Reactor Rating 3

[backer86]

I am trying to find the rating of a reactor connected to a medium voltage system for fault current calculations. the reactor has specs as follows:

Reactor connected to a 4.16KV bus
300A
Z = 6%

 

[waross]

Two points:

The percent notation was originally used to represent the voltage drop of a transformer when fully loaded. It still is, and is recognized as Uk in percent on most transformer nameplates.

The regulation describes the voltage drop of a transformer at full load. The impedance describes the operation with the terminals shorted.

The same notation is used for reactors. A 2 or 4 % commutation reactor, for example. Or, in your case, a 6 % reactor, which simply means that you will have a 6 % voltage drop across the reactor when current is 300 A.

Yes, if you neglect the resistance, which it is probably safe to do. But the 6% voltage drop at full load current will be almost at right angles to the voltage of a resistive load and will have little effect on the load voltage. If I did the math right, a 6% reactive voltage drop will drop the voltage across a resistive load less than 0.2%
I was responding to the use of impedance percentages to calculate voltage drops under normal operating conditions.
Transformer and reactor impedances describe short circuit conditions when the impedance is the total circuit.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[pie314]

The Z= 6% Simply means the maximum short circuit current is

100/6 = 16.67 times normal = 300*16.67 = 5000 amps

Also it means the reactor is rated .48 ohms

2400 volts/.48 = 5000 amps