OT... Hydraulic Solenoid Burning Out

[mendonsy]

I agree with most of the above comments. Something, probably debris, is causing the valve to stick and resulting in high current.
The chances are that replacing the valve will solve the problem, but if the hydraulic oil or lines are contaminated you can expect more failures.

 

[baldone]

I am guessing the relay output for the opposite coil is sticking cause power to both solenoids.

I would think about replacing your PLC output module.

 

[rigicon]

I had lots of problems with relays on Hydraulic circuits. Adding suppression does help. Eventually I replaced the relays with Solid State relays that had built in suppression. Never looked back. As for dirty oil one would need to filter and change hydraulic oil on a PM. Spools getting stuck can't do your process any good. Another thing with control of Hydraulic oil is maintaining a nice constant oil temperature.
Just my 2 pence.

 

[sbaum]

So it is something in the hydraulic system.

I was out last night and changed the complete valve assembly again. The previous one only worked for a day before burning out.

After monitoring it for a while I actually saw the coil draw 4 times the current and the cylinder wasn't moving...
Something is definitely causing the spool to stick.

I'm turning it over the the mechanical guys now.

Thanks for all the help and info.

 

[strantor]

So it is something in the hydraulic system.

I was out last night and changed the complete valve assembly again. The previous one only worked for a day before burning out.

After monitoring it for a while I actually saw the coil draw 4 times the current and the cylinder wasn't moving...
Something is definitely causing the spool to stick.

I'm turning it over the the mechanical guys now.

Thanks for all the help and info.

at the point when it was drawing 4X current, did you also check to make sure that the opposite solenoid was OFF?

 

[Fredlaroche]

It really seems to be the hydraulic. You said you were replacing the entire valve assembly so you may want to look outside the box here. It may not be the spool that's stuck. It may just be something preventing it from moving. An obstructed Drain or Pilot line COULD cause this. Also, while I think this is a bit far fetched, you may want to check the contamination level of your hydraulics.

Hope this helps! Will be looking forward to read what you found out.

 

[James Mcquade]

Fredlaroche,
not necessiliary.

if the other solenoid contact is sticking or broke, you will get the 4x current while trying to energize.

dirty oil and contaminants will definitely cause a problem.
if there are contaminanents, drain the entire hydraulic system,
flush with new oil for several hours (25 micron filter or half of what a standard valve is), replace oil and filter, run for several days, replace filter with a standard one.

that's what we had to do.

regards,
james

 

[shooter]

check the spring inside,
is the plunger correct working?
is the o ring good?
is the pressure return not blocked (small hole on baseplate)
is the other coil (reverse) good
is it manual working?
dirt is causing the very small holes in the diafram and the baseplate jamming so check them.
is the o ring in place under the coil
do this all with a current meter in hand as it is obvious the plunger is not moving.

 

[spice_miner]

I just recently had a coil go bad on one side of a dual coil solenoid like you describe. I ordered a new coil using the numbers on the side of the solenoid. I was blowing fuses shortly there after. Long story short, they sell a solenoid with two different TYPES of coils. One is a low wattage coil and the other a high wattage coil. The difference being that the low wattage is for an application that would keep the coil energized for an extended period of time. The high wattage coil operates the spool better but it gets hotter and will pull much more current. I'm just saying.....

Do a google search for "Silt Lock, Hydraulics" and it will explain how an ac coil will pull a boatload of current and likely burn up if the spool isn't moving freely. I was skeptical at first but it makes perfect sense.

 

[Sidewinder]

This valve is wet armature too.

 

[rigicon]

Can one swop the coils from the working side/one to the side/one that blows?
This whole problem sounds like a Hydraulic back pressure making the spool get stuck - Hand this one to the mechanical team. Let them relieve the pressure and prove the circuit.
You have already proved the 4 times over current and the fact that the electric system works.