Generator prime mover shutdown

[SceneryDriver]

In the 2017 NEC, 445.18 (B) states that a prime mover for a generator greater than 15KW needs a shutdown provision "external to the equipment room or generator enclosure..."

Does this requirement extend to a 20KW natural gas-fired standby generator for a residence? I'm being asked if a shutdown provision is needed for a generator I recently installed. I can probably provide one, but there's no factory provision for the connection, and it will probably void the Millbank warranty if I go splicing into the genny's control wiring to install an E-stop pushbutton.

For reference, I can yank the 20A 12V fuse that's part of the control circuit, and that will prevent the genny from starting, but that's "inside the generator enclosure," so I'm not sure it qualifies as a shutdown means.

Thoughts?


Thanks,

SceneryDriver

 

[petersonra]

(B) Shutdown of Prime Mover. Generators shall have provisions
to shut down the prime mover. The means of shutdown
shall comply with all of the following:
(1) Be equipped with provisions to disable all prime mover
start control circuits to render the prime mover incapable
of starting
(2) Initiate a shutdown mechanism that requires a mechanical
reset

How does pulling the fuse satisfy (B)(2)?

 

[GoldDigger]

How does pulling the fuse satisfy (B)(2)?

I think that replacing the fuse qualifies as a manual reset operation.
It does not have to be a button or lever marked "reset". It just requires that the generator not be able to restart automatically or be restarted manually by the normal push button or activating signal until some manual action is taken which is not part of the routine start sequence.
If the normal operating procedure is to pull the fuse to stop and re-insert the fuse to start, then I would agree that it would not qualify as a manual reset. :happyyes:

 

[SceneryDriver]

How does pulling the fuse satisfy (B)(2)?

That's what I was thinking. That said, it was installed under the '14 NEC. My '14 copy grew legs and wandered away recently, so I can't check to see if (2)(B) was a requirement in the previous cycle.

How would you approach this, what with the possibility of warranty issues stemming from tying into the control circuit in a non-factory-approved manner? It's easy electrically, just not necessarily wise. Does this even apply to a residential genny?


Thanks,

SceneryDriver

 

[don_resqcapt19]

That's what I was thinking. That said, it was installed under the '14 NEC. My '14 copy grew legs and wandered away recently, so I can't check to see if (2)(B) was a requirement in the previous cycle. ...
Thanks,

SceneryDriver

Sure you can The grey highlighted "N" in front of the section tells you that it was new for the 2017 code. Here is the text from the 14 code.

445.18 Disconnecting Means Required for Generators
Generators shall be equipped with a disconnect(s), lockable in the open position by means of which the generator and all protective devices and control apparatus are able to be disconnected entirely from the circuits supplied by the generator except where the following conditions apply:
(1) Portable generators are cord- and plug-connected, or
(2) Both of the following conditions apply:
a. The driving means for the generator can be readily shut down, is rendered incapable of restarting, and is lockable in the OFF position in accordance with 110.25.
b. The generator is not arranged to operate in parallel with another generator or other source of voltage.

Informational Note: See UL 2200-2012, Standard for Safety of Stationary Engine Generator Assemblies.

 

[SceneryDriver]

Sure you can The grey highlighted "N" in front of the section tells you that it was new for the 2017 code. Here is the text from the 14 code.

I knew the text was new, I just didn't know what it said last code cycle.

Went back and looked at the site; the gas valve the plumber installed is readily accessible, and is a padlockable ball valve. If it's shut off and locked, that should satisfy:

"...rendered incapable of restarting, and is lockable in the OFF position."

The generator breaker in the ATS is also LOTO lockable in the OFF position, so that's helpful as well.



SceneryDriver

 

[qcroanoke]

I knew the text was new, I just didn't know what it said last code cycle.

Went back and looked at the site; the gas valve the plumber installed is readily accessible, and is a padlockable ball valve. If it's shut off and locked, that should satisfy:

"...rendered incapable of restarting, and is lockable in the OFF position."

The generator breaker in the ATS is also LOTO lockable in the OFF position, so that's helpful as well.



SceneryDriver

But it can still crank.
I think you have to get in the start circuit or the EPO and open it to comply. JMO