DC Control Circuit Fused?

[pressbrake1]

I like to protect any impedance load albeit coils on contractors or solenoids on fluid logic
Worked on a American machine that kept killing plc’s as they ran solenoids straight off the plc without a relay to protect it

 

[mtt.tr]

I like to protect any impedance load albeit coils on contractors or solenoids on fluid logic
Worked on a American machine that kept killing plc’s as they ran solenoids straight off the plc without a relay to protect it

very common, see it when contactors are replaced and the diode isn't reinstated. All coils are energy stores.

 

[Brad93]

very common, see it when contactors are replaced and the diode isn't reinstated. All coils are energy stores.

As we found the other week. Replaced with a proper Contactor with diode build in.

 

[Robotstar5]

I like to protect any impedance load albeit coils on contractors or solenoids on fluid logic
Worked on a American machine that kept killing plc’s as they ran solenoids straight off the plc without a relay to protect it

That's why you have flyback diodes across the solenoid coils

 

[pressbrake1]

That's why you have flyback diodes across the solenoid coils

It was beyond that the solenoids were huge, normal current was over plc ratings

 

[Robotstar5]

It was beyond that the solenoids were huge, normal current was over plc ratings

PLC I/O modules generally aren't designed to sink a lot of current so you would normally fit an interface relay although most manufacturers could supply relay output cards it would mean the end user carrying more spares.

I recall installing some spot welding robots at Ford Dagenham (for the first Sierras) where poorly interfaced welding kit would regularly blow the I/O cards on the robots, I think British Federal (welding kit) ended up footing the bill due to poor design on their part.

 

[MCKDAVID]

Be interested in knowing your industrial panel building and fault finding credentials

out of curiousity, what are yours @mtt.tr I may be wrong, but seem to remember you told us you were a cabinet maker? I may have wrongly presumed they were wooden cabinets and not electrical?

 

[mtt.tr]

out of curiousity, what are yours @mtt.tr I may be wrong, but seem to remember you told us you were a cabinet maker? I may have wrongly presumed they were wooden cabinets and not electrical?

That was a long time ago.


Last 10years have been mixed acquired mixed bunch of quals one benefit of being self employed, but primarily electrical work (I come from a long line of electrical engineers one day ancestors I'll get back inline ) that's been primarily testing and troubleshooting light industrial and domestic, this was mixed with running two sides of a business (self employed) tree work I liked the heavy plant side that allowed me to be involved in, it's a good excuse to buy machines. Aswell as the electrical work though for a while i was involved in full construction jobs but that was because it worked well with personal goals.

6months ago went employed taken on for my electrical experience mech/elec in one package seems rare as hens teeth outside this forum I have been mostly involved in breakdowns some servicing no particular brand of machinery.

I've just accepted a very well paid position, again mech/elec allowing me to achieve an engineering degree
That was a role I accepted out of alot of interest as I was in a position to decline a good few, some were headhunted some just through online CV

Must be doing something wrong I guess.

 

[MCKDAVID]

^^ wow, you must be about 90 years old to have managed all that.... fair play to you...

 

[mtt.tr]

^^ wow, you must be about 90 years old to have managed all that.... fair play to you...

Driven or dog with a bone.

Maybe a degree of obsession in 12years I can count my weekends and holidays off on my hands, you only get to pick your sacrifice

,the cabinet making was my rebellion to family heritage. Started before leaving school weekends/Evenings much appreciative to the kind sole that gave me an opportunity then a few years after college