Linereactor Selection Guide

Line and Load Reactor Buyer's Guide



Why Choose a Line Reactor?


Utilizing variable speed drives to control motor speed has impacted industry both in energy savings and increased efficiencies. The challenge for today's designers is dealing with non-linear wave shapes generated by solid state devices.

By choosing a line reactor, many line problems can be eliminated. Additionally, performance, life expectancy and efficiency of both the motor and the drive itself are significantly enhanced.

Eliminate Nuisance Tripping

Transients due to switching on the utility line and harmonics from the drive system can cause intermittent tripping of circuit breakers. Furthermore, modern switchgear, equipped with solid state trip sensing devices is designed to react to peak current rather than RMS current. As switching transients can peak over 1000 volts, the resulting overvoltage will cause undesirable interruptions. A reactor added to your circuit restricts the surge current by utilizing its inductive characteristics, and therefore eliminates nuisance tripping.

Extend the Life of Switching Components

Due to the attenuation of line disturbances, the life of your solid state devices are extended when protected by the use of a line reactor.

Saturation

Due to the care in the selection of the core material with its optimum flux density, Line reactors will not saturate under the most adverse line conditions. Since the inductance is linear over a broader current range, equipment is protected even in extreme overcurrent circumstances.

Extend the Life of Motor

Line reactors, when selected for the output of your drive, will enhance the waveform and virtually eliminate failures due to output circuit faults. Subsequently, motor operating temperatures are reduced by 10 to 20 degrees and motor noise is reduced due to the removal of some of the high frequency harmonic currents.

Low Heat Dissipation

Particular attention has been focused on the design and field testing of this product line. The result is reactors with ideal operating features including low temperature rises and reduced losses. Reactors will operate efficiently and heat dissipation in your equipment will be of minimal concern.

Minimize Harmonic Distortion

Non-linear current waveforms contain harmonic distortion. By using a line reactor you can limit the inrush current to the rectifier in your drive. The peak current is reduced, the waveform is rounded and harmonic distortion is minimized. Current distortion typically is reduced to 30%.

Severe harmonic current distortion can also cause the system voltage to distort. Often, high peak harmonic current drawn by the drive, causes "flat-topping" of the voltage waveform. Adding a reactor controls the current component, and voltage harmonic distortion is therefore reduced.



harmonic distortion
The total harmonic distortion of variable speed drives produces complex wave shapes such as the phase current shown above. The challenge for today's designers is to effectively minimize these line problems.


Short Circuit Capability

Line reactors can withstand current under short circuit conditions, reducing the potential of severe damage to electronic equipment. In a short circuit, the inductance of the coil is necessary to limit overcurrent after the core has saturated. We have extensive experience in designing and testing dry-type transformers to withstand short circuits for the most demanding applications, and this experience has been applied to line reactor design.

Reduce Line Notching

Whenever AC power is converted to DC by a rectifier using a non-linear device, such as an SCR, the process of commutation occurs. The result is a notch in the voltage waveform. The number of notches is a function of both the number of pulses and the number of SCR’s in the rectifier.

Line reactors are used to provide the inductive reactance needed to reduce notching, which can adversely effect equipment operation.



voltage waveform
A voltage waveform illustrating line notching. Line reactors are used to provide the inductive reactance needed to reduce such notches.


Selection - 3% OR 5% Impedance Reactor

Choose 3% impedance reactors to satisfy most solid state applications in North America. Reactors rated for 3% impedance are ideal for absorbing normal line spikes and motor current surges, and will prevent most nuisance line tripping of circuit protection devices or equipment.


Where considerably higher line disturbances are present, a 5% impedance reactor may be required. Additionally, if the application is overseas, or when it is necessary to comply to IEEE 519, the higher impedance reactor is recommended. These units may also be selected to further reduce harmonic current and frequencies if desirable or to both extend motor life or diminish motor noise.

Line Reactors or Drive Isolation Transformers?

When true line isolation is required, such as limiting short circuit current, or where it is necessary to step up or step down voltage, use a drive isolation transformer. We carry an extensive line of drive isolation transformers in stock.



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Understanding Percent Impedance


Introduction

Drives use semiconductor devices for electrical power conversion. These devices are sensitive to power surges, voltage spikes, current surges, line distortion and power anomalies, all of which may have detrimental effects on semiconductor device operation. Line inductance reduces power surges. Inductive power circuit components such as reactors, inductors, chokes and transformers reduce rate of current change in the circuit and are used to "condition" power circuit. Inductance is often expressed in value of "percent impedance".

Definition:

Percent Impedance or Percent IZ (%IZ) is the voltage drop due to impedance, at rated current, expressed in a percent of the rated voltage.


Discussion:

Drives require certain line impedance for three important reasons:

  1. Minimum inductance is necessary for proper commutation of semiconductor devices.
  2. Line inductance reduces power sub-transient and transient surges.
  3. Impedance reduces available short circuit current in case of malfunction.



Drives Installation and Operation Manuals list necessary minimum impedance and short circuit ratings. What do these impedance percentages really mean? As stated in the above definition, percent impedance is always expressed at rated base current. It is very important to understand that recommended percent impedance is based on drive full load current rating and not the reactor, transformer, or other device current rating.

Calculating line impedance

The purpose of these examples is to illustrate the importance that percent impedance in drives application must be evaluated on drive current rating base. Lets us further examine the above examples. Let us assume that the 10HP, 460V, 14A drive above is the only load on this 100kVA transformer. How much will voltage drop on the transformer when transformer is loaded only with 14A of drive's current? In order to calculate this drop we use the simple ratio formula. If 125A drops 23V, then 14A will drop 14A/125A*23V or 2.6V. This value 2.6V is less then recommended drive input line impedance voltage drop of 4.6V. The conclusion is that 5% impedance 100kVA transformer does not meet the requirement of 1% impedance for 10HP drive.


Definition: %Z = ((VD x 100) / VS ) x √3

Z = Impedance (three phase)

VD = Voltage drop across reactor

VS = Voltage supply for rated current to flow through reactor


Evaluating short circuit impedance

Power source impedance is also and easy way to evaluate available short circuit rating. In the above example, we have discussed H2, 10HP, 460V drive which has listed short circuit rating of 5,000A symmetrical RMS (root means square) current. Let us conduct and a simple short circuit study. Let us assume that 100kVA transformer has unlimited power available from the utility on the primary side (which is mostly a case in short circuit studies) and let us assume that there are no rotating motors on this power system to contribute to short circuit level (which is not a case in most short studies). In this circuit with the assumptions made, the phase to phase of short circuit in the drive, at the simplest calculation will be full load current divided by percent impedance or 125A/.05=2500A. The available short circuit current is less then drive listed short circuit rating. There is no reason for concern. Now let us look at 200kVA, 250A, transformer with 4% impedance. Short circuit current on the drive feed from this transformer would be 6.3kA, more then drive short circuit rating. Installing this 10HP drive on 200kVA transformer possibly compromises drive short circuit rating and increases the possibility of drive failure.



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Applying AC Line Reactors



applying line reactor

Input to Inverter/Drive
AC Line Reactors protect your sensitive equipment from noise generated by the drive or inverter. They protect the controller from power surges, spikes and harmonic distortion.



applying line reactor

Output of Inverter/Drive
Motors run cooler and quieter with an AC Line Reactor placed between the inverter and motor. This application also reduces dv/dt and protects the controller from short circuits and surges.



applying line reactor

Multiple Controllers on a Single Power Line
Each drive or inverter on a single power line requires its own AC Line Reactor in order to provide adequate surge protection, prevent crosstalk and reduce harmonic distortion.



applying line reactor

Multiple Motors Controlled by a Single Drive
Multiple motors controlled by a single drive require only one AC Line Reactor between the controller and motors.




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Line Reactors Cross Brand Reference



230/240 Volts Amps % Impedance weg logo acme logo baldor logo hammond logo
  2 2.4        
3        
4        
5        
6   ALRB002TBC,
ALRB002LWE
   
10   ALRC002LWE,
ALRC002TBC
   
4 2.4        
3     LRAC00401 RM0004N30,
RM0004N65,
RM0004N30E,
RM0004N65E
4        
5       RM0004M12,
RM0004N65,
RM0004M12E,
RM0004N65E
6   ALRB004TBC,
ALRB004LWE
   
10   ALRC004LWE,
ALRC004TBC
   
8 2.4        
3     LRAC00801 RM0008N15,
RM0008N30,
RM0008N15E,
RM0008N30E
4        
5       RM0008N30,
RM0008N50,
RM0008N30E,
RM0008N50E
6   ALRB008TBC,
ALRB008LWE
   
10   ALRC008LWE,
ALRC008TBC
   
12 2.4        
3 LRW012D3N1   LRAC01201 RM0012N13,
RM0012N13E
4        
5       RM0012N25,
RM0012N25E
6   ALRB012LWE,
ALRB012TBC
   
10   ALRC012LWE    
18 2.4      
3 LRW018D3N1   LRAC01801 RM0018P80,
RM0018P80E
4        
5       RM0018N15,
RM0018N15E
6        
10        
25 2.4    
3 LRW025D3N1   LRAC02501 RM0025P50,
RM0025P50E
4        
5       RM0025N12,
RM0025N12E
6   ALRB025LWE,
ALRB025TBC
   
10   ALRC025LWE,
ALRC025TBC
   
35 2.4        
3 LRW035D3N1   LRAC03501 RM0035P40,
RM0035P40E
4        
5       RM0035P80,
RM0035P80E
6   ALRB035LWE,
ALRB035TBC
   
10   ALRC035LWE,
ALRC035TBC
   
45 2.4        
3 LRW045D3N1   LRAC04501 RM0045P30,
RM0045P30E
4        
5        
6   ALRB045LWE,
ALRB045TBC
   
10   ALRC045LWE,
ALRC045TBC
   
55 2.4        
3 LRW055D3N1   LRAC05501 RM0055P25,
RM0055P25E
4        
5       RM0055P50,
RM0055P50E
6   ALRB055LWE,
ALRB055TBC
   
10   ALRC055LWE,
ALRC055TBC
   
80 2.4      
3 LRW080D3N1     RM0080P20
4        
5       RM0080P40,
RM0080P23,
RM0080P40E,
RM0080P23E
6   ALRB080LWE,
ALRB080TBC
   
10   ALRC080LWE,
ALRC080TBC
   
100 2.4        
3 LRW100D3N1      
4        
5        
6        
10        
110 2.4        
3     LRAC110BCB  
4        
5       RM0110P18,
RM0110P18E
6   ALRB110LWE,
ALRB110CBC
   
10   ALRC110LWE,
ALRC110CBC
   
130 2.4        
3 LRW130D3N1     RM0130P10,
RM0130P10E
4        
5       RM0130P20,
RM0130P20E
6   ALRB130LWE,
ALRB130CBC
   
10   ALRC130LWE,
ALRC130CBC
   
160 2.4      
3 LRW160D3N1     RM0160U75,
RM0160U75E
4        
5       RM0160P15,
RM0160P15E
6   ALRB160LWE,
ALRB160CBC
   
10   ALRC160LWE,
ALRC160CBC
   
200 2.4      
3 LRW200D3N1     RM0200U55,
RM0200U55E
4        
5       RM0200P11,
RM0200P11E
6   ALRB200CBC    
10   ALRC200CBC    
250 2.4        
3        
4        
5       RM0250U90,
RM0250U90E
6        
10        
300 2.4      
3        
4        
5        
6        
10   ALRC300CBC    




460/480 Volts Amps % Impedance weg logo acme logo baldor logo hammond logo
  2 2.4        
3 LRW002G3N1 ALRB002TBC,
ALRB002LWE
LRAC00201,
LRAC00202
RM0002M12,
RM0002M12E
4        
5   ALRC002TBC, ALRC002LWE   RM0002M20,
RM0002M20E
6        
10        
4 2.4        
3 LRW004G3N1 ALRB004TBC,
ALRB004LWE
LRAC00402,
LRAC00403
RM0004N91,
RM0004N65,
RM0004N91E,
RM0004N65E
4        
5   ALRC004TBC,
ALRC004LWE
   
6        
10        
8 2.4        
3 LRW008G3N1 ALRB008TBC,
ALRB008LWE
LRAC00802,
LRAC00803
RM0008N30,
RM0008N50,
RM0008N30E,
RM0008N50E
4        
5   ALRC008TBC,
ALRC008LWE
  RM0008N50,
RM0008N75,
RM0008N50E,
RM0008N75E
6        
10        
12 2.4        
3 LRW012G3N1 ALRB012LWE, ALRB012TBC LRAC01202 RM0012N25,
RM0012N25E
4        
5   ALRC012LWE,
ALRC012TBC
   
6        
10        
18 2.4        
3 LRW018G3N1   LRAC01802 RM0018N15,
RM0018N15E
4        
5        
6        
10        
25 2.4        
3 LRW025G3N1 ALRB025TBC,
ALRB025LWE
LRAC02502

RM0025N12,
RM0025N12E

4        
5   ALRC025TBC,
ALRC025LWE
  RM0025N20,
RM0025N20E
6        
10        
35 2.4        
3 LRW035G3N1 ALRB035TBC,
ALRB035LWE
LRAC03502 RM0035P80,
RM0035P80E
4        
5   ALRC035TBC,
ALRC035LWE
  RM0035N17,
RM0035N12,
RM0035N17E,
RM0035N12E
6        
10        
45 2.4        
3 LRW045G3N1 ALRB045TBC,
ALRB045LWE
LRAC04502 RM0045P70,
RM0045P70E
4        
5   ALRC045TBC,
ALRC045LWE
  RM0045N12,
RM0045N12E
6        
10        
55 2.4        
3 LRW055G3N1 ALRB055TBC,
ALRB055LWE
LRAC05502 RM0055P50,
RM0055P50E
4        
5   ALRC055TBC,
ALRC055LWE
  RM0055P85,
RM0055P85E
6        
10        
80 2.4        
3 LRW080G3N1 ALRB080TBC,
ALRB080LWE
LRAC08002 RM0080P40,
RM0080P40E
4        
5   ALRC080TBC,
ALRC080LWE
  RM0080P70,
RM0080P70E
6        
10        
100 2.4        
3 LRW100G3N1      
4        
5        
6        
10        
110 2.4        
3   ALRB110CBC,
ALRB110LWE
  RM0110P30,
RM0110P30E
4        
5   ALRC110CBC,
ALRC110LWE
  RM0110P45,
RM0110P45E
6        
10        
130 2.4      
3 LRW130G3N1 ALRB130CBC, ALRB130LWE   RM0130P20,
RM0130P20E
4        
5   ALRC130CBC,
ALRC130LWE
  RM0130P30,
RM0130P30E
6        
10        
160 2.4      
3 LRW160G3N1 ALRB160CBC,
ALRB160LWE
LRAC160ACB2 RM0160P15,
RM0160P15E
4        
5   ALRC160CBC,
ALRC160LWE
  RM0160P23,
RM0160P23E
6        
10        
200 2.4  
   
3 LRW200G3N1 ALRB200CBC   RM0200P11,
RM0200P11E
4        
5   ALRC200CBC    
6        
10        
250 2.4  
   
3 LRW250G3N1 ALRB250CBC,   RM0250U90,
RM0250U90E
4        
5   ALRC250CBC   RM0250P15,
RM0250P15E
6        
10        
300 2.4        
3        
4        
5   ALRC300CBC    
6        
10        
320 2.4        
3 LRW320G3N1      
4        
5        
6        
10        
400 2.4        
3 LRW400G3N1      
4        
5        
6        
10        
500 2.4        
3 LRW500G3N1      
4        
5        
6        
10        
600 2.4  
   
3 LRW600G3N1 ALRB600CBC   RM0600U40,
RM0600U40E
4        
5   ALRC600CBC   RM0600U65,
RM0600U65E
6        
10        
1000 2.4        
3 LRW1000G3N1      
4        
5        
6        
10      




575/600 Volts Amps % Impedance weg logo acme logo baldor logo hammond logo
  2 2.4   ALRB002LWE,
ALRB002TBC
 
3     LRAC00202 RM0002M12,
RM0002M12E
4   ALRC002LWE,
ALRC002TBC
   
5       RM0002M20,
RM0002M32,
RM0002M20E,
RM0002M32E
6        
10        
4 2.4   ALRB004LWE,
ALRB004TBC
 
3       RM0004M12,
RM0004N91,
RM0004M12E,
RM0004N91E
4   ALRC004LWE,
ALRB004TBC
   
5       RM0004M12,
RM0004M22,
RM0004M12E,
RM0004M22E
6        
10        
8 2.4   ALRB008LWE,
ALRB008TBC


3     LRAC00803 RM0008N50,
RM0008N50E
4   ALRC008LWE,
ALRC008TBC
   
5       RM0008N75,
RM0008N75E
6        
10        
12 2.4   ALRB012LWE,
ALRB012TBC
 
3     LRAC01202 RM0012N25,
RM0012N31,
RM0012N25E,
RM0012N31E
4   ALRC012LWE,
ALRC012TBC
   
5       RM0012N42,
RM0012N51,
RM0012N42E,
RM0012N51E
6        
10        
18 2.4        
3     LRAC01802 RM0018N15,
RM0018N15E
4        
5       RM0018N25,
RM0018N25E
6        
10        
25 2.4   ALRB025LWE,
ALRB025TBC
   
3     LRAC02502 RM0025N12,
RM0025N12E
4   ALRC025LWE,
ALRC025TBC
   
5       RM0025N20,
RM0025N20E
6        
10        
35 2.4   ALRB035LWE,
ALRB035TBC
   
3     LRAC03502 RM0035P80,
RM0035P80E
4   ALRC035LWE,
ALRC035TBC
   
5       RM0035N17,
RM0035N17E
6        
10        
45 2.4   ALRB045LWE,
ALRB045TBC
   
3     LRAC04502 RM0045P70,
RM0045P70E
4   ALRC045LWE,
ALRC045TBC
   
5       RM0045N12,
RM0045N12E
6        
10        
55 2.4   ALRB055LWE,
ALRB055TBC
   
3       RM0055P50,
RM0055P50E
4   ALRC055LWE,
ALRC055TBC
   
5        
6        
10        
80 2.4   ALRB080LWE,
ALRB080TBC
   
3     LRAC08002 RM0080P40,
RM0080P40E
4   ALRC080LWE,
ALRC080TBC
   
5       RM0080P70,
RM0080P70E
6        
10        
110 2.4   ALRB110LWE,
ALRB110CBC
   
3       RM0110P30,
RM0110P30E
4   ALRC110LWE,
ALRC110CBC
   
5       RM0110P45,
RM0110P45E
6        
10        
130 2.4   ALRB130LWE,
ALRB130CBC
   
3       RM0130P20,
RM0130P20E
4   ALRC130LWE,
ALRC130CBC
   
5       RM0130P37,
RM0130P37E
6        
10        
160 2.4   ALRB160LWE,
ALRB160CBC
   
3       RM0160P23,
RM0160P23E
4   ALRC160LWE,
ALRC160CBC
   
5       RM0160P32,
RM0160P32E
6        
10        
250 2.4        
3       RM0250P15,
RM0250P15E
4        
5        
6        
10