Tom Jenkins
Lifetime Supporting Member
In another thread Dick DV mentioned voltage drop through line reactors, which of course means there is a power loss as well.
In the wastewater industry I routinely encounter engineers whou specify both line and load side reactors, usually at the highest rating optionally available. (For example, if hte manufacturer's standard input line reactor is 3% but a 5% is available, they will spec the 5%). This is partly because they aren't paying for the equipment, and partly because they don't realize that the improvement (sometimes marginal at best) in transient protection and harmonics comes with an energy penalty.
I have never seen specific power losses for line reactors. Since these are inductors I assume VxA isn't accurate. Some suppliers have suggested that a 3% reactor will result in a power loss of 3% of the motor power, but this seems too simple. Making the analysis more complicated is the fact that much of the time the motor load is significantly less than nameplate. Finally, most VFDs claim a power factor of 95% or better - what is the impact of line reacors on the power factor?
I'm sure the answer is not simple, but any guidance would be appreciated.
Tom
In the wastewater industry I routinely encounter engineers whou specify both line and load side reactors, usually at the highest rating optionally available. (For example, if hte manufacturer's standard input line reactor is 3% but a 5% is available, they will spec the 5%). This is partly because they aren't paying for the equipment, and partly because they don't realize that the improvement (sometimes marginal at best) in transient protection and harmonics comes with an energy penalty.
I have never seen specific power losses for line reactors. Since these are inductors I assume VxA isn't accurate. Some suppliers have suggested that a 3% reactor will result in a power loss of 3% of the motor power, but this seems too simple. Making the analysis more complicated is the fact that much of the time the motor load is significantly less than nameplate. Finally, most VFDs claim a power factor of 95% or better - what is the impact of line reacors on the power factor?
I'm sure the answer is not simple, but any guidance would be appreciated.
Tom