User Manual Owner's manual

264 Rockwell Automation Publication 280E-UM001B-EN-P - July 2012
Appendix A Applying More Than One ArmorStart Motor Controller in a Single Branch Circuit on Industrial Machinery
according to NFPA 79 or NFPA 70 (or both). The definition of industrial
machinery is found in 3.3.56 of NFPA 79 and 670.2 of Article 670, Industrial
Machinery, in NFPA 70.
These conventions are used throughout this appendix. First, although all of the
equipment is connected to a three-phase electrical supply, all of the figures are
shown as one-line diagrams. Second, although all of the ArmorStart LT motor
controllers are listed for group installation with both fuses and a specific family of
inverse time circuit breakers, this appendix considers only fuses. This is done to
avoid repetitive explanations with minor, but necessary qualifications, for circuit
breakers. Generally, the principles for selecting the fuses also apply to selecting
inverse time circuit breakers. Third, all references, unless indicated otherwise, are
to NFPA 79 – 2012.
Note: The following example uses ArmorStart LT. This provides a more
comprehensive example,
Figure 95 - ArmorStart LT NFPA 79 Multi-Motor Branch Circuit
ArmorStart LT Product Family
This section contains a brief description of the attributes of the ArmorStart LT
motor controllers that are relevant to applying them in multiple-motor branch
circuits.
The term motor controller refers to the device that stops and starts the motor.
The ArmorStart LT product family consists of two types of motor controllers.
The Bulletin 290 and 291 controllers are magnetic motor controllers that use an
electromechanical contactor to stop and start the motor. The Bulletin 294 motor
Electrical Supply
Disconnecting
Means
Single Set of Fuses
Final
Overcurrent
Device
NFPA 79, 3.3.10 Branch Circuit. The Circuit
Conductors Between the Final Overcurrent Device
Protecting the Circuit and the Outlet(s). [70:100]
Any Mixture of Motor Controller
Technologies
* Each Controller is Listed for Group
Installation with Specied Maximum
Protection
Two or More Motors with any
Mixture or Power Ratings
½ HP
Bulletin 294
2 HP
Bulletin 294
5 HP
Bulletin 291
5 HP
Bulletin 290
1 HP
Bulletin 294
Overload
Class 10
Overload
Class 10
Overload
Class 10/15/20
Overload
Class 10/15/20
Overload
Class 10
Nameplate* Nameplate* Nameplate* Nameplate* Nameplate*
1/2 Hp 2 Hp 5 Hp 5 Hp 1 Hp