Starting the week with a bang

[Jeff]

This morning at about 5:59 AM I pushed the little red button to start the headsaw. That little act set in motion quite a show. First the explosion, then the fire, then all the lights went out. Or did the lights go out first?  Whatever order it happened, the panel box just below and to the left of the sawbooth that contains the 440 volt starter for the headsaw had two of the feed wires short together. It blew the cover off the box and the molten aluminum wire sprayed the outside of my Hydraulic tank setting the film of oil and sawdust instantly ablaze. The short instantly tripped the main breaker. Never before have I seen a main feed breaker trip.

We got the fire out in short order, I then restored power to the building. The explosion melted the aluminum wire in two of the starter lugs, so after a search I found some replacements in one of our retired gangsaw panels. There was just enough wire to pull down and reattach everything. I then replaced 2 of the 3 200 amp fuses that blew (the 2 legs that shorted) and was back running by 7. Interesting start to the week.

[Bibbyman]

Glad nobody got hurt and the place didn't go up in flames as sawmill tend to do.

Late last spring we blew a couple of 110 amp fuses to the 25hp 3ph motor on our Wood-Mizer.  It was nothing like what you discribe.  In fact,  we didn't know it happed - just that the motor wouldn't start.  We called Sparks (it was on Saturday morning and he was in keeping us covered) and he walked us throught some checking and went back to the main disconect to that motor and checked the fuses. Sure enough,  they'd blown.  Don't know why.

[ARKANSAWYER]

  MERCYSAKES! and on a Monday as well.
  Back in '95 I had a 480 3p to 110 1p transformer blowup on me.  Third degree burns on left hand, 2nd on face and right hand and could not see for several hours.  It tripped several feed breakers and luckly for me one for the conveyor on the head rig.  They went looking for the cause and found me laying on the floor smoking.  We were lucky as well as the fire was easy to put out.
  Hope the rest of the week goes better.  Now I know why mills never throw any old equipment away.
ARKANSAWYER

[Ron Wenrich]

I know our maintenance engineer checks out the lugs in the box periodically.  He says they have a tendency to loosen up due to all that juice pouring through, especially on startup.

[woodhaven]

I think the guy that invented aluminum electrical components should be shot. I guess they have there place somewhere. I know its a lot cheaper but the damages arn't worth it. I have seen so many electrical problems and fires over the years and a lot are related to aluminum electrical components and wire. I have tried to get the power company out to my place to turn off the power at the pole so I can tighten all the lugs. No go. I guess they rather wait till the meter base blows off the side of the shop or house and everything burns to the ground. I have never seen a aluminum lug that hasn't come lose after a few years in service. It might be a while before there is a problem but it is just waiting to happen

[D._Frederick]

Jeff,

It sounds like you should pull-in some new wire to get service loops in the main panel and the starter box. The current impluse causes the wires to flex, without the service loops, there is additional strain on the lugs. Aluminum has the bad habit of "cold-flowing" so the lug bolts should be re-tightened, depending how many heat cycles they go though.

The person who designed and wired the sawmill did a good job, the mishap did shut the power off and prevented a big fire.

[OneWithWood]

I bet that got your heart thumpin'