Author Topic: Low voltage  (Read 10424 times)

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Low voltage
« on: August 20, 2006, 06:36:58 PM »
Hi I 've been running my 20k head for the last 2 hours or so. I checked the volts and hz with a Kill-a-watt meter and I am getting 204 volts at 60.5hz  17 amps load.
I am under the impression there is resister that can be adjusted to vary the voltage in relation to the hz.  I don't see it. where could it be? I checked the slip rings, they are clean.
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #1 on: August 20, 2006, 10:00:36 PM »
HEre it gets interesting. 
at 57.5 amps the voltage is 107 or 214 59hz
at 0 amps, no load volts       88 or 176 60.5
Dennis
« Last Edit: August 20, 2006, 10:03:26 PM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

Doug

  • Guest
Re: Low voltage
« Reply #2 on: August 20, 2006, 11:43:47 PM »
Can you post me a picture of all the terminals and wiring associated with the field. Maybe I can spot something...

Its hard to give good advice when your not familiar with machine in question but I might be able to see something obvious.

Doug

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #3 on: August 21, 2006, 12:01:33 AM »
Hi It is a power solutions typical st head as far as I know. I suspect the chinese diode pack. I took it out and checked what I could without unsoldering any thing.
Ive just been on Utterpower looking at the manual on line. The gen head did not have any paperwork with it. It had some brushes and a holder.

Its been working OK untill today. When I got it I checked connections and all looked good. The output voltage was what was expected.
I cleaned the slip rings before I fired it the first time.
Ithasn't been overloaded, the 28/2 won't take it.
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

Doug

  • Guest
Re: Low voltage
« Reply #4 on: August 21, 2006, 01:59:52 AM »
Do you have a Multy meter?

If you don't spend a few bucks and read the booklet with it ( get one with a diode check setting ). You can check the bridge easy enough. Forward biased diodes will  drop .5 to .7 of a volt and block the opposite direction. There's nothging else to check, if its showing a short ( less than .5 volt ) or looks like it conducts in both directions its scrap.
I'd like to be more help but until I get my hands on an ST I can't give good advice.

Doug

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #5 on: August 21, 2006, 02:19:24 AM »
Hi George has a trouble shooting manual on utterpower.com for ST heads. I have it but I hav'nt had a chance to work through this process yet.
Thanks
Dennis
« Last Edit: August 21, 2006, 02:24:13 AM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #6 on: August 27, 2006, 07:42:27 PM »
Hi
I finally got a chance to go to radio shack. I bought a Part 276-1185 bridge rectifier. I chose this one because it had standard spade terminals. At $3.29 I will keep a spare.
Peak reverse volt 50v
rectified current   25a
Forward volt drop 1.7v
reverse leakage at PRV 100ua
cost3.29 +tax
The unit is running now at 20Amp at 230
Dennis

The old rectifier is hard to check with the multi meter but I found two that read the same forward and reverse.
« Last Edit: August 27, 2006, 07:47:31 PM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #7 on: August 27, 2006, 08:25:26 PM »
Hi I ran the new rectifier at 20 amps on the gen head for almost 2 hours. The temp on the rectifier was at 116f by infared thermometer. The green paint in the sun was 110.
I jumped the load on the gen head up to 50 amps and the tempt jumped up to 125f in seconds. I will have to build a heat sink to keep it cool.
Dennis
« Last Edit: August 27, 2006, 10:50:43 PM by dkwflight »
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

rsnapper

  • Newbie
  • *
  • Posts: 49
    • View Profile
Re: Low voltage
« Reply #8 on: August 29, 2006, 11:41:21 AM »
Dennis,
I mounted my rectifier on the inside of the generator end plate (like in George's CD) and used some heat conducting gel. I haven't shot it with my pyrometer but there should be plenty of air moving in there to keep it cool. Its also easy to get to.

Glad you got it fixed inexpensively.
Rick

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #9 on: August 29, 2006, 12:48:32 PM »
Hi I ordered a fancy finned heatsink from mouser.com. They have a huge selection of bridge diodes and just about anythin else you could possibly want.
I'll post a pic when I get it mounted.
Thanks
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

xyzer

  • Hero Member
  • *****
  • Posts: 1043
    • View Profile
Re: Low voltage
« Reply #10 on: August 29, 2006, 08:01:12 PM »
While on the issue of bridge rectifiers.....does anyone have a part no. for a replacement on a 5KW ST generator? Or know where I can get one?
Thanks!
 Dave
Vidhata 6/1 portable
Power Solutions portable 6/1
Z482 KUBOTA

dkwflight

  • Hero Member
  • *****
  • Posts: 573
    • View Profile
Re: Low voltage
« Reply #11 on: August 30, 2006, 12:16:22 AM »
Hi I would use the same rectifier from radio shack. I think it will do the job. I  won't heat up as much
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

xyzer

  • Hero Member
  • *****
  • Posts: 1043
    • View Profile
Re: Low voltage
« Reply #12 on: August 30, 2006, 01:20:01 AM »
Dennis
Thanks.....I need a spare one that takes up less room...
Dave
Vidhata 6/1 portable
Power Solutions portable 6/1
Z482 KUBOTA

Joe

  • Sr. Member
  • ****
  • Posts: 253
    • View Profile
Re: Low voltage
« Reply #13 on: August 30, 2006, 03:17:04 AM »
Check ebay etc. for the rectifiers...I got 4 good sized ones (technical term for "I don't remeber the size") for around $10 + shipping.  I color coded the terminals  and the wiring harness they plug into with nail polish so that a quick chageout can be made ...

Joe
Nothing is easy...if it were...anybody could do it.

2005 Power Solutions  6/1-ST5

xyzer

  • Hero Member
  • *****
  • Posts: 1043
    • View Profile
Re: Low voltage
« Reply #14 on: August 30, 2006, 03:28:16 AM »
Guys....I'm a machinist not a "sparkey" I have done lots of wireing 3phase and single......but never a bridge rectifier. I can take it apart and put it back togeather but rectifier values.... ???....I'm in part number land...I did do a e-bay search and found the "archer" one ....but what are the nessary values it has to have?...Radio Shack has em in stock...easy!
« Last Edit: August 30, 2006, 03:35:54 AM by xyzer »
Vidhata 6/1 portable
Power Solutions portable 6/1
Z482 KUBOTA