Fire!!

[Ken Sully]

As a new user of Shopbot I was cutting hold downs in my spoil board. Everything going well...until the last one. Kept hearing about being careful about .350 not 3.5 and that is what I did. As soon as it it went down I stopped it. Very small burn mark in my spoil board so fixed the z and kept working.
I thought why do I keep smelling smoke? To my surprise it was the dust collector and a smoldering pile of ash being fed by the collector. No damage other than my pride, but never thought such a tiny black mark on the spoil board could have led to a bigger problem. My lesson even the smallest whoops shut everything down check the collector.
This may have been posted before..... but just couldn't keep it to myself.

Every day is a learning day

[coryatjohn]

I have temperature sensors on pretty much everything. If certain limits are exceeded, the system affected shuts down. Fire is unlikely but when it happens, it can really ruin your day.

[myxpykalix]

This is why i rarely use a dust collector (ironically only for mdf) because do you remember starting a fire as a kid you would blow on the embers till it poofed out to a flame? This is the same thing and you could have a fire brewing under your material and not even know it. There have been a few guys who have posted pictures of burnt tables.

Always have a fire extinguisher handy anyway and remember the old saying..."where there's smoke, there's fire!"

Just know you aren't the first "newbie" to do something DUMB....(just ask Harry Ball):rolleyes::eek:
We've all done them...there's no shame here! (maybe a few chuckles tho...:D)

[Bob Eustace]

Ken as a result of the great advice on this forum I stuck our dust collection outside the workshop. Before closing up each night I religiously check for smoke in the enclosure. I have a dedicated fire hose outside as well as inside. Every morning I unlock the enclosure door for easy fast access in an emergency. Also have the isolator switch just outside the enclosure. Think I might add Johns idea of temperature sensors.

[coryatjohn]

Ken as a result of the great advice on this forum I stuck our dust collection outside the workshop. Before closing up each night I religiously check for smoke in the enclosure. I have a dedicated fire hose outside as well as inside. Every morning I unlock the enclosure door for easy fast access in an emergency. Also have the isolator switch just outside the enclosure. Think I might add Johns idea of temperature sensors.

Look for resetting thermal fuses. They're about $10 each depending on the temperature range. Use a magnetic switch to power things and run the power for the relays through the thermal fuses. The magnetic switch makes sure that once power is cut, it won't come back on when the fuses reset. It's really a simple setup.

[Bob Eustace]

Thanks John - will follow your advice.

[dana_swift]

John- I may steal the thermal fuse idea. Thats a good one.

D

[jTr]

For those of you using the lighthouse style vac motors for hold-down, they will overheat when bearings start to go. I've used a simple $10 indoor outdoor thermometer - put the remote outdoor sensor directly on vac motor so I have a visual on how their doing. This allows me to control venting during normal use: if temp climbs above 115 degrees = open another zone to bleed a bit more/reduce temp.

However, I am intrigued by John's concept as well. Thanks for sharing that!

jeff

[curtiss]

I have temperature sensors on pretty much everything. If certain limits are exceeded, the system affected shuts down. Fire is unlikely but when it happens, it can really ruin your day.

Where do you buy these sensors ? Where do you locate them in the dust collector system ?

thanks

[coryatjohn]

Where do you buy these sensors ? Where do you locate them in the dust collector system ?

thanks

There are several different types and each has a temperature that it kicks off at. I got all of mine from eBay from various suppliers. Just search for the term "resetting thermal fuse" to find them. You can also go with standard thermal fuses that blow permanently. They are cheaper. You also won't need a magnetic switch in that case.

[myxpykalix]

John,
I've been reading this thread about your sensors so let me ask you this...Do you have them set up so that if they sense a temp increase they shut EVERYTHING down?
It would seem to me that it would be better to set them up on some type of emergency type light/sound so that alarms so that in case of a false alarm you don't lose all your work.:confused:

[coryatjohn]

If the temperature limits are reached, something is wrong. That's the theory anyway. It could easily be setup with multiple sensors so that there would be a warning. I didn't go to that level though. Shutdown is good enough for me. I don't do customer work so the only one who would have to deal with it is me. When it is triggered, a red light on the console lights up so I will know why everything suddenly got quiet.