customer's premises. What's at the well head?

 

[AC\DC]

If I said well that’s my bad it’s on the local lake. My dad has water rights and we lost power. Diver found a Beaver attached to the line. Says there is miles of Unsed wires in the lake and splices all over. I will not let my kids swim there is a death trap

 

[ptonsparky]

If I said well that’s my bad it’s on the local lake. My dad has water rights and we lost power. Diver found a Beaver attached to the line. Says there is miles of Unsed wires in the lake and splices all over. I will not let my kids swim there is a death trap

Those dang little details. (insert sadly shaking head emoji)
Not that it changed your wire size dilemma.

 

[hillbilly1]

If I said well that’s my bad it’s on the local lake. My dad has water rights and we lost power. Diver found a Beaver attached to the line. Says there is miles of Unsed wires in the lake and splices all over. I will not let my kids swim there is a death trap

Ahh! So that’s why you’re adamant about the gfi! Seeing the whole picture now! 480 would not be a good solution then.

 

[AC\DC]

Sorry I did say well house Opps

 

[AC\DC]

Now owner is only doing 400 feet of boring and trenching the other 1600 feet lol. I told him to lay that direct buried tray cable( or UF pricing them out) and put a under ground pull box at the end of the 400 feet of boring, to tie into. He wants conduit for future with pull points every 500 feet. I like that less labor for me on that pull lol.

 

[tortuga]

There is no code specifying voltage drop. Do you have a local rule?

In Oregon, as well as CA and WA there is an energy code that covers voltage drop, its not in the NEC and enforcement is spotty.
Usually on very long runs.
Also from reading others posts on here it seems a majority of states now have voltage drop in the energy code..
When I have been called on it it was an expensive fix, so once bitten twice shy.

Oregon Energy code
90.1-2019
Section 8 – 8.4.1
Voltage Drop

Two types of conductors
• Feeder conductors
– Connect service equipment to the branch circuit breaker panels
• Branch circuit conductors
– Run from the final circuit breaker to the outlet or load
Feeder conductors and branch circuits combined to be sized
for a maximum of 5% voltage drop total

State of Oregon: Energy in Oregon - Energy Code & the Built Environment

www.oregon.gov

 

[AC\DC]

Regardless of voltage drop don’t we have to supply proper voltage that manufacturers state on equipment?
They give you a +\- on motors but we have to meet that

 

[tortuga]

When I was dealing with inspectors and voltage drop they cited ANSI C84-1 @Jraef has a sticky post on here explaining it. If I had to go 2000 feet I would probably bump up to 480 or 600V. There are single phase pumps for 480. Up in Canada 600/300 single phase is pretty common for long runs to pumps. Dan had a good suggestion on using a VFD.
Forget GFCI on a run that long, at that distance a EGC probably meaningless anyways, an earth reference is 1800 - 200' away and 25 ohms at 0 feet is meaningless.
There are ground fault relays you can use, utilities and municipalities use them all the time for long lighting runs, such as a bike or jogging path.

https://selinc.com/products/321/

Not cheap though.

 

[tortuga]

Why would you have a well pump so far away ? Please educate me.

Fresh water is getting harder to find.

 

[hillbilly1]

Fresh water is getting harder to find.

From the sounds of this, it is probably for landscape irrigation, it is quite common on lakes here in Georgia. Where city water is available, permits for wells are usually denied, and it gets expensive to water lawns with city water, as sewer expenses are rolled into it. If it is a body of water that is also used for recreation, I can see the OP’s concern for ground fault protection. I quoted a desalinator for a house in the Caymen’s many years ago. Very expensive to water the lawn there, and salt water from the ocean would kill the grass.

 

[electrofelon]

In Oregon, as well as CA and WA there is an energy code that covers voltage drop, its not in the NEC and enforcement is spotty.
Usually on very long runs.
Also from reading others posts on here it seems a majority of states now have voltage drop in the energy code..
When I have been called on it it was an expensive fix, so once bitten twice shy.

True. Probably preaching to the choir here, but The big flaw with practically all of these is what current value do you use? If you use the rating of the ocpd at the beginning of the branch circuit or feeder that's going to be ridiculously over conservative and WASTING energy on unnecessary extra materials.

I work in Washington (mostly Seattle). And the enforcement of their energy code is indeed spotty. Typically on commercial projects the basic stuff will be enforced like occupancy sensors and controlled outlets in offices. Interestingly, labor and industries inspectors, which are the state inspectors which inspect areas outside of most cities which do their own, do not enforce the Washington energy code. Apparently the legislature passed the energy code as law but never specified who was in charge of enforcing it. So L&I hasn't been told to enforce it so they're not enforcing it.

 

[tortuga]

True. Probably preaching to the choir here, but The big flaw with practically all of these is what current value do you use?

I use the actual load, with no NEC adjustments since its not a NEC calc.
I was waiting for you to suggest one of your 2kv feeder's.

 

[electrofelon]

I use the actual load, with no NEC adjustments since its not a NEC calc.
I was waiting for you to suggest one of your 2kv feeder's.

I thought about that, but probably it's not far enough or a big enough load to justify it. At 2kv All one would need is two runs of #14 2kv PV wire and 3/4 PVC conduit so big savings on materials, but the custom transformers are going to be pricey. I would guess 3k each. With 5% drop assuming 10 amps @ 240v is only #2 AL. Of course with the transformers you can use the grounded conductor as the bonding conductor so you only need two conductors instead of three but it just doesn't seem like we're in the realm of step up / step down transformers being worth it.