SawStop CTS trigger due to "electrical noise"

[Ian33a]

I recently purchased a SawStop CTS and found that the blade brake actuated on something like the third cut. Being convinced that I hadn't touched the blade while sawing, I sent the cartridge back to SawStop (who have been very helpful) and after sometime they said that the cartridge had actuated due to "electrical noise". This is a rather concerning outcome as it could be quite difficult to work out what is causing the "noise". I asked if SawStop could send me suitable application notes or bulletins which I could use to try to work out what noise the saw might be prone to trigger as a result of. SawStop contacted their support people and said that I should change the brushes and that they would order me some new ones as well as send me a replacement activation cartridge.

As the saw is brand new, I'm a little dubious that brushes are the cause, but I am more than willing to give this a try.

Like many people, I am a hobby user doing occasional woodwork using a single phase supply (ultimately from the consumer unit in my house) in my workshop in the UK. The supply feeds several outlets - with only a single tool running at any given time (plus dust extraction). I don't have the luxury of three phase or electrical line filtering.

Has anybody experienced a trigger like mine and what did you do to reduce the chances of a repeat - and has your solution been successful?

Many thanks

 

[luvmytoolz]

It's entirely possible the brushes could be an issue, or that there was some issue with the brake itself, but I think in general "electrical noise" tends to be the universal catchall for unknown causes. Most countries have EMC requirements on any mains devices that state they "must not cause and must be able to receive or withstand electrical interference" without impacting the operation of the mains powered device.

Static electricity due to dryness/humidity may also be a factor, as is a possible leaky or faulty earth. Maybe try one of those simple and cheap mains plugin testers that indicate via LED's if there's an issue with the mains or wiring.

However, this may have been a one-off thing that may possibly never occur again and you may never find out what the cause was.

 

[Coen]

How is the grounding? The typical old home ground rod that uses [was/has been] as pronouns?

 

[luvmytoolz]

How is the grounding? The typical old home ground rod that uses [was/has been] as pronouns?

This was part of the issue I had in the shed with some more sensitive equipment, I found we had multiple earthing points causing ground loops. Since getting the whole place rewired, no issues.

 

[guybo]

Hi, welcome to the fog, I heard this same complaint from a few owners, this video sums up their pain.

 

[ChuckS]

His alternative seems to be to use a non sawstop saw and face the risk of serious injuries because the no. of activations was too many and too costly. Only he can decide which route would be less costly.

 

[luvmytoolz]

His alternative seems to be to use a non sawstop saw and face the risk of serious injuries because the no. of activations was too many and too costly. Only he can decide which route would be less costly.

Given it seems most of the activations were from metal and moisture/sweat contact, I'd be paying the rent and just being extra careful to not trigger it accidentally.

When it comes to losing a digit or especially worse having an employee suffering serious injury, the rents the far cheaper option. Losing a finger isn't just an injury condition you get over pretty quickly, even many years later if you hit it against something the pain can be unbelievable!

If you think you can benefit from it, pay it.

 

[Coen]

His alternative seems to be to use a non sawstop saw and face the risk of serious injuries because the no. of activations was too many and too costly. Only he can decide which route would be less costly.

Well, if you get too many false activations, costing a new blade and cartridge every time... you need to work for that. Sleeping more and being more awak when working saves on accidents in general.

The number of Americans visiting a hospital each year for table-saw related injuries is about the same as the number of Americans that die in traffic each year, just to put it in perspective. And not all those injuries would be prevented by SAWstop technology in the first place.

And if the false activations are caused by faulty grounding... that is an easy fix.

 

[Tom the Remodeler]

I will make the obligatory suggestion that you consider ripping with a bandsaw. While I do have a table saw (Euro-style sliding saw), I can't remember the last time I ripped anything on it. All rips are performed at the band saw or with a track saw, and if the edge needs to get cleaned up I have a multitude of options (jointer, thickness planer, hand plane, use shaper or router table as a jointer, etc....).

A properly configured bandsaw with a sharp blade and proper in-feed and out-feed support should be able to rip circles around a cabinet-style table saw, in a much safer manner (no risk of kick-back, easier to use push blocks, etc...).

Of course we all have our preferences when it comes to working techniques, I am of the opinion that the traditional cabinet style table saw is vastly overrated, and generally not needed in most shops, you just need to re-think your working processes and supporting equipment.

I hope you're able to identify a solution which works well for you, be safe out there!

 

[ChuckS]

I will make the obligatory suggestion that you consider ripping with a bandsaw. While I do have a table saw (Euro-style sliding saw), I can't remember the last time I ripped anything on it. All rips are performed at the band saw or with a track saw, and if the edge needs to get cleaned up I have a multitude of options (jointer, thickness planer, hand plane, use shaper or router table as a jointer, etc....).

A properly configured bandsaw with a sharp blade and proper in-feed and out-feed support should be able to rip circles around a cabinet-style table saw, in a much safer manner (no risk of kick-back, easier to use push blocks, etc...).

Of course we all have our preferences when it comes to working techniques, I am of the opinion that the traditional cabinet style table saw is vastly overrated, and generally not needed in most shops, you just need to re-think your working processes and supporting equipment.

I hope you're able to identify a solution which works well for you, be safe out there!

Frankly, I have never come across a bandsaw on any job sites. Even tracksaws aren't so common among contractors here. Almost every kitchen or home renov guy I know or saw doing their jobs here uses a portable table saw and a miter saw in their trade.

 

[Tom the Remodeler]

Frankly, I have never come across a bandsaw on any job sites. Even tracksaws aren't so common among contractors here. Almost every kitchen or home renov guy I know or saw doing their jobs here uses a portable table saw and a miter saw in their trade.

Hi Chuck,

You're correct that, for job-site conditions, you'll mostly find portable table saws and miter saws. Since it sounds like Ian is working from home, I suspect that a properly tuned 14" band saw with a suitable blade and removable in-feed and out-feed supports (Aigner, RUWI, Felder, etc....) would take up a smaller footprint and be much safer than a cabinet-style table saw, since even the SawStop doesn't control for kick-back and other saw hazards unrelated to flesh/blade contact.

I've been working on-site on a basement remodel most of the last month, so I have been forced to rip on a table saw (Erika 70). The Erika is an awesome saw, but if I anticipated more of this on-site work in my future I'd seriously consider something like the little 10" Laguna band saw for ripping: https://lagunatools.com/classic/bandsaws/v10-bandsaw/

As for track saws on job sites, it really depends. On mid- to higher- end remodeling projects I'd say they're pretty common, though I can only speak to my personal experiences.

 

[Crazyraceguy]

False triggers just occasionally happen. I don't know what really causes it, probably a combination of things.
I have had it occur when cutting PVC sheet, which has static buildup possibilities. I have had it happen when cutting thicker hardwood, where the only difference was the load against the motor, and it has been purely random. Over the years, I have sent close to a dozen cartridges back to them, with various responses.
This was all in a large cabinet shop, encompassing 9 different saws, and a nearly 18 year time period. The first one was in a borrowed temporary shop, in 2008. I have had it happen to me, and reset the machines for literally dozens of other employees. Sometimes it will go a very long time, others can happen within days.

 

[Tom the Remodeler]

I realize that Ian is a hobbyist, but in a larger Shop setting I can see the value in the newer no-cartridge, non-destructive systems now available from SCM, Altendorf, Felder, etc... No need to replace the cartridge, no need for a new blade, just re-set the machine and get back to work

 

[Crazyraceguy]

I realize that Ian is a hobbyist, but in a larger Shop setting I can see the value in the newer no-cartridge, non-destructive systems now available from SCM, Altendorf, Felder, etc... No need to replace the cartridge, no need for a new blade, just re-set the machine and get back to work

Absolutely, but those weren't around back then, and there are three of them to replace. That gets spendy too.
Besides, I'm out, it's someone else's thing to babysit.

 

[ChuckS]

My guess is that the majority of table saw finger injuries happen in settings outside the commerical/industrial environment. So those top-of-the-line finger-saving machines are the best but at the same time, don't really benefit the mass users.

When I bought my SS PCS about 12 years ago (my first SS experience was with an ICS 220V 20 years ago), I thought about getting a spare cartridge. I didn't and luckily, no activation has ever happened to my saw. I don't think I'd ever want to work any table saw that is not a SS now after 2 decades of being a SS owner or user.

 

[Michael Kellough]

I am a big supporter of SawStop but not an owner. But since Chuck has gone 20 years without an activation on his SS you could say he didn’t need it. He obviously already had proper safety practices down pat. But for the rest of us, you just never know.

 

[ChuckS]

Michael,

You really hit the nail on the head because I did wonder if my investment in the PCS was a little waste of money. Eventually, I looked at it as insurance premiums.

Of course, the saw is well made and cut quality and consistency are amazying. Like the Kapex, it has the best dust collection feature among table saws (provided the overarm dust collection tube is connected directly to a vac or extractor).

 

[onocoffee]

Finish Carpentry TV said:
"We've really only had this save one person - the other eight hundred dollars was like, somebody sweat on it."

While I certainly can empathize with the pain of $800 in expense - he said it himself: it already saved one person. From one of the tablesaw injured woodworkers I met, it cost him $68,000 in medical bills when he ran his hand through the blade. He's still $67,200 ahead of the game.

 

[onocoffee]

I will make the obligatory suggestion that you consider ripping with a bandsaw.

This just reminded me that perhaps I should be doing more ripping this way. Just before the weekend, I was working on a small serving top and ripping white oak on the table saw. Turns out it had a lot of internal tension and started binding. So much so that I stopped the cut and shut off the saw, pulled it out and finished the cut with the track saw.

The bandsaw would have been less problematic because I've experienced lots of tension even while using the track saw.

 

[luvmytoolz]

This just reminded me that perhaps I should be doing more ripping this way. Just before the weekend, I was working on a small serving top and ripping white oak on the table saw. Turns out it had a lot of internal tension and started binding. So much so that I stopped the cut and shut off the saw, pulled it out and finished the cut with the track saw.

The bandsaw would have been less problematic because I've experienced lots of tension even while using the track saw.

I pretty much all the time find the bandsaw by far to be the easiest for bulk and/or rough ripping and preparing stock for finish machining. It does it with ease and if the stresses cause it to bow, it won't affect the bandsaw or the operation.