Chromatography Forum

Hello everyone,

We are using a thermo accela system with a 600 series pump. We have been experiencing a problem that has steadily gotten worse. The error that occurs is "solenoid error". It occurs in middle of gradient during runs. This error used to occur once every few hundred injections. Recently it started occurring much more frequently to the point where it is occurring pretty much every injection.

According to the pump manual the cause of this error is: "A proportioning valve’s solenoid is disconnected or defective.Physical problem with the hardware or connectors: Contact an authorized dealer."

Indeed if you unplug the proportioning valves wire in the middle of a run it will shut off the pump and say "solenoid error". So I think the problem might be the proportioning valves cable assembly is worn out. If you look at the wires which connect to the proportioning valve there is a coating which appears frayed. I've tried cleaning this off and checking the pins to make sure they are connecting but nothing is making a difference.

I wonder if I have to just replace all the wires or could it be another problem? Has anyone experienced this?

Edit: spoke with Thermo rep. Appears that the proportioning valves and cables will need to be replaced. Will report if this works.

As a temporary fix switched to valves C and D (normally use valves A and B). Solenoid error became less but still occurring every 20 or so injections. Odd that all the valves would break at the same time or no?

This is the strangest error. It went away for about 2 weeks and then returned again. Nothing has changed. I no longer believe that the problem is the proportioning valves because if that is so the error should constantly be occurring.

Up front: I've not used this system.

From what you're describing, could the valve controller be the issue? Faulty connections or dying control ports?

JeffeTw:

Yes I do think it could be control parts or faulty connections. The problem could be the pumps control board or the proportioning valves and their wires / connections. Since I can't isolate the problem to a specific proportioning valves its either replace all of them (~$5000) which might not fix the problem. Or replace the control board which you might as well replace the pump at that point. So yea no easy choices unfortunately.