jfosterjrod58

HOA hand switch leg direct to motor starter

Discussion created by jfosterjrod58 on Feb 19, 2019
Latest reply on Feb 26, 2019 by jfosterjrod58

   There has been some debate among my coworkers lately about the "Hand" switch leg of a rotary HOA selector switch going directly to the coil of a motor starter. I have been making the case that this is essentially illegal; with only a few, very specific instances that it is allowed. I must admit that, for years, I have done it that way hundreds of times. I know that most electricians do this as well. But since becoming a control systems technician III it has become apparent to me that this is largely not legal. 

    My reasoning is based on several codes scattered through out the NFPA 79: function definitions, as well as functions that are not permitted to initiate a start of the machinery, etc In addition, the NEC has 1 informational note that is the only single reference to any controls function that supports my argument. It is the note that addresses the resetting of the O-load (yes, I know it allows it for auto-reset if no hazards would be introduced by it). 

   In my experience too, a facility electrician, especially an outside contractor, would have no expectation of starting a machine when trouble shooting by resetting the O-load, a CB, E-stop, etc. This could easily cause additional hazards when all personnel are not expecting a start.

   I am looking for other NFPA codes that address the hazards of unexpected start-up. Perhaps NFPA 101 has some guidelines as to operators of machinery and safe start-up procedures? Or federal utility requirements in the event of a power outage and restoration? If there are no hazards from an unexpected start-up, what is required to make that assessment and document?

Thanks in advance for any info...

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