Eng-Tips is the largest forum for Engineering Professionals on the Internet.

Members share and learn making Eng-Tips Forums the best source of engineering information on the Internet!

Register Log in
  • Congratulations dmapguru on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. singapore11singapore

    DC Motor and Drive

    Hi All, I have a two DC motor application; the motors are mechanically coupled. They are driven by 2 DC drives; one each. One of the motors has had its armature rewound. Now when I run this motor up with the DC drive I get to around 50% load and begin to hear loud humming...it doesn't trip as...
  2. singapore11singapore

    Can DC drives be run without a tacho input?

    Hi, If this is a new motor you must do the autotuning......standstill and rotating, which will automatically include the PID adjustment you are talking about. You cannot use the previous values..and you may need to de-tune the PID a bit, as it will be tuned only to suit the drive and not so much...
  3. singapore11singapore

    Siemens MV Softstart

    Hi You are correct; based on the keypad and control module, the 81000TM is actually a Solcon HRVS-DN.
  4. singapore11singapore

    Siemens MV Softstart

    Good Morning Guys, A quick question: Do Siemens still make a MV softstart? The 81000?? And who is the third party who this softstarter is really from??.....Motortronics of something? I remember a number of years ago going to Thailand to fix a "Siemens/Motortronics softstart....but I have just...
  5. singapore11singapore

    rc filter and insulation monitor

    Hi, Have removed the earth from the RC and now find another....on all the drives on the cranes. See attachment, I remove the armature feedback cable as shown byred arrow and no more earth faults. With all other cables removed apart from the armature feedback, the earth fault is still present...
  6. singapore11singapore

    rc filter and insulation monitor

    Hi, I.m not sure of the effect of having this ground point now floating will have. I will have a look (google it)! What if anything are the negative effects. Regards S11S
  7. singapore11singapore

    rc filter and insulation monitor

    Hi, And the final drawing I have
  8. singapore11singapore

    rc filter and insulation monitor

    Hi, For insulation meter see attached. This is pink line coming from the left comes from the delta transformer three phase supply...tapped off to feed a single phase transformer for this supply. There is no ground anywhere on this 600:230Vac control transformer.
  9. singapore11singapore

    rc filter and insulation monitor

    Hi All, There is no sign in any drawings of CT's for the DRM - I will be at site tomorrow and will physically/visually check. The delta supply transformer is attached. I like the idea of just removing the resistors and leaving the capacitors. I will try that.
  10. singapore11singapore

    rc filter and insulation monitor

    Hi, So the transformer feed is 45MVA....in the heart of the vessel. To change it would be mind boggling in time, money - therefore it will not be changed - so they WILL be going with an IT system. Removing this RC discharge network is very easy and basically no cost - and best of all for the CE...
  11. singapore11singapore

    rc filter and insulation monitor

    Hi, Seen the three phase transformer secondary - clearly a delta winding - no fourth wire or ground. I have tried to attach the rc network drawing. Basically three phase R in parallel with C...three times for each phase. One side is connected to a lone phase of the 3 phase the other side of...
  12. singapore11singapore

    rc filter and insulation monitor

    Hi, The transformer feeding this is a delta delta, primary/secondary. I believe that is the issue - it is an IT ungrounded circuit...with this RC to ground causing an issue with the insulation meter being low.
  13. singapore11singapore

    rc filter and insulation monitor

    Hi it is a DRM 96-N I understand that the system is actually ungrounded.....and they have grounded the noise filter. I will check back up the line to the main transformer....see if it a star point secondary....and if starpoint is not connected. If like this....I can remove this noise filter and...
  14. singapore11singapore

    rc filter and insulation monitor

    Hi, I have an RC filter across the three phase......R in parallel with C x 3 times on one side...all three connected to ground the other.. Connected to the same three phase I have an insulation meter. I can confirm that when the three phase filter is isolated from the circuit, that the...
  15. singapore11singapore

    Siemens 6RA70

    Hi Lukin 1977 Checked all, and it was your item 4. As I mentioned, I am in closed loop feedback without any encoder/tacho, so field weakening was a no-no. My motor was running only at 1100 rpm, and not 1500 rpm. I slightly lowered the field current and the speed slightly increased.....to a...
  16. singapore11singapore

    VFD Harmonic Filter over-temperature or fan failure?

    Hi, I recently had some Schneider drives running some fans with a Schaffner filter also continuously give a temp alarm...even when I heat gun the units it is clear that the temp is fine. Think there is an issue with the firmware on the Schaffner units
  17. singapore11singapore

    Siemens 6RA70

    Hi, I have installed a Simoreg DC Master 6RA70 to a motor. It is running forward/reverse/jog etc.....no problem. However, the speed is slightly slow...90%, and I have maxed out the pot. Therefore is there a parameter wrong in my setup? There was no mention of the field current on the motor...
  18. singapore11singapore

    VFD Motor Parameter Auto-Identification

    Hi, We initially found the same.....so left the temp at default value....but only later when testing on our test bed we found that inputting the correct temp value gave us smoother reactions during running. Therefore, in our case....a drilling application, we call the chair and ask them what...
  19. singapore11singapore

    VFD Motor Parameter Auto-Identification

    Hi, When you do a standstill rotation one of the parameters to set is the motor temp...P652 "motor ambient temp"...it is very important you tell it the correct value, as this has a huge effect on the calculated values. The four spikes you see towards the end of the rotational test....is caused...
  20. singapore11singapore

    Old DC Motor Field Specs wanted

    Hi, what is shown is the armature current and voltage......what would the field current and voltage be?? there is no separate nameplate showing this....

Part and Inventory Search

Back
Top