# 830y480 / 796y460



## ppsh (Jan 2, 2014)

I've read this is a common voltage in the oilfields. I cant seem to find what is used for fusing. Everything seems to jump from 600vac to medium voltage. 

I was thinking it would be a decent solution doing a step up step down for some of the well pumps runs I've had to to at 3000+ ft. It's a decent bump over 600v, but able to use off the shelf 480-240 transformers in a wye bank.

Most all xhhw-2 is now 1kv rated, just unsure of what's available for cost effective ocpds.


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## micromind (Aug 11, 2007)

If the PUCO will hook it up, it'd be great. 

The few systems I've seen use basic 600 volt fused disconnects. The idea is if it's a solidly grounded Y, there would be 480 to ground and phase-to-phase would be a series rating. I don't know if basic 600 volt fuses are listed for series or not.............

If they won't handle phase-to-phase in series, it'd put a whole new meaning to 'blow a fuse'.......lol.


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## ppsh (Jan 2, 2014)

micromind said:


> If the PUCO will hook it up, it'd be great.
> 
> The few systems I've seen use basic 600 volt fused disconnects. The idea is if it's a solidly grounded Y, there would be 480 to ground and phase-to-phase would be a series rating. I don't know if basic 600 volt fuses are listed for series or not.............
> 
> If they won't handle phase-to-phase in series, it'd put a whole new meaning to 'blow a fuse'.......lol.


I doubt PG&E would even supply it. Hard enough getting a 2nd service at a single address. It's mostly just far runs out to submersible pumps no bigger than 7.5hp, along with a service receptacle.
Have been doing 240/600 step up step down transformer setups for them.


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## wcord (Jan 23, 2011)

830 or 796???
Is this something new


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## SWDweller (Dec 9, 2020)

"Everything seems to jump from 600vac to medium voltage"

I must not get out enough these days. Medium voltage starts at 1000v. We used to have a lot of 2100v stuff and still do on some pumping applications. Mostly fed from generators out in the middle of no where. They use single phase equipment and use a rope tied to the back of your truck to get these spinning before you close in the starter. Stuff scares me.

Mostly all of the voltages have move up one notch around here. What was 2100v is now 4160v. In the mines all of the cables and equipment is 15kv rated so it does not matter where you put it. Adjust the overloads and your in business. Miners like other groups can be a bit dense at times.


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## emtnut (Mar 1, 2015)

ppsh said:


> I've read this is a common voltage in the oilfields. I cant seem to find what is used for fusing. Everything seems to jump from 600vac to medium voltage.
> 
> I was thinking it would be a decent solution doing a step up step down for some of the well pumps runs I've had to to at 3000+ ft. It's a decent bump over 600v, but able to use off the shelf 480-240 transformers in a wye bank.
> 
> Most all xhhw-2 is now 1kv rated, just unsure of what's available for cost effective ocpds.


Haven't heard of it either, so I did a google to see if it was a thing ...

This thread came up, the guy in post #23 refers to oilfields usage.
Didn't read the thread, so not sure if it's helpful or not.






480 Volt Single Phase


480/830v 3ph yielding 480 L-N is used in mining and petroleum fields. Could it be used for street lights to where each pole would get 480v L-N, but the ground feeder carries 480/830 wye?



forums.mikeholt.com


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## micromind (Aug 11, 2007)

wcord said:


> 830 or 796???
> Is this something new


It's been around for many years. 

If 3 480volt transformers are connected Y, you'll have 480 to neutral and 831 phase-to-phase. A motor will be 796.

A basic 12 lead motor can be connected for 796, just connect it as a series Y. The lines go on 1,2,3; 4&7, 5&8 and 6&9 splice and 10,11 and 12 splice. The result is 3 460 volt coils connected Y. 460 x 1.732 = 796


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## wcord (Jan 23, 2011)

Interesting.
is that voltage mentioned in your NEC?
What disconnect and fusing can you use as everything we use is rated max 600v


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## micromind (Aug 11, 2007)

wcord said:


> Interesting.
> is that voltage mentioned in your NEC?
> What disconnect and fusing can you use as everything we use is rated max 600v


I looked it up in the NEC, in the definitions part it states that Voltage, of a circuit, is the greatest difference between any 2 conductors. 

This means that a 600 volt device is not ok to use on a 480/831 system. 

Sort of an old memory but I'm pretty sure I saw basic 600 volt stuff on the 480/831 systems I've seen.


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## JRaef (Mar 23, 2009)

Weg makes motors that are 762/440V, I was told by the Weg salesman that it's because the 762V (nominal 830V) is used in remote mining operations in Brazil for trailing underground mining machinery (to help with voltage drop). It confused the crap out of me once because we got a 500HP Weg "Mining Duty" motor in for a crusher once and saw that it was "dual voltage", so assuming it was 460/230V, my guy connected it for the higher voltage. The crusher ran, but had no torque and would stall on us. After a couple of hours, I finally looked more carefully at the nameplate and saw that the motor was 762V Y / 440V Delta, so for 460 we had to connect it as LOW voltage. Solved the problem, but up to that point I had never heard of 830V nominal as a distribution voltage. That was about 25 years ago now. I've looked on-line for references to Brazil using that voltage and have never found confirmation of what that Weg salesman told me.Still, I've seen the Weg mining motor LV/HV connection confusion issue discussed elsewhere over the years.


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## paulengr (Oct 8, 2017)

Toshiba also winds them with the LV configuration as 460 but they don’t label the HV configuration. MOST motors follow the IEC/NEMA standard wiring diagrams but a few deviate.


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## micromind (Aug 11, 2007)

It's been about 15 years but I remember a vertical impactor rock crusher that had 2 300HP Weg motors that belt-drove a common shaft. They were labelled 460 volts and had the parallel ∆ (low voltage) connection.


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