ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Recent Posts
GFCI's pops in large numbers
by dsk - 10/21/21 02:03 AM
Need some info on Japanese outlets, 200V 15A
by andey - 10/20/21 08:05 AM
Wire sizing
by watersparkfalls - 10/19/21 07:27 AM
nec 110.3 (B)
by watersparkfalls - 10/19/21 07:09 AM
A 5-20(20a) receptacle is legal on a 15a circuit?
by libellis - 10/10/21 12:46 PM
New in the Gallery:
240/208 to a house
240/208 to a house
by wa2ise, October 9
Now you know.
Now you know.
by Tom_Horne, September 7
Who's Online Now
0 members (), 8 guests, and 17 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#203186 09/13/11 08:32 PM
Joined: Oct 2001
Posts: 172
I need an expert or someone with a working knowledge of phase generators. I have phase convertor that runs a small piece of equipment with 3 three phase motors. The problem is a 5hp fan motor is going out on overload. I believe the problem is in the convertor but I am not sure. The single phase 240v supply to the convertor is good. The no load voltages at the convertor are A=122v B=122V C=196v AB=244v BC=210v AC=206v. The currents at the 5hp fan motor are A=2.9 B=20.2 C=13.1 under this load the voltages are AB=240 BC=196 AC=206 Anyone have any ideas or suggestions to determine the actual problem. They would be more than welcomed

Joined: Nov 2005
Posts: 826
You should probably supply info on the type of converter that you are using.

Joined: Oct 2001
Posts: 172
it is a rotary converter that has been in service for a couple of years.

Joined: Jul 2004
Posts: 783
When you open up the converter, it has a bunch of canned power capacitors, correct? If so, my GUESS is that you have some bad capacitors. Look for the ones that are swelled or really hot.

Did you have some recent power outages or local lightning strikes? Those caps are AC rated electrolytics. Make sure if they need to be replaced, that you pay attention to the voltage ratings. If I remember right, they were typically rated for 600 VAC.

Joined: Oct 2001
Posts: 172
Yes there are capacitors inside the starter enclosure. I will check those , thanks.

Joined: Oct 2001
Posts: 172
Thanks Larry, it was the capacitors. Both run capacitors were bad and when replaced the B phase current fell drastically.

Joined: Jun 2004
Posts: 1,273
Not withstanding their higher price -- you're better off with Run Caps...

They're made to MUCH higher standards.


Link Copied to Clipboard

Tools for Electricians
Tools for Electricians

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Posts: 421
Joined: September 2005
Top Posters(30 Days)
dsk 6
Popular Topics(Views)
284,715 Are you busy
217,341 Re: Forum
203,693 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5