Reactor and EMC filters
Reactor and EMC filters
(OP)
Are line reactors and EMC filters placed at the input of VFD serving the same purpose? We are OEM. Machines that we make have incoming 3 phase power - line reactor - EMC filter - VFD (3HP or 5HP Unidrive SP by Control Technique). Most likely we would need to have EMC filter because these machines have CE label. I am wondering if we are able to remove line reactor from this chain.
Any input?
Any input?





RE: Reactor and EMC filters
Unlike a thyristor controller, a frequency inverter doesn't need line reactors to operate safely.
Gunnar Englund
www.gke.org
RE: Reactor and EMC filters
RE: Reactor and EMC filters
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I don't suffer from insanity. I enjoy it...
RE: Reactor and EMC filters
PaulBr.
RE: Reactor and EMC filters
I agree with Gunnar and CJCPE - unless you have to meet harmonic limitations then you shouldn't need the reactor. Some very large drives need line reactors to reduce the peak current drawn by the rectifier, but not at 5HP.
I do think you may fall foul of the harmonics limitation regs in Europe at this power level. Europe has slowly been tightening the requirements on harmonic-producing loads: check out IEC 61000-3-2 : 2000. I'm not hugely familiar with this standard because it was published after I left the power electonics sector, but it should help you work out what you need in place for the European market.
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I don't suffer from insanity. I enjoy it...
RE: Reactor and EMC filters
RE: Reactor and EMC filters
If you are exporting into Europe, you need to ensure that you install the drives in the manner for which they have been tested to gain the CE mark. If the CE testing and certification was done with both the EMC filters and line reactors, then you need to use both in order to comply with the CE certification. If the testing was only done with an EMC filter, then that is all you need to comply.
Note: there a major differences between EMC filters, you need to use the type specified in the documentation.
The AC line reactor can have an influence on the EMC performance, so if it was in place in the original testing, you need to use the correct type.
Some VFDs include internal inductors in the DC circuit. These serve a similar purpose to the AC line reactors in reducing the level of harmonics in the supply (reducing distortion power factor). If there are DC chokes within the drive, the advantages of the AC line reactors are reduced.
Best regards,
Mark Empson
http://www.lmphotonics.com