Lotem 400V compressor problem

R

razvan

Active member
Hi guys,

I'm back with a new challenge. The compressor of my Lotem 400V is working randomly since yesterday. I noticed that it starts when starting to burn the plate, but at some point (12%, 19% or 27% of the plate - this are just examples, it never repeats at the same point) it stops, then burns the plate without compressor, then it starts again (48%, 67%, 74% or so - again randomly) to end at some point again (87%, 93% or 96%). Any ideea what may cause this trouble?

Thanks,
Razvan
 
Hi Razvan,

You are still working hard?
What do you mean by the compressor? Do you mean the internal Vacuum pump?
 
Hi PACH, still working hard towards harder, as for now we are installing a SM10P and i'm sure i'll have some hard times in the months to follow.
And yes, it's the internal vacuum pump. I just call it compressor :). Any ideea on that? I see it's working and the plates look ok, but i know that the vacuum must work all the time a plate is exposed.
 
razvan said:
Hi PACH, still working hard towards harder, as for now we are installing a SM10P and i'm sure i'll have some hard times in the months to follow.
And yes, it's the internal vacuum pump. I just call it compressor :). Any ideea on that? I see it's working and the plates look ok, but i know that the vacuum must work all the time a plate is exposed.
Click to expand...

When was it the last time that the Lotem was serviced? It could be that one or more of the blades inside the pump are worn or even broken. As you can imagine this is only a remote diagnostics.
 
It was serviced last year. In the meantime we don't have service anymore, so i have to solve this on my own. I think i should open the Lotem and check the pump. Could, by any chance, be some kind of thermal protection on the vacuum pump that is stopping it when it becames too hot? some relay that is not working right or something?
 
Not, as far as I know.
You will have to switch the Lotem off and take the back pannel off. You will need 5mm Allen key to take the back off the pump and then the blades cover. WATCH AS IT WILL BE VERY HOT. Let the pump cool down first. You can remove the blades one at a time to check. The blades should be greater than 27mm in width. Make sure you insert them the correct way.
 
i will do so and let you know after. thank you

i'm back, the blades are 38 mm width, so i guess it's not the vacuum pump. anything else that may be wrong?
 
Last edited:
Follow the cable from the pump to the Distribution box. Make sure that the Lotem is switched off.Pull the molex connector out and make sure that all the pins inside are OK. The vacuum pump is controlled by a Solid state relay in the Distribution Box ( Distribution board). Maybe there is a problem with board/relay/
 
Got this problem last year, it was the solid state relay in Power distribution box. relay will cost you about 20 euros and some soldering work, at least for me it did so.
 
Pach, i followed your steps, and the pins are ok, so i guess it's the relay. Can anyone give me some details about the relay so i can look for it?

thank you all guys for the input
 
I started the vacuum pump manually, and let it run for 15 min (that's enough to write 2 plates without interruption). It worked just fine. Tryed to write two plates after and had the same issue: at 19% vacuum stopped, restarted at 53% and so on. I'm starting to think it's not the relay, maybe some detector or something, or some pressure issue.
 
razvan said:
I started the vacuum pump manually, and let it run for 15 min (that's enough to write 2 plates without interruption). It worked just fine. Tryed to write two plates after and had the same issue: at 19% vacuum stopped, restarted at 53% and so on. I'm starting to think it's not the relay, maybe some detector or something, or some pressure issue.
Click to expand...

It still could be the Relay with the intermittent problem or actually the Power Distribution board that the relay sits on PDB.jpg. Did you run the Vacuum Pump from Hardware for 15 min without any problem? When the pump switches off, do you get any error messages?
 
razvan said:
I started the vacuum pump manually, and let it run for 15 min (that's enough to write 2 plates without interruption). It worked just fine. Tryed to write two plates after and had the same issue: at 19% vacuum stopped, restarted at 53% and so on. I'm starting to think it's not the relay, maybe some detector or something, or some pressure issue.
Click to expand...

It still could be the Relay with the intermittent problem or actually the Power Distribution board that the relay sits onView attachment 2628. Did you run the Vacuum Pump from Hardware for 15 min without any problem? When the pump switches off, do you get any error messages?
 
I run the vacuum from Hardware for 15 min without interruption, without any error messages. I'm thinking of a faulty vacuum sensor or something.
 
i found a temporary solution: i increased the vacuum pump power and it doesn't stop anymore, but its more noisy.
 
What exactly did you do? Hope that you will not damage the pump.[/QUOTE]

i rotated the knob for one quarter.
 
You must log in or register to reply here.

Similar threads

P
Dot Gain and Curves, OH MY!
Replies
2
Views
3007
VladCanada
VladCanada

PressWise

A 30-day Fix for Managed Chaos

As any print professional knows, printing can be managed chaos. Software that solves multiple problems and provides measurable and monetizable value has a direct impact on the bottom-line.

“We reduced order entry costs by about 40%.” Significant savings in a shop that turns about 500 jobs a month.

Learn how…….

   
Back
Top