Siemens Masterdrive Problems

If it runs fine in v/f mode then it may be that the drive has lost the motor tuning parameters for vector mode. Check the port and starboard drives to ensure that the motor parameters are the same. Any of the parameters that the auto-tune fills in may be at fault. If you are able, do an auto-tune (automatic motor identification) on the port drive.

If you have had so many visits and problems, I would advise you to try and find someone who, by references etc, really knows what he's looking at and doing.

The symptoms reflect seemingly different issues, the stuttering start may be Vector calculation errors but this really wouldn't explain hardware problems you've experienced. The DC Caps failing shows either overheat, too high a load or too much ripple (AC) if the components themselves are not faulty.

you don't what the incoming power source is (generator, DC bank) and how this was checked since the supply is not easy to analyse without high spec instruments but I guess the other drive (no problems at all??) is on the same so the problem may be sourced from the drive itself. The other issues sound like they are connected to the drive control supply. so, all in all, these issues are not obviously related!

The whole issue sounds to me like faint friend syndrome where you don't know whether the drive, supply or advice is reliable - you need to eliminate to get to the real reason - a good person is paramount for this, in my experience.

I'm no big fan of Siemens' drives it must be said, having heard many horror experiences over years but this doesn't mean this is necessarily the case without good reason to think so. Having said this, a swapout would obviously see if the problem remains or follows the drive. Where in the world are you?

Good Luck

The boat is currently located in Port Fourchon, La, USA. It was discovered today that if he incresed the sampling time from 6 hz to 12 hz, the drive would run (not well, But it would run) so they are currently trying to figure out what is going on with the feedback circuit that would caus it to have issues at the lower speed. We have had at least 3 different companies here to look at it and currently have 3 Siemens Reps onboard trying to figure out the problem. I personally think it is just a hunk of crap that we are going to be stuck with. The incoming voltage was analysed by the manufacturers of the generators and deemed to be fine. This thing has cost us not telling how much money in Technicians and lost revenue. If we ever figure out the problem I will post it here to let others who may experience this problem know where to turn to.

u hv had many persons look at the problem. very good so far.

from what you describe i contend that this is not originally a drive hardward problem at all.

i presume that you have siemens product experts looking at it - i feel it is better that siemens have application and system engineers look at it - they have fine application engineers here in India at their offices at Kharghar near Mumbai. i suggest that the problem be referred to the guys at Kharghar.

I would check all the grounds ---

First of all, I would like to thank everyone for their help, the problem has been resloved(we believe). For those of you in the future who have a similiar problem, it was the Current transducer on one of the phase leads in the inverter slave cabinet.

Replaced the CT and the drive is up and running. (until something else brakes anyway)

Thanks again for all you help!