Timing

Learn the NEC with Mike Holt now!
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Not open for further replies.
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
7:15 PM dark thirty here. Call from customer with spud harvesting equipment we customized 10 years or more ago. A generator they use died a couple times this afternoon. They thought a VFD had failed so they changed it. Wondered if I knew the parameters that needed changed. I laughed and told them to touch nothing, maybe put the old drive back in. I sent the only guy in the state
that remembers anything about it. I did the logic and we both tugged and pulled wires but I haven't been back since. We did two systems. The only two like it anywhere, I'm sure.

My question is why in the heck do you, the customer, spend a couple hours throwing parts and time at something when you have absolutely no clue?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I get that sometimes, usually residential customers. The same ones who flip every breaker in the panel for a burned-out bulb.

Or buy new dryers because the old one ran but didn't heat, then the new one does the same thing because of a bad breaker.

Some replace GFCIs, switches, lights, or whatever they can with a screwdriver, because they don't know how to troubleshoot.
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
7:15 PM dark thirty here. Call from customer with spud harvesting equipment we customized 10 years or more ago. A generator they use died a couple times this afternoon. They thought a VFD had failed so they changed it. Wondered if I knew the parameters that needed changed. I laughed and told them to touch nothing, maybe put the old drive back in. I sent the only guy in the state
that remembers anything about it. I did the logic and we both tugged and pulled wires but I haven't been back since. We did two systems. The only two like it anywhere, I'm sure.

My question is why in the heck do you, the customer, spend a couple hours throwing parts and time at something when you have absolutely no clue?
And it now takes twice as long to fix, trying to figure out what they did and deal with "no we did touch that" and you know it was obvious they did.
 

MD Automation

Senior Member
Location
Maryland
Occupation
Engineer
He got it up and going. Customer didn’t get VFD control wires in correct spots.

Tom, good for you to troubleshoot and fix so quickly!


And it now takes twice as long to fix, trying to figure out what they did and deal with "no we did touch that" and you know it was obvious they did.

Ha ha Fred - in my business those are called "Buddy Bugs"! Not the original underlying problem, just a bonus one(s) added by mis-guided troubleshooting. You arrive onsite to look over a problem and find something crazy mis-wired or the wrong part inserted and wonder how the heck it ever worked to begin with. Come to find, like you pointed out, that was the site's first attempt at repairing it themselves. Made it 2x worse, then call for help while claiming they never touched anything.

Quick story I hope will get a chuckle from some of you - and totally true. Years back, dealing with unusual behavior on a large sorting machine (think football field sized) and working for a few days with onsite techs going over symptoms and various troubleshooting attempts. The site swears the trouble started out of the blue. Finally give up and fly out and ask, for the hundredth time.. "When did this problem start, again?"

Somebody then blurts out ... "It was right after we ran into that section there with the forklift!"

Sigh.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I recently had one where the VFD died, so they put in another. It died, so they put in another. After the 4th drive died, THEN they called me...
They checked your rates and figured (3) drives were cheaper :) (joke)
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
They checked your rates and figured (3) drives were cheaper :) (joke)
Blowing that kind of money generally requires some upper management clown to stick his oar in, usually without really understanding how much it costs.
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
I recently had one where the VFD died, so they put in another. It died, so they put in another. After the 4th drive died, THEN they called me...

The good thing is, by that point, you know you don't need to troubleshoot the vfd, becuase they've already tried that several times.

"Thanks for narrowing it down for me fellas, but I know an easier way....." :)
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I recently had one where the VFD died, so they put in another. It died, so they put in another. After the 4th drive died, THEN they called me...
The IT equivalent back in the days of the monster removable disc packs was the head crash, which almost always damaged both the head assembly, which is part of the drive, and the surface of the removable pack involved.
Before calling in factory support the customer swaps packs around trying to get something working and ends up with all their drives and packs destroyed.
Sometimes including their backups.
 

drcampbell

Senior Member
Location
The Motor City, Michigan USA
Occupation
Registered Professional Engineer
We kept a crashed pack and head assembly for breaking in new guys. We'd install them into a drive that wasn't in use or was otherwise dead and ask, "What do you think? I think the disc is shot."
Damn straight a disc was shot. After the head crash, we took it to the rifle range and shot it.
 

StarCat

Industrial Engineering Tech
Location
Moab, UT USA
Occupation
Imdustrial Engineering Technician - HVACR Electrical and Mechanical Systems
This guy I work with takes an old turntable assembly out of one fo those old consile stereo systems, and is wanting to adapt it to? something so he can play records? He brought it to me after he had wired it up and applied power. He had created several direct shorts by taking leads on the phono and amplifier circuit such as would have ported to RCA jacks and wire nutted them together. No plan, no anything, just lets randomly tie a bunch of wires together and expect it to " work." I told him it might have been rescued until you powered it up.
 
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