SawStop Pro Electrical Issues - Tripping

[Dustin DuPrat]

I've had a SawStop Pro 1.75hp 220v saw for approx. 5 years now. From day one it tripped frequently - both the breaker as well as the thermal in the saw, especially when cutting hardwood. Even with a fresh Freud Glue-Line blade it has a super-tough time cutting 4/4 kiln-dried maple/birch, even walnut and poplar seem to be a chore with it tripping frequently. 8/4 anything...forget about it. We regularly have our blades sharpened, we use the appropriate blade for the corresponding materials/applications and don't cross blades from materials like MDF and melamine to plywood and solid wood. If blades appear contaminated we give them a quick wipe down to lower friction and buildup. We're pretty fastidious with our methodology and tools.

With that said, I've spoken with SawStop reps and they insist that it's either operator error (wrong blades with the wrong materials) the speed at which we're feeding the material (I've been doing this for 20+ years) or most likely, the way it's wired in our shop. They've indicated that they personally have these saws in their home shops and that they experience little trouble if any in the circumstances suggested. I've had multiple electricians look at our setup, read the literature, specifications etc and all insist that the way it's wired is above and beyond adequate. I've gone through more blades at $100+ each thinking maybe the sharpeners missed the boat and did a shoddy job, though they've worked perfectly on our other saw(s).

The saw and it's behaviour seems to cycle: some days if we're ripping hardwood it'll trip the breaker upwards of 20 times (yes, the breakers been replaced 4 times now to ensure that it isn't faulty) other times it'll kick the thermal as many times...and when I say 20 times I'm not talking during the duration of an 8 hour work day, I'm talking over the length of one 8-10' board that's already been trued on the jointer and planed. The saw doesn't have any reason to labour to the point where it's kicking - and with that said I had a 40+ year old Delta with a belt-driven 1.5hp motor that operates more reliably, as will my DeWalt job-site saw.

Both shops I had/have the saw in are climate controlled and dry. Dry material is only ever cut. The saw is cleaned frequently with compressed air and brushes. It's also hooked up to full dust collection from the cabinet base as well as the large SawStop over-arm collection system. I can't see anything situational based on settings that could be contributing to this issue.

Am I missing something here that SawStop isn't telling me, or even an electrician? SawStop had us replace the contractor box...didn't help a bit. Now they're MIA and likely sick of hearing from me as this has been an issue we've struggled against pretty much from day one. Any feedback from individuals with this saw - similar or contrary would be great peace of mind. I'd love to know - even if it's just me having this issue!

Any advice would be greatly appreciated, especially before I face what seems to be the inevitable and go down the route of investing in another costly saw.

Thanks in advance!

[Andrew Seemann]

Have you ever had an electrician there when it was tripping? It possibly could be that you are getting low voltage periodically in your shop. It is unlikely but possible. That would have the effect of increasing the amp draw and could make the motor run hotter as well. Ideally you would check the voltage to the machine when it is running right before it trips to see if you are getting at least 220 or so volts.

[glenn bradley]

with that said I had a 40+ year old Delta with a belt-driven 1.5hp motor that operates more reliably, as will my DeWalt job-site saw

I don't know about the Delta but the DeWalt is certainly running on a different circuit. The draw may not be all that different due to the higher voltage on the Saw Stop. With the breaker replaced that would lead me to the wire and the connections. I forget how often one should torque breaker connections and I have to admit I have only done it when moving into a new space or when a problem presents itself. I certainly have found loose connection points during those efforts.

I would like to hear from someone who has many years in the electrical motor field since by comparison, my experience would be minor. I have not had an induction motor, that I know of, present wide swings in amperage draw. Unfortunately using the "which one tripped first" method of troubleshooting isn't super helpful. Is it possible to run the saw on a different circuit when it is doing its trick? Maybe just pulling the 220 kit and going back to 110v could be your fix.

[Andrew Hughes]

I was thinking the same thing as Andrew S. If it were my saw I’d be looking at how many Amps the saw was pulling before it tripped. It must be going over it’s Fla. Voltage sagging is very common for me here in So Cal. I think we have the dirtiest power and politicians.
During the summer when I start my big bandsaw the voltage drops from 235v to 112 and the lights dim. Thankfully it’s not very long.

[Paul F Franklin]

As I'm sure you know, that saw should have no problem ripping 4/4 hardwood.

I would verify that the motor is getting 240 volts--at the motor terminals--when it is operating under load. If it is, you have a motor problem, either an incorrect value run capacitor, a bad run capacitor, or a bad motor.

Another thought....if that model can be wired for 240 or 120, make sure it's wired for 240.

[Bruce King]

Describe the wiring path and sizes from the receptacle all the way to the outside meter.
Pictures of each panel and the meter too.

[Dave Mills]

I've had a SawStop Pro 1.75hp 220v saw for approx. 5 years now.

To my knowledge the 1.75hp PCS is a 110V machine. Or did they make a 220V version 5 years ago?

[Richard Baxter]

Get an amp probe and check amperage as you are running the saw. 1.75HP to me is too small especially cutting 4/4 hardwood. Minimum should be 3HP

[David L Morse]

Your troubleshooting to date strongly points to the motor, not the breakers, nor the saw's overload protection. (The multiple tripping is caused by the long time constants of the protection devices. That's by design, it's not an issue.)

Some questions:

Who did the 240V conversion? (According to the SS website 120V is standard and a conversion kit is available)

Did your multiple electricians check the wiring at the motor, not just the switch box?

Does the saw slow down when cutting the 4/4 material? (in case you're a musician, the change in pitch from no load to full load should be less than a semitone)

A request:

Get an ammeter and check the idle (no load) current. If the saw will allow it, take the blade off for that test. No real need to check loaded current, we already know that's too high.

A comment:

If you've been operating the saw this way for five years the motor likely does not have much life left. That's a lot of time spent at an excessive temperature rise. Aging rate approximately doubles with every 10°C increase in temperature.

[Brian Tymchak]

Any chance you have an undersized extension cord run to that saw?

Edit: I guess in retrospect that wouldn't explain the breaker tripping.

[Brian Tymchak]

Get an amp probe and check amperage as you are running the saw. 1.75HP to me is too small especially cutting 4/4 hardwood. Minimum should be 3HP

Not sure if you are saying that generally you need a 3 hp saw to cut 4/4. If so, I disagree. I've been cutting 8/4 hardwoods on my 1.5hp Ridgid TS3650 for 10+ years.

[Bill George]

Having been in the electrical trade since 1962 and retired as a master in 2007 I can safely say I have been around a while. There are electricians who wire houses and I was not one of those. I did commercial and industrial.

What size wire and what size breaker feeding the motor?

Is it on an extension cord? If so what size wire and how long a run?

[Bill George]

Any chance you have an undersized extension cord run to that saw?

Edit: I guess in retrospect that wouldn't explain the breaker tripping.

Yes it will. Undersized or long cord would cause excessive volt drop on start up. Motors draw 3 - 4 times FL rated current on start up. The breaker or TD fuse Usually has enough time delay built in to allow the motor to start, IF the voltage says constant, or nearly so.

[Tim Nguyen]

I have the PCS 1.75 and have no problem once I moved my plug to a dedicated 110 volts 15 amp service. I suspect you are not using a 220 volt circuit. Does anyone know what style SawStop 220 volts plug looks like? I suspect the plug to have a different configuration from a standard 110 volts and can not plug into a 110 volt outlet. If you have a 220 volt service, than I would suspect the saw first.

[Thomas McCurnin]

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.