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MC4x/XC4x 12V 30W solenoid overload error
Dániel Novák 1 month ago
in Master modules / MC4x
•
updated by Gustav Widén (System support) 2 weeks ago •
3
What is the suggested solution for driving NG6 valves with standard 30W solenoids at 12V system voltage with MC4x/XC4x modules?
We use the HS+LS digital outputs for driving Parker D1VW valves with "K" code solenoids in a 12V system. As stated in the instrucion book, max load per output is 2.5A, but the measured current is 2.7A (as in the D1VW catalogue). The measured solenoid resistance is 5 Ohm, but it should be within 7-14 Ohm (MC4x/XC4x instrucion book).
30W solenoids are standard at other valve suppliers too, so changing the valve isn't an option. Change the system voltage to 24V also isn't possible for this project.
Customer support service by UserEcho
A suggestion for staying within specification is to use a Digital out HS instead.
The MC4x/XC4x digital out HS is rated to 4 A.
As you mention overload error in the title, did you test and see overload status on the Digital out HS+LS?
In that case, was it when the DOUT was on or when deactivating the DOUT?
With say 14 V supply and a load that is 5 ohm when it is cold, you should still be below the overload error detection threshold for when the DOUT is ON.
The resistance values that the instruction books list are not really the max load, these values are for max allowable load inductance without external clamping diode.
are
Hello Gustav,
Thank you for your answer.
We get the overload error when activating the DOUT, and at temperatures up to ~25°C. As the error appears, the output shut off. Above 30°C external temperature there was no problem.
Because we have 18 DOUTs for an MC43FS, DOUT HS was not an option (and also for security reasons).
We tested a solution, and it seems to work: we take out the diodes and use COUTs instead of HS+LS DOUTs.
So now we stay within the limits. (We have to arrange the outputs also, so that adjacent COUT channels doesn't work in the same time).
The output is 0mA(OFF)/2500mA(ON), without any slope. We set the PWM frequency to 500Hz.
Do you suggest anything regarding to this solution (other PWM frequency?)
Do you see any risk using this in long term?
Thank you in advance.
The solution with COUT:s is good, this regulates the current.
A problem one might see with low resistance loads on COUTs is overload from a high peak current, the inductance of the coil and a higher PWM frequency prevents this. So keep the 500 Hz.
What you might experience is status saturation on the COUT, if it can't get to 2500 mA when the coil heats up.