I like my customer...

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ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
Got a call this morning. Motor on VFD won't start. Do a few checks and because drive won't even attempt to start up ask "Has anyone had their fat fingers in here?". Nope. Yea right. A bit over an hour later the confession of "Well, I guess Jake was in there." (Name was changed to protect the guilty)
 
brian john

brian john

Senior Member
Location
Leesburg, VA
Went to a site MCC bucket had blow up, I asked what happened building engineer says he tried to open the cover and it just blew.

Later my apprentice points to the trash can 6" screw driver in the can missing about 4"s of steel,.
 
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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I had a similar experience with an old portable concrete plant, they called and said the it just wouldn't do anything, found the control fuse blown right off, replaced it, still wouldn't run. They pulled out three different sets of prints on it and said it was wired by all three over the years. This plant was so old, there was no PLC's, everything ran off of a clock motor turning a cam with about 30 micro switches attached to it. About 30 minutes into troubleshooting it, I found the e-stop circuit was open, all of the e-stops were manually activated, but none was pushed. After telling the maintaince man there was an open in the e-stop circuit, he said "Oh, yea, I replaced the contact on that one over there this morning. He had replaced a normally closed contact with a normally open, not knowing there was a difference!
 
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ItsHot

Senior Member
Location
A little piece of heaven!
bldg. engineer

bldg. engineer

brian john said:
Went to a site MCC bucket had blow up, I asked what happened building engineer says he tried to open the cover and it just blew.

Later my apprentice points to the trash can 6" screw driver in the can missing about 4"s of steel,.
Click to expand...
"Building engineer" ...That's the guy that sweeps and mops the floors!
:D
 
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danickstr

Senior Member
don't they know to at least make an attempt to remove the evidence of their meddling? I learned that as a little kid.
 
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charlietuna

Senior Member
We learnt real fast to record all the VFD setpoints(in ink) on the back inside cover of the drive's tech manual! Something about computerized equipment that people just love to play with. We had an old Miller press that we converted to a VFD and the press's max speed was reached at 900 motor RPMs. So we programmed the maximum motor speed at 900 along with all the other perameters. Then locked the program with a code, which only the owner was told. And we explained to him how important it was not to change the setpoints! About a month later, they had a problem and the first thing we checked was the program--eveything was changed--with maximum motor speed at 1800 RMPs!!! The press would have walked through the wall!! The original problem was a micro switch on the press. We then reset the setpoints and reset the entry code and didn't tell anyone!!!

On switchgear--we were called out to a large building to find a blown 800 amp fuse??? We couldn't locate the cause and were puzzled, then one of the building engineers showed us what was left of a paint brush. Luckily the brush's operator had a three foot stick taped to it as he was sweeping out the dirt inside the main switchgear. He forgot that the top of the brush was wrapped in sheet "METAL"! :cool: His boss told him to clean out the switchgear room!
 
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