IS starter circuit

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pillage

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I have a classic momentary start/stop pushbutton station in a C1D1 location. The NC start contact, starter auxiliary hold-in contact, and the NO stop contact are wired through IS barriers back to the motor motor starter with 24VDC coil.

There is a concern here that the proximity of the starter auxiliary to the starter cannot be used in an IS circuit because of the proximity to the non-isolated wiring of the starter, even though it is isolated through an IS barrier.

Is this concern legit???

Thanks in advance for your input.
 
charlie b

charlie b

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I understood all of the acronyms except "IS." Not that I could answer this question anyway (outside my area), but what does "IS" stand for?

Welcome to the forum.
 
rbalex

rbalex

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The concern is valid. Simply adding an IS barrier to a circuit does not necessarily make an installation IS; in fact, it usually doesn?t.

The most commonly overlooked requirement for IS installations is Section 504.10(A). Do you have the ?Control Drawing?? See the definition in Section 500.2.

In addition, the entire Section 504.30 should be reviewed, especially Subsection 504.30(A)(2) with respect to the OP.
 
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