Mike Dolt Enterprises
Mike Dolt Enterprises
User: DTan, Location: Northern Minnesota
Asked on: Thursday, March 17, 2011 at 2:53 pm EDT
Answered on: Tuesday, May 14, 2024 at 2:56 am EDT
Question: We have a roughly 300? long auger for moving wood shavings that runs from one building into another. It starts inside the first building on the second floor, exits the building to run over the roof of the second building (no second floor) and ends up in a small shed on top of the second building to keep the unloading end out of the weather. Each end of it has a 10HP motor driving it, and there is a slip fitting about half way down the length of it it so that the 2 halves of the auger shaft aren?t directly connected together. Both ends need to run at the same time for it to operate correctly. Shavings get dumped into the auger at multiple locations along the length of it from various systems.Is there a way to legally power the motor in building A from a control panel in building B? I?m trying to avoid dealing putting a remote starter in building B powered from that building and running all the safety interlocking between the 2 buildings of them. It?s a situation where we need to have monitoring safety relays, multiple pull cable stops, etc. so it would be a lot simpler to bring all the field devices into 1 control panel that has the starters, PLC, etc and just run power out to the motor in the other building. The wiring will be a lot more complicated (and future troubleshooting much more difficult) if we have to run interlocks and other control wiring back and forth between the ends of the conveyor.
Yes, it is legally possible to power the motor in building A from a control panel in building B, provided that certain requirements are met.
Requirements
NEC Article 430.22
The motor feeder must be rated for the full load current of the motor.
NEC Article 430.102(B)(2)
The motor feeder must be protected against overcurrent by a circuit breaker or fuse located at the power source.
NEC Article 705.12
The motor controller must be located within sight of the motor, or remote operation must be provided with devices that will protect the motor from damage.
NEC Article 430.122(A)
The motor controller must be suitable for the type of motor being used.*
NEC Article 430.114
The motor controller must be installed in accordance with the manufacturer's instructions.
Recommended Approach
1.
Run a Motor Feeder
Install a dedicated motor feeder from the control panel in building B to the motor in building A. The feeder must be sized for the motor's full load current and protected by a circuit breaker or fuse at the panel.2.
Install a Motor Controller
Install a motor controller in the control panel in building B that meets the requirements of NEC Article 430.122(A).
3.
Connect the Motor
Connect the motor in building A to the motor controller in building B according to the manufacturer's instructions.4.
Provide Sight or Remote Protection
Ensure that the motor controller in building B can be operated within sight of the motor in building A. If remote operation is necessary, install devices that will protect the motor from damage, such as interlocking safety relays and pull cable stops.
Note: It is important to consult with a qualified electrician to ensure that the installation complies with all applicable electrical codes and safety regulations. Flag for review