Line Reactors; Load Reactors; Line Disconnect; Protective Devices - Baldor VS1GV21-1B Installation & Operating Manual

4.2.1 Line Reactors

Three phase line reactors are available from Baldor. The line reactor to order is based on the full load current of the motor
(FLA). If providing your own line reactor, use the following formula to calculate the minimum inductance required.

4.2.2 Load Reactors

Line reactors may be used at the drive output to the motor. When used this way, they are called Load Reactors. Load
reactors serve several functions that include:
• Protect the drive from a short circuit at the motor.
• Limit the rate of rise of motor surge currents.
• Slowing the rate of change of power the drive delivers to the motor.
Load reactors should be installed as close to the drive as possible. Selection should be based on the motor nameplate FLA
value.

4.3 Line Disconnect

A power disconnect should be installed between the input power service and the drive for a fail safe method to disconnect
power. This drive will remain in a powered-up condition until all input power is removed from the drive and the internal bus
voltage is depleted.

4.4 Protective Devices

NOTE: Integral solid state short circuit protection does not provide branch circuit protection. Branch circuit protection must
be provided in accordance with the National Electrical Code and any additional local codes.
Recommended fuse sizes are based on the following:
115% of maximum continuous drive input current for time delay.
150% of maximum continuous drive input current for Fast or Very Fast action.
Note: These recommendations do not consider harmonic currents or ambient temperatures greater than 45°C. Be sure a
suitable input power protection device is installed. Use the recommended fuses and wire sizes shown in Tables
4-1 through 4-6. Wire size is based on the use of copper conductor wire rated at 75°C. The table is specified for
NEMA B motors.
Fast Action Fuses:
Very Fast Action:
Time Delay:
Semiconductor
Fuses:
UL Listed Breakers:
Buss® is a trademark of Cooper Industries, Inc.
4-2 Power Wiring
(V
L- L
L =
(I
X
Where:
L Minimum inductance in Henries.
V Input volts measured line to line.
L- L
0.01 Desired percentage of input impedance 1%.
I Input current rating of drive.
377 Constant used with 60 Hz power.
Use 314 if input power is 50 Hz.
240VAC, Buss® KTN
480VAC, Buss® KTS to 600A (KTU for 601 to 1200A)
600VAC, Buss® KTS to 600A (KTU for 601 to 1200A)
240VAC, Buss® JJN
480VAC, Buss® JJS
600VAC, Buss® JJS
240VAC, BUSS FRN
480VAC, BUSS FRS (KLU for 601 to 1200A)
600VAC, BUSS FRS (KLU for 601 to 1200A)
240VAC, Ferraz Shawmut A50QS
480VAC, Ferraz Shawmut A70QS
600VAC, Ferraz Shawmut A70QS
Frame Size D - 250 A maximum (all ratings)
Frame Size E - 300 A maximum for the 150 HP
400 A maximum for the 200 HP
500A maximum for the 250 HP
Frame Size F - 600A maximum for the 300 HP
700A maximum for the 350 HP
750A maximum for the 400 HP
800A maximum for the 450 HP
1000A maximum for the 500 HP
0.01)
X
3 377)
X
(Note: Change this value to
0.03 for AA Frame size drives
and for B Frame size NEMA 4X
drives.)
MN765