[rotccapt]

Hi all,

I am in the process of upgrading my small 1ft by 2ft desktop router to a 2ft by 4ft router. My original machine was powered by a home made power supply that used a 24v transformer, bridge rectifier and a large cap. I decided to use a commercially available power supply on my new machine chose the Mean Well LRS-350-24. I have two of these supplies, one is powering the machine, and the other is powering my spindle motor. I have been running the spindle for a while with no issues. Today I got my new machine up and running with the new power supply.

The problem I am having is that when switching on the machine it will run for about 5 min then the power supply will appear to cycle off then back on, but it will only supply around 12 volts instead of the rated 24v. After duplicating the problem several times, I switched over to my second power supply, that has been running fine on the spindle, and am having the same exact problem. I know I am not pulling more than 10A on the machine, because that is what my old home built supply was rated at and i am using all the same components. The Mean Well is rated at 14A.

My build consists of: Hobbycnc EZ board, 2ea Nema 23-305 and 1ea Nema 23-425 stepper motors operating in unipolar config. I am using belts on the X and Y and a lead screw on my Z. I ran 18awg shielded cable for all motors with an average run of about 12 feet. I am using Linux cnc for control software

During the config stage of Linux cnc I had the machine running for almost an hour while getting the speed and acceleration set with no problems. The power cycle will happen regardless of what the machine is doing, I have had it happen while sitting still as well as moving all axis at the same time. I have not ran a program yet. If i turn off the machine and turn it back on everything operates as advertised and starts the cycle all over again. I'm about to go back to my original power supply if i cant figure this problem out. If anyone has any ideas, troubleshooting processes, or other information, I would be grateful.

Thank you for any help.

[Tweakie]

I know I am not pulling more than 10A on the machine, because that is what my old home built supply was rated at and i am using all the same components.

It sounds like over-current to me so just to be sure I think you should measure the current that is being drawn with a suitable meter. (To measure more than 10Amps you may need to use a meter + shunt - Google electrical shunt).

Tweakie.

[rotccapt]

i have a suitable amp meter from my rc airplanes. ill plug it in and see what it does and report back.

[rotccapt]

ok, plunged in my amp meter. i was reading 29v and 2.1A with the machine sitting there. so i adjusted the voltage pot down to exactly 24v and amps stayed the same. the max i could get for amps was about 4A with all three axis moving at jog speed. during the power cycle amps dropped off to 0.7-1 amps voltage stayed the same. the only other symptom i was seeing was that my led cooling fans stopped working and would only dimly light the leds. Also the power led on my relay board was about half the brightness that it usually was. after turning off the machine power i was only able to get the machine to run a homing sequence before the power cycle happens again and could not get it to stay on long enough to do any rapid moves

im starting to suspect driver board problems not power supply, the power led on the power supply stays on during the cycle. also after the cycle the test points on my board that you can read for adjusting current start out at 0.4 v with means it is adjusted for 3A before the power cycle after it is reading 0.3v also the 28v fan output is reading 5v after the cycle.

[rotccapt]

i have confirmed that this is a driver board problem not a power supply. i switched back to my original power supply and have the same problem.