Line reactors are installed between your VFD and the power source.
They protect the VFD.
Load reactors are installed between your VFD and your motor. They protect the motor.
To explain this, picture a bath tub. The water represents the electricity. The waves in the bath tub represent the movement of the electricity as a sine wave. One end of the bath tub is your motor and the other is the VFD.
Variable frequency drives (VFDs) do not output constant power. At the micro level, they create pulses of electricity. When you zoom out, all of those little pulses look like a consistant sine wave that you would expect to see.
Electricity flows as a sine wave down the wires. Every pulse of electricity creates a ripple of electricity. Those little waves can bounce off the walls and travel in the opposite direction.
In the bath tub, if the little waves are created at just the right time, they add together to become bigger waves. Eventually, those big waves will become too big and water will splash out of the tub.
When electricity cannot be absorbed, it will bounce and start traveling the opposite direction. The height of the wave is called the amplitude, or amperage for electricity specifically. Electrical wires are rated for a maximum amount of amperage. If the amperage exceeds this then the electricity will "spill" out of the wire by burning holes in the wire's insulation.
The biggest waves occur when the wave hits a wall, which in our example, would be your motor or the VFD. If the wave is too large when it hits your motor, it will burn holes in the motor's electrical windings. Eventually, this will cause the motor to internally short out.
A reactor inhibits large waves from forming. With no large waves, your motor will be safe.
If there is a long distance between your VFD and motor then you should use a reactor. The longer the distance, the larger the harmonic waves will become. Generally, if there is over 100 feet of wire between the VFD and the motor then you should install a load reactor. Some motors can handle up to 300 feet of wire if they meet the NEMA MG-1 Part 31 standard.
If your input power is prone to having spikes then installing a line reactor will smooth out that spike to help protect your VFD. If you have multiple VFDs connected to the same power source then adding a line reactor in front of each one of them will prevent "cross talk" between the drives.
If a motor is not inverter rated then you need to use a load reactor. A VFD doesn't produce a clean sine wave. The average of its output is a sine wave but it's actually made up of many small electrical pulses. If a motor is not inverter rated then these pulses can burn small holes in the insulation of the motor's windings. Putting a reactor between the VFD and the motor will smooth out these electrical pulses and will make it much more of a true sine wave. If your motor's nameplate does not say that it is inverter rated, then you should use a reactor to protect it.
Lenze published a recommendation on when to use a reactor. This publication can be found here.
The size of the reactor is based on the size of the VFD. If the VFD is rated for 10 horsepower, then you will need a reactor that is also rated for 10 horsepower. Below is a sizing chart to determine which reactor you need based on the horsepower of your VFD. The line reactor should be the same size as the load reactor.
|208 volts||240 volts||480 volts||600 volts|
Talk to one of our Journeymen ElectriciansContact Us
We would be happy to help.
We can also pre-program the VFD before we ship it to you.
Awesome sales and even better after sales service. I highly recommend Electram!
- Brent Electrical Contractor
You can actually talk to people who know what they are doing, didn't oversell, shipped everything quickly.
Fantastic experience. I took a long time to decide but they were always there to answer all my questions. Can only recommend Electram
- Juerg Owner of Woodworking Shop
I bought a unit from these guys last year. Excellent service,above and beyond! I was in a jam needed it in a hurry and they got to me here in B.C. Quick response and very knowledgeable would buy from them in a heartbeat.
- Jody Business owner
The team at Electram benefits from having an incredibly diverse set of skills, and is organized in a way to produce nothing but the best. Everything that goes out the door is checked and rechecked, quality control is outstanding, and they have a wealth of knowledge that they take the time to share with anyone who asks. Highly recommend.
- Jake Electrical Contracor
Ron and the team at Electram provide outstanding customer services and high quality products. I would highly recommend them to other electrical contractors, engineers, or anyone needing their services. Very satisfied and hope to work with them again soon.
- Jesse Owner of Woodworking Shop
Electram was extremely patient with all my questions and very very knowledgeable. Very happy to have found them.
- Tamara Small Business Owner
I purchased a used Electram phase converter on Craigslist and needed help with the connections. The Staff at Electram responded to my emails and phone call immediately and were very helpful answering all of my questions, getting my phase converter up and running quickly. Great customer service. They even has all of the original specs and info on my exact converter.
- Mark Small Business Owner
Thank you for intense service and parts delivery. You people were knowledgeable, patient and helpful. From ordering parts at 4 pm EST and receiving them the next day by noon, not once but 3 times! Absolutely amazing. And a special thanks to Ron as we were troubleshooting a very tricky application. Our customer was very happy and impressed.
- Tony Owner of Orser Technical Services
Fantastic technical and sales support. Really highly recommend these guys!
© Copyright 2021, Electam | All Rights Reserved.