Dyno Operation Control Problem
Dyno Operation Control Problem
(OP)
Friend has a new Dyno unit (device that measures HP of auto). It has a 20 amp 220 volt main feed and a seperate 120 volt control unit feed. Unit works properly with a generator but not from the utility feed. This is at his house in the country so has a utility pole transformer with a 200 amp feed. The dyno is in another building a with a 100 amp main panel (4 wire feed from service enterance panel). Initial operation had diodes blowing on the control boards. Current problem is "warbeling" at certain speeds. At just below 50%, unit is pulling 7.5 amps, but between 50 - 65% is varies between 7 - 12 amps and is unstable. Once it gets above 65%, current levels back out to 10 amps. Turning on and off other breakers in the panels does effect at what point this "warbeling" takes place. Utility company has looked at the problem with no solution found. Equipment manufacture has no similar problems so states "unit works fine in 1000 other installations". Several people have suggested that he install a isolation transformer. Been working on this for over a month and justs wants to get the unit running correctly. Any suggestions on things to try or test?





RE: Dyno Operation Control Problem
RE: Dyno Operation Control Problem
RE: Dyno Operation Control Problem
http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?u...
Any suggestions??
RE: Dyno Operation Control Problem
Any suggestions on things to try or test?
///Even though the current around 12A may seem to look sufficiently low, the branch circuit, #14AWG or its IEC equivalent, 16Amps or 10Amps may experience noticeable voltage drop that affects the dyno performance. Also, the voltage waveform should be checked for its pure sinusoidal quality.\\\
RE: Dyno Operation Control Problem
Did have a Oscope on the feed line. Waveform kind of looked like a chair with the back to the left. Not very sinusoidal. Only found this waveform with the Dyno running.
RE: Dyno Operation Control Problem
The bad connection could be from the dyno to the box or from the box to the pole.
RE: Dyno Operation Control Problem
Is it normal for the unloaded leg to raise the voltage?
Don't know what the overall load on the system was during the testing. Other testing showed the max draw over 2 days was 60 amps per line so not working the 200 amp service very hard.
RE: Dyno Operation Control Problem
If the full drop in voltage on one leg adds to the opposite leg, then the neutral feed is creating the full voltage drop, so it has significantly more resistance than the other wires (probably poor connection at the transformer).
With only a 20amp load on 200amp serv I can't imagine seeing even a noticeable drop in voltage on the loaded side (4 volts seems like a lot). Imagine how unbalanced the voltage would be if you had a large load on one side.
It doesn't have to be much resistance to cause a problem, just a few tenths of an ohm.
RE: Dyno Operation Control Problem