Shopsmith Forums

Bill, what's the continuous current rating on the Emerson motors? I think I know the answer to this, but does the motor or the SS headstock have any internal overcurrent protection or thermal cutouts?

BuckeyeDennis wrote:Bill, what's the continuous current rating on the Emerson motors? I think I know the answer to this, but does the motor or the SS headstock have any internal overcurrent protection or thermal cutouts?

None of the SS motors have any.

Bill Mayo's analysis is fascinating! I know in my early days with my 510, I had whacked the table out of alignment, and I was "growling" that motor on some tablesaw cuts.
These days, though, with the table aligned nicely and the whopper PowerPro, it's grease city .

Chris

JPG wrote:

BuckeyeDennis wrote:Bill, what's the continuous current rating on the Emerson motors? I think I know the answer to this, but does the motor or the SS headstock have any internal overcurrent protection or thermal cutouts?

None of the SS motors have any.

SS must have decided to rely on the branch-circuit protection. The NEC gives the full-load amperage for a 1 hp 115 V motor as 16A. So from Bill's information, my hunch is that the SS motors are adequately protected on a 15A circuit. But perhaps at risk on a 20A circuit.

BuckeyeDennis wrote:

JPG wrote:

BuckeyeDennis wrote:Bill, what's the continuous current rating on the Emerson motors? I think I know the answer to this, but does the motor or the SS headstock have any internal overcurrent protection or thermal cutouts?

None of the SS motors have any.

SS must have decided to rely on the branch-circuit protection. The NEC gives the full-load amperage for a 1 hp 115 V motor as 16A. So from Bill's information, my hunch is that the SS motors are adequately protected on a 15A circuit. But perhaps at risk on a 20A circuit.

A 'detail' usually not considered when trying to get the most from the motor(20A #12 wiring etc.).

Now the motor will tell you when it is at risk. It hums loudly!

BuckeyeDennis wrote:

JPG wrote:

BuckeyeDennis wrote:Bill, what's the continuous current rating on the Emerson motors? I think I know the answer to this, but does the motor or the SS headstock have any internal overcurrent protection or thermal cutouts?

None of the SS motors have any.

SS must have decided to rely on the branch-circuit protection. The NEC gives the full-load amperage for a 1 hp 115 V motor as 16A. So from Bill's information, my hunch is that the SS motors are adequately protected on a 15A circuit. But perhaps at risk on a 20A circuit.

Please correct me if I am wrong but I always thought a circuit breaker was there to protect the wiring leading up to it not the item attached to the circuit.

No 'correction' needed.

jsburger wrote:

BuckeyeDennis wrote: SS must have decided to rely on the branch-circuit protection. The NEC gives the full-load amperage for a 1 hp 115 V motor as 16A. So from Bill's information, my hunch is that the SS motors are adequately protected on a 15A circuit. But perhaps at risk on a 20A circuit.

Please correct me if I am wrong but I always thought a circuit breaker was there to protect the wiring leading up to it not the item attached to the circuit.

In general that's true. But doubting that Shopsmith products violate code, I just checked NFPA 70 (the National Electric Code). Here's what I found:

BuckeyeDennis wrote:

jsburger wrote:

BuckeyeDennis wrote: SS must have decided to rely on the branch-circuit protection. The NEC gives the full-load amperage for a 1 hp 115 V motor as 16A. So from Bill's information, my hunch is that the SS motors are adequately protected on a 15A circuit. But perhaps at risk on a 20A circuit.

Please correct me if I am wrong but I always thought a circuit breaker was there to protect the wiring leading up to it not the item attached to the circuit.

In general that's true. But doubting that Shopsmith products violate code, I just checked NFPA 70 (the National Electric Code). Here's what I found:

430.33.PNG

430.52.PNG

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.

John said "SS equipment was designed for residential circuits".

I think that I know what point he is trying to make but quite frankly the Shopsmith was designed long enough ago that I doubt the same building codes are in existence today. Suffice it to say that the Shopsmith motors are designed such that they can be used on a standard residential 15 amp circuit.

I know that many believe that a 20amp circuit is more appropriate. I don't. I have had my Shopsmith on a 15amp circuit for what seems like forever. Now I can't run anything on that same circuit at the same time but the 15amp breaker hardly ever trips. I can't tell you how long it has been since the last time.

I knew, when our house was being built, that I was going to have a shop in the garage. I ask for outlets on three separate circuits to be installed in the garage. That got done BUT two of them are not dedicated to the shop. My error for not being more specific. But it all works. I have just disciplined myself as to which outlets can be used without creating chaos.