Shopsmith Forums

jsburger wrote: First of all SS products do not violate code.

I think sometimes people take things out of context and pick and choose without reading the entire spec. I am not accusing you of that.

However, table 430.52 you quote specifically says it is for Motor Branch-Circuits with protective devices with parameters as described.

Are your residential branch circuits Motor Branch-Circuits under the spec. I doubt it. SS equipment was designed for residential circuits.

Well, the NEC is certainly a complex document, and I'm no expert on it. Sometimes I'll be researching something, and find a forum where the inspectors themselves have had spirited debates on how to interpret it. But I'll attempt to explain my interpretation on this issue.

If Article 430 makes any distinction between residential and commercial installations, I couldn't find it. And I believe that the term "motor branch circuit" simply means a branch circuit to which motors are connected. But I just searched a PDF copy of the entire NEC for that term, and although there were many hits, there was no definition of the term.

Earlier, I left out the introduction of the section in question, which follows:
Section 430.32 specifies the overload-protection requirements for continuous-duty motors. This section takes up a couple of pages, but basically says that all continuous-duty motors must have dedicated overload protection devices.

And so I interpreted 430.33 as granting an exception for intermittent-duty motors, by not requiring them to have dedicated overload protection devices. As long as the branch-circuit protection device was not too large, as determined Table 430.52.

Maybe a real code expert will weigh in on this.

BuckeyeDennis wrote:

jsburger wrote: First of all SS products do not violate code.

I think sometimes people take things out of context and pick and choose without reading the entire spec. I am not accusing you of that.

However, table 430.52 you quote specifically says it is for Motor Branch-Circuits with protective devices with parameters as described.

Are your residential branch circuits Motor Branch-Circuits under the spec. I doubt it. SS equipment was designed for residential circuits.

Well, the NEC is certainly a complex document, and I'm no expert on it. Sometimes I'll be researching something, and find a forum where the inspectors themselves have had spirited debates on how to interpret it. But I'll attempt to explain my interpretation on this issue.

If Article 430 makes any distinction between residential and commercial installations, I couldn't find it. And I believe that the term "motor branch circuit" simply means a branch circuit to which motors are connected. But I just searched a PDF copy of the entire NEC for that term, and although there were many hits, there was no definition of the term.

Earlier, I left out the introduction of the section in question, which follows:

430.31.PNG

Section 430.32 specifies the overload-protection requirements for continuous-duty motors. This section takes up a couple of pages, but basically says that all continuous-duty motors must have dedicated overload protection devices.

And so I interpreted 430.33 as granting an exception for intermittent-duty motors, by not requiring them to have dedicated overload protection devices. As long as the branch-circuit protection device was not too large, as determined Table 430.52.

Maybe a real code expert will weigh in on this.

From the little bit that I have read, I concur.