ideas for testing 50Hz motor at 60Hz

[foretmark]

3 HP singlephase 220v 50Hz motor

Only have 208v 1 & 3ph and 480v 3ph available (280 L-N).

Doing the math for the motor, I get a V/Hz of 4.4. I get 3.5 for the 208/60. My load is a hydraulic pump, charging a vessel that shuts off at a set pressure.

To test this, I only need to run it for short periods (under a minute) but frequently start/stop it.

Obviously I'd like to get closer to the V/Hz tolerance but am not sure how. I don't think I want to put 280v (277) on a 220v motor, and I don't know of a singlephase VFD...

any ideas?

 

[itsmoked]

Use a single boost type, dry transformer found at any electrical supply house. We use them all the time to get away from that yucky 208V and back up where motors were meant to soar.

These are auto transformers and so don't need to carry the full motor kVA only the boosted portion.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Follow the chart:
208 in 240 out. This will get your V/Hz happier.

http://www.acmepowerdist.com/r.asp?URL=/pdf/Page_111-114.pdf

From here:

http://www.acmepowerdist.com/products.asp?PAGE=/selguide/index.aspx

Keith Cress
kcress -

http://www.flaminsystems.com

 

[foretmark]

thanks Keith! hey I think your link is dead....tried from work and home (different pc, link, etc..) adn both failed...

 

[jraef]

Chances are really good that your motor is capable of being connected in Y for operating on a 380V system. The V/Hz would then be the same as a 460V 60hz supply (7.6), which you say you have available (you have 480V, but close enough to work within the motor's tolerance). The motor will run faster though. You should also read Keith's FAQ on this subject as well.

faq237-1224


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[waross]

I have used 220 V 50 Hz motors on 277/480 volts 60 Hz with no problems.
220 x 6/5 = 264 volts. Plus 10% = 290 volts. No problem at 277/480 volts.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

foretmark; Thanks for the heads up on my link. My site went down because I changed email companies and my credit card date expired.

They sent warnings to the dead email..

They promised it would be back up tomorrow.. We shall see.

Keith Cress
kcress -

http://www.flaminsystems.com