# line reactor for vfd



## powerblitz (Feb 10, 2013)

I'm installing a 600v 50hp lenze vfd that has no built in filter or disconnect, how do I choose the right line reactor for this drive and can I go without one?


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## HARRY304E (Sep 15, 2010)

powerblitz said:


> I'm installing a 600v 50hp lenze vfd that has no built in filter or disconnect, how do I choose the right line reactor for this drive and can I go without one?


http://www.galco.com/circuit/swreac.htm

I do not know if you can go without one but I hope this helps..




LINE REACTOR SIZING PROCEDURE


Line side of AC or DC Drive

What is the Voltage?
What is the Horsepower of the Drive?
Choosing the Impedance of the Line Reactor

3% impedance reactor will absorb spikes and surges and prevent nuisance tripping of drives in most applications. A 3% impedance line reactor is typical for the line side of a drive.
5% impedance reactor should be chosen if harmonic content is severe or customer wants to minimize harmonics to try to meet IEEE519 recommendations. There should be a note of caution: a voltage drop will occur equal to the impedance of the reactor. Therefore, a 5% reactor will cause a voltage drop of 5%. If your line voltage is low, a 3% impedance line reactor is recommended to minimize the occurrence of a low voltage situation. A 5% impedance line reactor is typical for the load side of a drive.
Select the Proper Line Reactor by using the Selector Chart

Find the Horsepower Rating that you are looking for along the top row of the selector chart (below).
Follow that column down until you meet the voltage/impedance combination you are looking for in the left column of the selector chart.
Reactor part number will be in that box.
Using the Specification Chart in the MTE Selector brochure, verify that the full load amperage of the circuit is within the fundamental range of the line reactor.
Load Side Reactors - AC Drives - (Reactors should not be used on the output of a DC Drive)

What is the Voltage?
What is the Horsepower of the Drive?
What is the motor lead length?
CAUTION - If motor lead length exceeds 15 feet, especially in low horsepower applications, an LC Filter should be considered as an alternative.

Select the Proper Line Reactor by using the Selector Chart (5% impedance is typical)

Find the Horsepower Rating that you are looking for along the top row of the selector chart.
Follow that column down until you meet the voltage you are looking for at 5% impedance in the left column of the selector chart.
Reactor part number will be in that box.
Using the Specification Chart in the Selector brochure, verify that the full load amperage of the circuit is within the fundamental range of the line reactor.


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## glen1971 (Oct 10, 2012)

Call the manufacturer and get their input...


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## JRaef (Mar 23, 2009)

powerblitz said:


> I'm installing a 600v 50hp lenze vfd that has no built in filter or disconnect, how do I choose the right line reactor for this drive and can I go without one?


I would not go without one, especially on a 600V installation, and double especially on a Lenze VFD on a 600V installation. A line reactor is cheap insurance for the drive in helping to protect it from line transients, for example grid switching transients (which are MUCH more common than most people realize) and other things like your next door neighbor's Y-Delta motor starter. As for choosing the "right" reactor, get one that is at the very least 3%, 5% is better, but the higher the impedance, the higher the losses, so think about that too.

The feeling I have on the Lenze part of it, is that a while ago when I worked for a VFD mfr, we were trying to release a low cost low HP 575V VFD, and AC Tech (now Lenze) already had released one. We were having a VERY hard time finding small IPMs, the power modules used in drives, that were rated 600V, so we bought an AC Tech drive and dissected it to see where they were getting them from. What we found was, they were using the exact same IPMs we were using for 480V, so all they were doing was adding some secondary testing at the higher voltage and if they passed, they used them.That means that it is highly likely that they cannot withstand even a SLIGHT amount of over-tolerance on the voltage from the line, so a reactor becomes even MORE necessary.


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## Jlarson (Jun 28, 2009)

Who'd you buy the drive from? They likely can get you the reactors you need. 



JRaef said:


> The feeling I have on the Lenze part of it, is that a while ago when I worked for a VFD mfr, we were trying to release a low cost low HP 575V VFD, and AC Tech (now Lenze) already had released one. We were having a VERY hard time finding small IPMs, the power modules used in drives, that were rated 600V, so we bought an AC Tech drive and dissected it to see where they were getting them from. What we found was, they were using the exact same IPMs we were using for 480V, so all they were doing was adding some secondary testing at the higher voltage and if they passed, they used them.That means that it is highly likely that they cannot withstand even a SLIGHT amount of over-tolerance on the voltage from the line, so a reactor becomes even MORE necessary.


That type of **** scares me. 480 power electronics going boom in the 480 range is bad enough.


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## JRaef (Mar 23, 2009)

Jlarson said:


> That type of **** scares me. 480 power electronics going boom in the 480 range is bad enough.


It's not quite as scary as it sounds. In the power semiconductor world, power device manufacturers like Semikron, Toshiba and Fujitsu don't really make different voltage ratings of devices, they make one batch and test them. So if a mfr has orders for some 600V rated devices, some 480V rated devices and a bunch of 300V rated devices, they take their batch and test them for 300V. All that pass are used to fill the 300V orders first. The remainder are tested for 480V and again, all that pass are sold as 480V. Of the remainder, they test at 600V and any that pass are sold as 600V. Obviously all that fail along the way are waste, that's why they start out filling orders at the lowest level first.

The only thing different that AC Tech was doing was taking the devices they already had bought that had passed at 480 from Semikron, then testing themselves at 600V, rather than wait forSemikron to test at 600V for them, probably because Semikron had too low of a volume prediction for 600V rated devices to bother with. The only thing is, at that point it is not _corroborated _testing, so AC Tech may have been taking "liberties"with their ratings and tolerances, and the temptation would be great for them to do so. I only brought it up as a reason to use a line reactor, again as what I call 'cheap insurance'.


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## John Valdes (May 17, 2007)

One answer. Transcoil!


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## xsryman (Dec 4, 2012)

powerblitz said:


> I'm installing a 600v 50hp lenze vfd that has no built in filter or disconnect, how do I choose the right line reactor for this drive and can I go without one?


 
I would not ever run a VFD with out some kinda of filtering. VFD's put out exactly what they take in. So if you have voltage spikes coming in to the drive it will out put spikes of voltage to the motor that may or may not take it. Or it also may take the abuse for a period of time but ultimatly the spikes could pin hole the insulation in your motor...death by 1000 cuts. Another point to consider is that if the spike is too great it by over charge the DC bus on the drive and blow out the caps then its game over right then and there. check out Trans-Coils KLR line reactors. here is the link to thier selection chart...http://www.transcoil.com/Public/Documents/Pricing/KLR-Price-List.pdf


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## chrish (Apr 12, 2012)

Take a look at Trans-Coil KDR Series. We have been using them for years with our VFDs.


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## tates1882 (Sep 3, 2010)

John Valdes said:


> One answer. Transcoil!


+1. TCI is one of the best. Also like ab brand. 
We usually install line reactors on anything 10hp or more, 3% impedance for normal duty and 5% for hd applications. Also use a load reactor if the motor leads exceed 100-125', note when using both line and load reactors we use 1.5% impedance for a total drop of 3% for the circuit.


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## Nom Deplume (Jul 21, 2013)

chrish said:


> Take a look at Trans-Coil KDR Series. We have been using them for years with our VFDs.





John Valdes said:


> One answer. Transcoil!


I use TCI for all of my line reactors and filters on the VFDs that we install.
Easy to size on their site.
We use the KLR line and the HG7 filters.


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