2200V Motors

[stidwell]

This may seem like a simple question to most, but i have never come across this senario before...

A client requested we use 2200VAC motors on a well field expansion that is under design. Here is the situation

Incoming Power Transformer: 13.2kV - 277/480VAC, 3PH, 4W

MCC/Motor Starting: 480VAC, 3PH, 4W

After the motor feeders leave the MCC the voltage is boosted to 2200V and then to the motor...

There is no OCPD or Fault Current Protection on the Secondary side of the 480V - 2200V tranformer....

I am confused if this is still a viable option? Seems ineffiecient and confusing...

Any help or further explanation would be greatly appreciated.

Thanks in Advance.

 

[eric9822]

First question I would ask is "why"?

 

[LarryFine]

First question I would ask is "why"?

First guess: long motor circuit.

What's the motor HP?

 

[zog]

First question I would ask is "why"?

First guess, found a "cheap deal" on some 2200V motors in the used market, most likely from overseas.

 

[Jraef]

This is very common in the high HP deep well submersible pump market. The arrangement is the standard for companies like Centrilift and Reda pumps. What they will do is design the pump to perform at 2000V, then use a 2200V feed and expect at least 10% drop at the bottom of the well. The transformer windings, just like the motor windings, are protected by the overload relay. Remember, that transformer is dedicated to that single circuit, it is not a branch circuit or a distribution transformer.

 

[eric9822]

Still sounds pretty goofy IMHO.

 

[Besoeker]

Some industries just use specific voltages by convention rather than any technical consideration. Over the years, we have supplied a number of drives for coal mining applications in various parts of the world. They are 1100V. I haven't seen that voltage used anywhere else.

 

[masterinbama]

At first I thought he meant 2400 volts. That voltage was very common in the water treatment distribution industry for quite some time. At least around here.

 

[Jraef]

At first I thought he meant 2400 volts. That voltage was very common in the water treatment distribution industry for quite some time. At least around here.

Deep well submersible pumps use specially designed (long, thin) motors, so they design the windings with the application in mind as well. 2000V or 4000V are the typical design standards, although have seen 1500V on a pump that was in a 4000' deep well where the utility would only deliver 2300V to the site. The voltage drop to the bottom of the well worked out to be about 20%, so they stepped down to 1850V at the top and ended up with 1480 at the motor. It's easier to make a custom transformer than it is to come up with a custom motor voltage design for a one-off job.

 

[stidwell]

First of all thank all of you for your input to my origional post.

Second sorry it has taken me so long to get back to you.

This is a submerible well configuration with HP's between 125 and 250.

Do i need to worry about inrush current and the transformer being able to "ride" it out when the motor starts? what about secondary protection protection on the pump (2200V) side of the transformer?

The wells are between 600 and 1000 ft. deep.

SIDE NOTE.....
Believe it or not the 2200V pumps/motors are actually cheaper when you figure the pigtail of copper needed to get back to the surface. 2200V/250HP motors require #2 AWG 5KV rated wire, where 480V/250HP motors require 500MCM (due to some voltage drop).....thus alot more copper is required.