why does my hydraulic solenoid keep burning up?

Thread Starter

musclemania05

Joined Feb 21, 2016
14
I'm controlling a AC solenoid from a PLC and the solenoid keeps burning up after 12-24 hours of operation, and it'll pop my 15 amp breaker. It won't short the relay or blow the fuse from the output though. I have checked the voltage going to the solenoid and current during operation and nothing unusual shows. I get 120 to coil and it pulls in about .5 Amps. I believe its neutral because it only pops the breaker and doesn't blow the fuses? Could someone help me?
 

MaxHeadRoom

Joined Jul 18, 2013
23,371
Generally the cause is if the solenoid armature does not fully shift when energised, this is one reason why I only use DC solenoids.
In this case it could be a fault solenoid.
Max.
 

Thread Starter

musclemania05

Joined Feb 21, 2016
14
Well its already burned up the 3rd solenoid and I've made sure that they are all good by measuring the ohms to be about 10 ohms. The solenoids work for like a day then they burn up and measure about .5 ohms. I wonder if its the neutral wire or there is more watts in the circuit than that 15 amp breaker can handle?
 

shortbus

Joined Sep 30, 2009
8,719
Are you using the correct type of solenoid /valve for the circuit your trying to control? There are different types for different circuits.
 

MaxHeadRoom

Joined Jul 18, 2013
23,371
If you monitor the temperature when operating/energised it should indicate if current is excessive.
What has the neutral got to do with it?
Are you possibly exceeding the duty cycle of the valve?
Every time you energize the valve, the current is at least 10x the continuous current on a AC version.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
23,371
and yes the neutral would have factor because if the 120 VAC is going through the loop and doesn't have reference to go back then it'll overload and pop the breaker.
.
You would need to explain that further to me?o_O

Do Not put a resistor in series with the valve unless you want further problems.
If insisting on AC it may have been an idea to use a pilot spool operated valve in this case.
If you have full voltage and operating within the duty cycle there should be no problem.
Incidentally, on an AC solenoid valve, never use the manual operator when the solenoid is energized.
Max.
 

shortbus

Joined Sep 30, 2009
8,719
If insisting on AC it may have been an idea to use a pilot spool operated valve in this case.
This was my thinking in my earlier posting. Many people see a hydraulic valve and think they are all the same. And then complain when they don't pick the correct type for the hydraulic circuit they're building.
 

Thread Starter

musclemania05

Joined Feb 21, 2016
14
oh here we go with guys like this who have no hands on experience, short bus iv used this same solenoid in all my applications and never once had problem till now but what i did was interpose a relay and it brought the current down significantly and so far so good

but what i would like to know is what makes a DC better than a AC solenoid?
 
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panic mode

Joined Oct 10, 2011
1,882
my experience was to select components and construct systems correctly so they don't blow up every few hours.

nobody has time to elaborate all possible scenarios

if you need specific help, make it easy to help you by posting specifics:
* post correct link or PDF datasheet
* post YOUR circuit
 
Last edited:

oz93666

Joined Sep 7, 2010
737
There can be only one reason it "burns up" ....To Much Current !

Reduce the current to the minimum required to activate. If AC try putting a diode in series effectively halving the current , may need a capacitor across the solenoid to stop chatter.
 

MaxHeadRoom

Joined Jul 18, 2013
23,371
but what i would like to know is what makes a DC better than a AC solenoid?
If an AC solenoid does not completely shift for some reason, it will usually burn out or destroy any solid state device operating it.
Also if maintenance staff shift it manually when energized during trouble shooting, (often seen).
If it is being used correctly with the correct voltage, there should be no need for any other measure using a component to modify its behavior.
DC solenoids are becoming the norm now for a few years, N.A. has been a little behind in this trend.
Max.
 

sagor

Joined Mar 10, 2019
469
Your datasheet shows solenoids that are basically all DC. Those that are rated for AC must use: "Connection to AC voltage mains via control with rectifier" (page 2 of datasheet, part 08). That is, there is a specific controller/rectifier for use of those solenoids with AC voltages.
Based on that, you cannot connect AC directly to that device. Of course, your part number is not in that datasheet, so you may have pointed us to the wrong information.
 

shortbus

Joined Sep 30, 2009
8,719
There can be only one reason it "burns up" ....To Much Current !
There is another that can do it. Using a non servo type valve where a servo type should be used. The non servo will have to try and overcome the whole line pressure and cause the solenoid to make more heat.
 

MaxHeadRoom

Joined Jul 18, 2013
23,371
Also it would be handy to know the precise part No. as the link given shows a spool valve that is DC solenoid, if fed with AC there is a optional rectifier connection.
Several solenoids I have hooked up recently were DC/AC as there was an internal bridge rectifier offering both options for supply.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
23,371
but what i would like to know is what makes a DC better than a AC solenoid?
One point is that apart from initial power-on the DC solenoid is superior once picked up, it will stay retained for longer if there is a voltage drop.
The high initial current of a AC solenoid is its only asset, after that initial operation of the armature actuation, its performance and ability for the solenoid to remain in the energized position is less tenuous and if not kept in this position, will usually result in burn out of the coil or other disconnection.
The DC version does not suffer the same way.
Max.
 
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