RailPro > RailPro Specific Help & Discussion

Motor over peak current

(1/2) > >>

atsfguy:
 After conducting the Full Motor Current test and measuring 610 mah, I had a caution icon appear on my screen indicating my motor had checked as “motor over peak current”.
  I checked Ring’s website hoping to find an error message explanation but did not. Is it drawing too much current?
  I have read of one locomotive belonging to a member drawing over 700 mah. What is the cut-off on current draw?
  BTW, this is on an Athearn blue box GP-7 that is about 35 years of age with few running hours.
  Thank you for your replies.
Cheers,
Cecil

G8B4Life:
Never seen anyone report that one appearing before, but the error message does exist. As for not finding anything about it on Ring's site, we'll just add it to the list of everything else that other manufacturers can publish about their systems but Ring can't.

My guess is that the motor tries to draw more than 2A at startup; ie it consumes 610mA running but to get it started takes more than the peak output of the LM, which is 2A. It may even report this at over 1A which is the continuous rating for an LM. This is all just speculation of course but I imagine that if the motor was drawing more than the Full Motor Current Test it would simply show Motor Overload and not Over Peak Current as the error message.

It might pay to give the motor and drive train a good going over if you haven't done so. I know Kevin has done a few installs with old Athearn motors so hopefully he might drop in with some hints for running RP with old Athearn motors.

I wonder if I could simulate my guess somehow, you've peaked my curiosity.

- Tim

William Brillinger:
My first question would be: is your software up to date on the LM and the HC?

Alan:
Current through a non-moving armature is determined solely by the resistance of its windings and the brushes. The current draw of a spinning motor is always less than that of a stationary armature because of BEMF. The current draw everyone sees on their HC is a spinning armature. A non-moving motor typically allows far more current to flow than an LM can handle however, because the motor starts spinning almost immediately, the LM doesn't shut down or report error. On a scope you can see the initial spike. Can't see it on a voltmeter because it is so brief. I have measured ultra-brief spikes in excess of 5 amps on an LM equipped Atlas HO loco.

I am guessing your GP-7 has a tight or binding drivetrain causing the motor to be hesitant to begin spinning. The LM can handle a very brief high amp spike. It can't handle a spike that lasts longer.

atsfguy:
Alan, the me hanism moved very freely prior to placing the motor/ gear train in place.
Bill, in a telephone conversation a week ago with Tim Ring, he told me to update the LM after setting Full Motor Current. Why, I don’t know.
I will update the LM today and retry running.
Thanks for your help.
Cheers,
Cecil

Navigation

[0] Message Index

[#] Next page