No backlog on PowerPro

hdtran · Post by **hdtran** » Wed Apr 27, 2011 7:36 pm

I had an income tax overpayment that came back, sufficient to fund a refurbished PowerPro.

No backlog. Called in an order, & it shipped that same day (!).

Got it set up (without help, but with some serious grunting) in about 1.5 hrs (mostly, rigging some spacers to minimize risk of injury with maneuvering heavy headstocks).

Tripped the GFCI with the following combinations:
(1) Powerpro plugged into a 50 ft heavy duty extension cord; extension plugged into GFCI outlet
(2) Plugged directly into GFCI outlet
(3) Plugged into a powerstrip (claims to be surge protector); powerstrip plugged into GFCI outlet
(4) Plugged into extension cord plugged into surge protector, into outlet.

Finally, I gave up and plugged the extension cord into a different outlet in the garage (which I'm sure is wired to the GFCI, because it's near the hot water heater, but does not have the GFCI buttons). That worked fine.

Tested my bandsaw, no rattles. I do have a bent spot in my bandsaw blade, so the bandsaw is noisy. Lathe is great.

I'll arrange to ship the old headstock back later.

charlese · Post by **charlese** » Wed Apr 27, 2011 7:49 pm

Great news! Congratulations! Have a good time with it. It is a wonderfull tool!!!!!

8iowa · Post by **8iowa** » Thu Apr 28, 2011 8:41 am

The electrial code calls for GFI's in garages and basements. Perhaps the best way to get around this problem is to put in a 240V recepticle and run the Power Pro on 240. That's what I did in Gainesville. My "Workshop in the Woods" is already set up for 240V. A 15 amp 240V plug& recepticle is adequate. This also increases the Power Pro's rating to 2 HP.

robinson46176 · Post by **robinson46176** » Thu Apr 28, 2011 10:08 am

I have to wonder if "no backlog" is a good thing because of rapid production or a bad thing due to lagging sales?

.

wa2crk · Post by **wa2crk** » Thu Apr 28, 2011 1:03 pm

Curioser and curioser.
I have run my Power Pro under the same conditions as described in the first post without any problems. Sure would like to know what is causing the difficultied with SOME GFCI circuits.
I have also plugged my PP into a power strip which has MOV surge protectors and then into the GFCI outlet without any issues.
Bill V

BigSky · Post by **BigSky** » Thu Apr 28, 2011 1:54 pm

robinson46176 wrote:I have to wonder if "no backlog" is a good thing because of rapid production or a bad thing due to lagging sales?
.

I thought that Shopsmith had been having financial problems and that some vendors would not provide parts on credit. If that is true, it would likely have created some back log.

Hopefully, no back log is an indication that those days are gone. That is what I would hope for. The road to recovery is now clear.

justplaingoofy · Post by **justplaingoofy** » Thu Apr 28, 2011 2:49 pm

hdtran,

Look at the outside of that extension cord you were using and post the jargon you'll find on the outer sheathing.

You said the gfi blew. Did it blow INSTANTLY when you turned the SS on, or did it take a while?

Also, where is your gfi? at the outlet you plugged the extension cord into?...or at the panel, and you have a gfi 'breaker' there for an entire circuit?

Regarding the outlet that blew: Is it a 15 or 20 amp circuit?
Is there anything else plugged in and "ON" in that same circuit? Even light bulbs! You need to know everything that works off that circuit.

I suspect your problem is not the gfi. It's more likely inadequate wiring for the amp draw you have, especially that extension cord, or, you simply overloaded an already partially loaded up circuit.

Example: Say you have a 15amp circuit that has your computer on it, lights, maybe even the fridge. Just for illustration, say all that draws 11.8 amps. All is good. Then, plug in the SS, which draws 9.8amps at 110V and bingo, overloaded circuit.

hdtran · Post by **hdtran** » Thu Apr 28, 2011 7:01 pm

justplaingoofy wrote:hdtran,

Look at the outside of that extension cord you were using and post the jargon you'll find on the outer sheathing.

You said the gfi blew. Did it blow INSTANTLY when you turned the SS on, or did it take a while?

Also, where is your gfi? at the outlet you plugged the extension cord into?...or at the panel, and you have a gfi 'breaker' there for an entire circuit?

Regarding the outlet that blew: Is it a 15 or 20 amp circuit?
Is there anything else plugged in and "ON" in that same circuit? Even light bulbs! You need to know everything that works off that circuit.

I suspect your problem is not the gfi. It's more likely inadequate wiring for the amp draw you have, especially that extension cord, or, you simply overloaded an already partially loaded up circuit.

Example: Say you have a 15amp circuit that has your computer on it, lights, maybe even the fridge. Just for illustration, say all that draws 11.8 amps. All is good. Then, plug in the SS, which draws 9.8amps at 110V and bingo, overloaded circuit.

The circuit has a fridge further downstream of the GFI outlet, but it runs the fridge, a 1HP dust collector, and the non-PP headstock without issues.

The extension cord that I use is an industrial style cord. I don't remember the exact rating, but it's more than adequate.

When the GFI blows, it doesn't do so instantly. When I power up the PP, it beeps, then, the LCD display lights up, and it begins some sort of self-test power up sequence. Several seconds into that sequence, the GFI trips. The LCD takes a few seconds before dimming.

Without opening up the headstock and looking at the innards, I speculate:

(1) The electronics are driven by a universal switching supply with some fairly hefty capacitors. Sometime during power up and self-test, the PP headstock puts some harmonics on the line. The GFI (which came stock with the house, so I'm assuming the contractor chose an inexpensive brand), probably sensed the harmonics as a ground current, and tripped.

(2) When operating at a circuit protected by the GFI, but further downstream, the added inductance of the wiring run kills the harmonics.

(3) The extension cord doesn't have enough inductance to kill the harmonics.

(4) My so-called surge protector is really just a power strip without a choke or MOV's.

I'm running the PP from an outlet about 10 ft away from the original GFI outlet, but this outlet is also wired to the GFI (if GFI blows, so will this outlet).

I am not a licensed electrician, nor am I familiar with NEC (nor do I want to be familiar with NEC!); but I am registered as a PE in electrical engineering, and I think my hypotheses stated above are as good as anyone else's

JPG · Post by **JPG** » Thu Apr 28, 2011 9:50 pm

[quote="hdtran"]The circuit has a fridge further downstream of the GFI outlet, but it runs the fridge, a 1HP dust collector, and the non-PP headstock without issues.

The extension cord that I use is an industrial style cord. I don't remember the exact rating, but it's more than adequate.

When the GFI blows, it doesn't do so instantly. When I power up the PP, it beeps, then, the LCD display lights up, and it begins some sort of self-test power up sequence. Several seconds into that sequence, the GFI trips. The LCD takes a few seconds before dimming.

Without opening up the headstock and looking at the innards, I speculate:

(1) The electronics are driven by a universal switching supply with some fairly hefty capacitors. Sometime during power up and self-test, the PP headstock puts some harmonics on the line. The GFI (which came stock with the house, so I'm assuming the contractor chose an inexpensive brand), probably sensed the harmonics as a ground current, and tripped.

(2) When operating at a circuit protected by the GFI, but further downstream, the added inductance of the wiring run kills the harmonics.

(3) The extension cord doesn't have enough inductance to kill the harmonics.

(4) My so-called surge protector is really just a power strip without a choke or MOV's.

I'm running the PP from an outlet about 10 ft away from the original GFI outlet, but this outlet is also wired to the GFI (if GFI blows, so will this outlet).

I am not a licensed electrician, nor am I familiar with NEC (nor do I want to be familiar with NEC!)]

Interesting!

charlese · Post by **charlese** » Fri Apr 29, 2011 1:42 am

[quote="hdtran"]Tripped the GFCI with the following combinations:
(1) Powerpro plugged into a 50 ft heavy duty extension cord]

Sounds like you solved you power problem - but thought I'd add --the same thing occurred in my shop only on GFCI outlets or down line from those outlets. It runs fine with a line attached to a GFCI circuit breaker. When talking with Wes (from Shopsmith) he told me they hadn't discovered that problem because all of their outlets are GFCI breakers mounted in the circuit box. Since then I suppose he has had a number of reports of faults with GFCI outlets.