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...
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...
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...
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...
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
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.
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.
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...
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...
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.
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...
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...
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...
