VFD Motor Load Reactor
VFD Motor Load Reactor
(OP)
For a 3ph, 5hp, 460V, motor a 1000ft from its VFD what do you suggest for protection from standing wave issues, a reactor?
For a line/load reactor (from MTE) I'm seeing numbers like $800!!!
Do I want a Line/Load reactor, or a sine wave motor protection filter? Or, a DV/DT Motor protection filter?
You can't just use an input reactor on the output can you?
For a line/load reactor (from MTE) I'm seeing numbers like $800!!!
Do I want a Line/Load reactor, or a sine wave motor protection filter? Or, a DV/DT Motor protection filter?
You can't just use an input reactor on the output can you?
Keith Cress
kcress - http://www.flaminsystems.com





RE: VFD Motor Load Reactor
You might check with these guys also:
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I'm pretty sure you don't need a sine wave filter. The DV/DT is the concern for long output leads.
AFAIK, the output reactors are pretty similar to the input reactors.
But I'm sure the experts will be along shortly.....
Dave
RE: VFD Motor Load Reactor
RE: VFD Motor Load Reactor
It seems a lot of reactor makers are saying that theirs can be applied to the input OR the output, calling them input/output reactors.
Of course I think I'd be fighting the dV/dT fight in this case which they don't seem to mention with the exception of MTE who makes "dV/dT filters". Which mysteriously enough, weight exactly the same 74lbs as the input/output reactors. Me thinks this is whole thing is just an exercise in label swapping.. :)
Keith Cress
kcress - http://www.flaminsystems.com
RE: VFD Motor Load Reactor
For 5hp, 460V, 1000ft, and an MG1 P31 motor, I would expect a sine filter would be required. I have application data from MTE and TCI and, if I'm reading it right, that's the judgement from both.
1000ft motor leads is simply extreme length on a drive and, yes, the sine filter generally will cost about as much as the drive.
RE: VFD Motor Load Reactor
RE: VFD Motor Load Reactor
The only difference is a set of filter components (essentially snubber circuit) on a PC board, adds no weight.
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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RE: VFD Motor Load Reactor
I'm going to have them re-evaluate a DOL installation. Barring that, they need to go with the Full Monty $$$.
jraef; Thanks for that detail.
I learned something here, Thanks all.
Keith Cress
kcress - http://www.flaminsystems.com
RE: VFD Motor Load Reactor
Nah, you just need a bigger hole or longer fingers....
I once did work in developing a submersible VFD for a company in Oregon called Selectric who made one that did fit down the hole with the motor. All they had coming back up the pipe was the power leads and a comm link for the operator interface. One of those great ideas in theory, not terribly practical in reality.
RE: VFD Motor Load Reactor
You need to communicate with the drive using carrier current so you don't need a highly problematic little cable for it, which has to add fragility and cost.
The VFD could be insanely small with the inherent water cooling.
Lets do it. :)
Keith Cress
kcress - http://www.flaminsystems.com
RE: VFD Motor Load Reactor
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: VFD Motor Load Reactor
Do not forget the voltage drop in the reactor/filter. It is an often missed factor and can lead to increased current demand if not factored in.
RE: VFD Motor Load Reactor
Neil