Overload issue

[Pete999]

You say the machine's a year old...….surely it's still under some warranty with the suppliers, from your point of view. I would have thought they'd have maintenance engineers at the ready if it's that new.
How much did it cost? If there are 10 motors involved, it must decent sized.
Your firm must have come across problems before.

Could be, the Machine has been incorrectly specified from day 1.

 

[edexlab]

Possible but it looks modular ie add sections to make bigger system, I've seen other systems they have done and they look identical

 

[ipf]

This is third party equipment sold as a package for complete system,

My company (Dutch) builds the main machine, that feeds product to the conveyor I work for UK service dept, this conveyor is built in Germany
I'm here as first response to the warranty, as the OEM is abroad its easier for us to attend first

They're sending a Senior Engineer today
However it's been running fine today no stops for 6 hrs so far which they haven't had for several weeks usually runs for between 30mins and 2 hrs before its stopping

Fair enough. You seem to have got there, to some degree.
It just seems a bit pointless asking on the forum when you are part of the maintenance team. You probably know more about the unit than the rest of us put together.

 

[edexlab]

I don't usually work on this equipment but it's just a conveyor with motors so nothing special
The point of the thread is that I think I have found the problem and tested/ investigated any possible causes all of which have pointed back to the same thing,

I'm still relatively new to Automation having learnt as I go and am looking for anything I might have missed that can be checked

Another more qualified engineer ( German) has cast doubt on my findings even though he's actually complimented me on how I recorded all the details
and to me is ignoring the facts to the point he's sending a guy here to check for supply problems

 

[ipf]

I'm still relatively new to Automation having learnt as I go and am looking for anything I might have missed that can be checked

Another more qualified engineer ( German) has cast doubt on my findings even though he's actually complimented me on how I recorded all the details
and to me is ignoring the facts to the point he's sending a guy here to check for supply problems

Geeermans!……...I had one on the phone from the Fatherland, years ago, telling me I was wiring star delta starters wrong on some new spray booths, they were tripping on changeover. It was a load issue. I'd temporarily upgraded the starters without them knowing (client didn't want them to) and they were working perfectly. Faxing drawings to show me how to wire 'em……..cheeky b**ger.

 

[edexlab]

I actually like most of the Germans I've met and like the way they live in the South of the country, I think they still have good values and lifestyle there

Don't understand the shouting though!!!

I've just spoken to him he is back pedaling now asking if I still think the Engineer should come or not.......

I only asked them to send a few parts not an Engineer

Maybe something got lost in translation he says,

But his English is better than mine and that's only because he has a German accent!

Guys on the way to the Airport now I spoke to him he is coming anyway as he wants to look at the site for the next machine installation
Apparently it's his Dad that's coming
He's the owner of the company!

 

[ipf]

Geeermans!……...I had one on the phone from the Fatherland, years ago, telling me I was wiring star delta starters wrong on some new spray booths, they were tripping on changeover. It was a load issue. I'd temporarily upgraded the breakers without them knowing (client didn't want them to) and they were working perfectly. Faxing drawings to show me how to wire 'em……..cheeky b**ger.

Correction Upgraded the breakers.

 

[FarmersFriend]

Check that the contractors are correctly rated for switching of motors under load, (AC3/AC23) I have found panel builders use the wrong componanrts.
As the overloads are thermal the heat from the contactors can cause problems, you could use remote mountings for the overloads to move them away from the contactors.

 

[edexlab]

Ok bit of an update
Yesterday 2 new overloads fitted didn't have any stoppages all day until the conveyor got jammed ( that's another issue being dealt with)

I'd just checked the relay and overload voltage and continuity, current and temperature etc as I was keeping tabs on it

Cleared the jam gave it a few minutes to cool and switched back on again

I noticed the solenoid lever went across as normal then after a second or two it moved a few mm to the right, this hadn't happened before
Looked like it was on but clamp meter told me it was fluttering so I checked the coil which was ok but the contacts were starting to change colour from heat and some arcing spots were visible, I compared it to one next to it which was switching slightly less than this one, big difference in appearance

So I think instead of the usual story of arriving and something had failed,

I got to see the problem while it was failing

German Engineer agreed with me today after checking things through himself that that the PLC needed a longer delay between switching and he is going to trial some higher duty relays here and if it proves reliable change the spec on his conveyor systems with the same spec as this

He said normally their systems are several hundred metres with upto 200 motors but as these are longer, there is less switching of motors as there are buffer areas preventing more than 3 boxes on any section at any time