Thoughts on Adding VFD to Multi Motor Machine
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This came up not too long ago and I decided to put something together that
one can consider as an option. This would be my approach if I had to do it for my machine. I will be happy to help if someone wants to pursue this and have questions. Just keep in mind that my availability depends upon what I got going on. Imran |
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Excellent plan and advice.? Thanks Imran.??
Down in the nuts and bolts of the application, remember to think about heat and ventilation.? This is especially true if you plan to use dynamic braking.? I mention this because I saw overheated VFD's? at 3 separate locations this week and the ad hoc solution was the same every time.? This picture shows an Allen Bradley 1386 VFD driving 10 each 20-hp motors.? The enclosure is located in a steam valve room above a lumber dry kiln.? It was over 100f in there on an 80F ambient day. The yellow tape was a nice touch and a nod to both the safety and production managers.? |
¿ªÔÆÌåÓýThanks Jonathan. I know you were thinking along the same lines, as far as the high level mechanization is concerned. Wow, my VFD max ambient spec is 104F so these guys are really pushing it. There is a lot to consider when wiring VFD as it is a high frequency noise generator. That is the penalty for the electrical efficiency VFDs achieve when compared to the pure analog voltage output of PhasePerfect. So while there are many precautions in routing the power to the VFD some of them may be more of a CYA or more applicable to larger units than what most of us will have in the shop. Also, it is a receiver issue, not a VFD concern. So if you don¡¯t have sensitive electronics noise generated by the VFD is less of a concern. As an example, all of my AC cables run on ?2.5¡± wide ledge on top of the block foundation. This ?is covered by an inverted L shape baseboard. Since I do my own wiring, I ran my VFD power cable in the same ¡°conduit¡± to see if it would cause any issues. None have come up over 6+ yrs, so I have left it as is. I am inputting single phase so the input current is higher than it would be with 3 phase input. It is 7.5HP VFD running a 5.3HP RL125. I do NOT suggest this if you hire an electrician. In that case follow the VFD wiring guidelines. However, if you are doing your own work, then you can try, as I did. If it works still be aware that if you add a sensitive equipment later you may have to redo your work. It just depends upon the situation. Imran Malik On Jun 29, 2022, at 3:29 PM, Jonathan Smith <jonathan.smith@...> wrote:
?Excellent plan and advice.? Thanks Imran.?? Down in the nuts and bolts of the application, remember to think about heat and ventilation.? This is especially true if you plan to use dynamic braking.? I mention this because I saw overheated VFD's? at 3 separate locations this week and the ad hoc solution was the same every time.? This picture shows an Allen Bradley 1386 VFD driving 10 each 20-hp motors.? The enclosure is located in a steam valve room above a lumber dry kiln.? It was over 100f in there on an 80F ambient day. The yellow tape was a nice touch and a nod to both the safety and production managers.? |
imran
Jonathan Smith