Protective Devices; Reduced Input Voltage Considerations; Electrical Installation; Motor Overtemperature Sensing - Baldor VS1SD Installation & Operating Manual

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 specifi ed 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.

4.5 Reduced Input Voltage Considerations

Power ratings are for nominal AC input voltages (240 or 480VAC). The power rating of the drive must be reduced when
operating at a reduced input voltage. The amount of reduction is the ratio of the voltage change.
Examples:
A 5HP, 240VAC drive operating at 208VAC has an effective power rating of 4.33HP.
208VAC
5Hp x
240VAC
Likewise, a 3HP, 480VAC drive operating at 380VAC has an effective power rating of 2.37HP.
380VAC
3Hp x
480VAC

4.6 Electrical Installation

All interconnection wires between the drive, AC power source, motor, host control and any other operator interface stations
should be in metal conduits or shielded cable must be used. If the connection being made is on a connection stud or
grounding screw, then use listed closed loop connectors that are of appropriate size for wire gauge being used. Connectors
are to be installed using crimp tool specifi ed by the manufacturer of the connector. Only Class 1 wiring should be used. See
Figure A-2 in Appendix A for conduit hole size for each frame size.

4.7 Motor Overtemperature Sensing

All VS1SD must be used with Motor Overtemperature Sensing. The Motor Overtemperature Sensing equipment must disable
the drive in the event of an overtemperature condition. This can be accomplished via the use of the TH1 and TH2 terminals.
See Figure 1-1 for proper connection.
MN766
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 (22.8mm) M20, PG16
600VAC, Ferraz Shawmut A70QS
Frame Size D - 250A maximum (all ratings)
= 4.33Hp
= 2.37Hp
Power Wiring 4-3