SawStop Pro Electrical Issues - Tripping

[Ron Selzer]

voltage and amp readings UNDER LOAD would definitely point to where the problem is
Ron

[Bill George]

If the saw was operating perfectly for five years and nothing has changed, it can’t be the wiring and must be the saw motor.

This is what he posted above "'I've had a SawStop Pro 1.75hp 220v saw for approx. 5 years now. From day one it tripped frequently "

Yes dedicated 120 volt 20 amp plugs are different than standard.

[Paul F Franklin]

If the saw was operating perfectly for five years and nothing has changed, it can’t be the wiring and must be the saw motor.

Tom, the way I read the op, the saw has not operated correctly since first purchase....

[Frank Pratt]

There's been lots of good suggestions & questions raised. We need more feedback from the OP to be of further help. If not done already, voltage & current readings need to be done at the saw while under load.

[Malcolm McLeod]

I've had a SawStop Pro 1.75hp 220v saw for approx. 5 years now. From day one it tripped frequently ...

Has the saw ever operated 'normally' in your view? (...no trips for an hour, a day, a week?)

If as suggested, you can't get an ammeter on it, will it run for 10-15 minutes unloaded?

In addition to who performed the 120>>240V conversion, when was the conversion done? ...Day 1? (Looking for info about 'normal' operation before the conversion.)

Mr. Morse may be onto something wrong in the motor wiring. ...IMHO.

[Scott Bernstein]

I have a SawStop "1.75" PCS which I've used for about 5 years. When I purchased it, it came wired for 110V and used it that way for three years. It was on a dedicated 20Amp circuit and even then it did have trouble with really, really hard and thick wood (like 12/4 Hickory). Even with very slow feeding and a ripping blade it would trip the internal overload protection or the breaker. The motor would bog down sometimes on hard 6/4 or 8/4 material but usually with 4/4 material it was always OK. Eventually I did the upgrade to the bigger 3HP motor and 220V conversion myself and now it never bogs down on anything, no does it trip the breaker.

I agree with the questions here - is the OPs saw really wired for 220?

[Frank Pratt]

As long as everything is wired correctly to code, there is no advantage to running a saw on 120V or 240V. The question is whether the saw was correctly converted to 240V. The 120V electronics would likely evaporate in short order if connected to 240V, so that isn't the issue. If they were changed out for the 240V items, but the motor connection were not properly converted, then that could be the cause of all the tripping & lack of power.

My FIL gave me has Rockwell/Beaver table saw because it was so underpowered. It turned out to be wired for 240V, but had a 120V plug on the cord. The symptoms the OP relates are exactly what that saw of mine acted like. Once I rewired the motor, it ran like it should. Otherwise, the saw was a real POS & I eventually unloaded it for $50.

[Bert McMahan]

As long as everything is wired correctly to code, there is no advantage to running a saw on 120V or 240V. The question is whether the saw was correctly converted to 240V. The 120V electronics would likely evaporate in short order if connected to 240V, so that isn't the issue.

I've never looked inside a Sawstop but the control electronics might have a universal power supply that can handle 120 or 240. The fact that they didn't blow *may* not mean he's in the clear. Then again, it might be, I just don't know. I DO know that there are many power supplies out there that can auto-adjust to either.

I do agree that it sounds like the motor isn't wired right. Check inside the box for the connections to be nice and secure.

Also... any change you have some really terrible blade alignment to your fence? Could it just be binding a lot? I can't imagine how much you'd need for this much effort but I think the other posters have the electrical troubleshooting pretty well in hand.

[Frank Pratt]

I've never looked inside a Sawstop but the control electronics might have a universal power supply that can handle 120 or 240. The fact that they didn't blow *may* not mean he's in the clear. Then again, it might be, I just don't know. I DO know that there are many power supplies out there that can auto-adjust to either.

Multi-voltage electronics are increasingly common, but the SawStop uses different control parts for 120V & 240V.

WRT power, my aforementioned piece of crap saw, it had a 3/4 HP motor & didn't have a problem cutting 4/4 hardwood with a thin kerf blade. Slow, yes, but doable.

[Mike Henderson]

I had an old Craftsman contractor saw with a small HP motor at one time. I had to be careful cutting anything thick - very slow feeding. When overloaded, the saw would stall but the breaker would not trip as long as I pulled the work back and let it spin back up again.

But maybe that was because the motor was so small - maybe it didn't draw a lot of excess current even when stalled. The motor in the OP's SawStop is 1.75HP which is about the biggest you can run on a 120V 15 amp circuit so when it stalls it may draw enough to trip the breaker.

With a thin kerf blade, that saw should cut 4/4 just fine. Even with a full kerf blade it should cut 4/4 fine. To diagnose it, I'd want to know the voltage at the motor and the amperage when it trips the breaker. I'd suspect a problem with the motor if the voltage is correct.

Mike

[Bert McMahan]

Ah good to know, thanks Frank.

[Melvin Feng]

all this talk about wiring makes me wondering if the plug is a 4 prong plug, and rather than use the two hots, it is using the neutral, but the motor is wired for 220v. I don't know if this scenario would cause the tripped breakers, but it would definitely cause the lower power. I don't know how inductive motors react to half of the expected voltage, but getting out a good multimeter would be an easy way to diagnose all of this.

I don't know if there is a way to measure the resistance of the coil windings, but another thought is that there could be a pinch or corrosion or something causing the resistance to be different than expected, causing problems with the motor.

[Bill George]

I downloaded the Owners Manual and it comes pre-wired for 120 vac with a standard plug to rewire to 230 vac is involved and hoping I can paste here. Motors do not need a neutral just two hot wires L1 & L2 and a equipment grounding wire. Once again the questions what size wire and what size circuit breaker?
BTW motors do run better on 240 than 120 volts. The saw Must be on a #12 wire or larger and 20 amp breaker dedicated circuit.

SawStopSniSmp.jpg

[Frank Pratt]

[QUOTE=Bill George;3073437]BTW motors do run better on 240 than 120 volts.QUOTE]

As long as the circuit is wired to code, that statement is completely false & a common misconception. A dual voltage motor has windings that are connected in series for the higher voltage or parallel for the lower voltage. Each winding sees the same voltage whichever way the motor is connected.

[Frank Pratt]

all this talk about wiring makes me wondering if the plug is a 4 prong plug, and rather than use the two hots, it is using the neutral, but the motor is wired for 220v. I don't know if this scenario would cause the tripped breakers, but it would definitely cause the lower power. I don't know how inductive motors react to half of the expected voltage, but getting out a good multimeter would be an easy way to diagnose all of this.

I don't know if there is a way to measure the resistance of the coil windings, but another thought is that there could be a pinch or corrosion or something causing the resistance to be different than expected, causing problems with the motor.

That's a good thought, but I doubt the 240V contactor would pull in on 120V. The motor will run, but will take a long time to come up to speed & be very lacking in power.