
auCom soft starters
#1
Posted 07 July 2006 - 02:15 AM
#2
Posted 07 July 2006 - 03:39 AM
Can you please give us more detail. ie model number and a description of load installation etc. Is this unit installed in three wire or six wire connection?
Have you contacted NHP for suport? I assume that you are in Australia.
On first glance, it sounds like the behaviour that you get when one SCR is not being turned ON.
This could be due to a number of factors, but what happened to the last unit? was it returned for service? was there any information on what the problems was?
Please check the control voltage going into the unit. It should either be 240VAC or 415 VAC. What is the actual voltage and what does the voltage do when you try to start? If the control voltage is dropping severely, then it is possible that there may be insufficient energy getting to the firing circuits.
It is also posible that you have a failed pcb which is not controlling one SCR properly.
If the unit is an IMS2, you have three yellow phase indicator LEDs on the left hand side of the panel. These glow at full brightness when the power is ON but the SCRs are not conducting. As the output voltage is increased, the LEDs get dimmer and extinguish at full output. If you watch these LEDs during a start, you can see which phase is not behaving.
You can also exchange the pcb for another one and see if the problem stays or goes away.
Another trick is to replace the motor with three 100 watt 240 volt lamps connected in star across the motor terminals. These will also give you an idea of what is hapeneing with the starter during start. All three lamps should be the same brightness during the start.
Best regards,
Mark Empson | administrator
Skype Contact = markempson | phone +64 274 363 067
LMPForum | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters
#3
Posted 07 July 2006 - 06:59 AM
I am in Australia and have always found the support provided by NHP to be pretty good. Have you spoken with the Product Manager?
Regards,
GGOSS
#4
Posted 08 July 2006 - 03:31 PM
#5
Posted 08 July 2006 - 03:47 PM
#6
Posted 08 July 2006 - 04:03 PM
yes one of our engineers did speak to them and the suspect fault starter, but what would be actual cause of it. we also have recently installed some sinuspenta VFD supplied by NHP and its been a lot of trouble on one application. actually we had the NHP engineers on site to install for the first time. whenever the conveyor is fully loaded and is stopped for some reason, it would start at all. we have played around with few of the parameters but still not very good , as we had to deramp the preceeding conveyor a lot faster when there was a stop. this results in gaps in material and is not very good for quality tracking. we have spoken to NHP and there answer is that it could either be in speed control mode or torque control. speed control is critical to us as there is whole lot of other things synchronised with the conveyor but we also need the starting torque as well. the motor is only 75 KW with nominal current of 130 A but the VFD is capable of supplying 290 Amps for at least 2 minutes in every 20 minutes in need be. any suggestions.
#7
Posted 08 July 2006 - 09:03 PM
It might be better and more clear if you start a new thread on the SinusPenta VFD application. It can get confusing to people who read these threads later on for help if you are mixing applications, especially if they happen to be the same size as these two seem to be.
#8
Posted 09 July 2006 - 11:10 PM
It should not make any difference whether you use 240 volt control or 415 volt control provided that the voltage remains within limits and is correctly connected.
To have two failures, EMX followed by IMS2 so soon after, suggests that there is something common outside of the starters that is causing the problems. I think that I would be verifying the control voltage initially.
Best regards,
Mark Empson | administrator
Skype Contact = markempson | phone +64 274 363 067
LMPForum | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters
#9
Posted 09 July 2006 - 11:36 PM
I would agree with Marke re 240 / 415VAC control, this should not make a difference. In fact I would suggest 240VAC would be better.
With the EMX and IMS soft starters it is important that the control supply remains within specification. If this reduces by 25 - 30% during motor starting, it is possible that SCR missfiring will occur. This may have something to do with what you are experiencing at the momment.
More details would allow the members of this forum to guide you further.
Regards,
GGOSS
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