Navigation

Power Supply 24VDC in cpu problem

Created by: autom at: 3/6/2010 12:17 PM (3 Replies)

Rating (0)

Thanks 0

4 Entries

3/6/2010 12:17 PM	Rate (0)
autom Posts: 89 Rating: (1)	Hello to everyone. In a factory there is a sitop power supply 5A. the 24VDC goes at the rack which has the cpu, in 2 touch panels and in 5 valves which need 24VDC. In no specific time all the modulles that need 24VDC is down. The cpu, the panels and the valves switch off. I meassured the voltage at the input of power supply and is 230VAC. The same thing happened and wheni cut the power fromall the panel. When the power is restored the 230VAC goes to thesitop power supply 5A but everythingthatneeds 24VDC is off. ALSO when this thing happensthesitop power supply make an annoying noise. But when i switch off thesitop power supply and switch on it again everything works fine. I thing the sitop power supply need to be changed. But my friends do you have any other ideas why that happens? Also the factory has common ground and neutral, is that problem? Thang you all for your time
autom Posts: 89 Rating: (1)
Suggestion To thank Quote Answer

3/7/2010 9:53 AM	Rate (0)
Ayman Elotaify Platinum Expert Joined: 5/28/2008 Last visit: 10/7/2024 Posts: 4515 Rating: (839)	Dear autom, I am not sure about your configuration, but from my experience, this problem may happens if you have an under/ overvoltage relay or what we called power monitoring relay connected to the mains and if you connected the contact of that relay in series with the 24VDC output of your power supply. In this case and if any violation happen in the mains, the 24VDC comes from power supply will not be fed to the load ( whis is here valves, modules and the touch panels). And in most of these relays when the violation happens, you should either to acknolage the fault by a button exist on the power monitoring relay itself or you have to cut the power from the relay which you have did already when cutting the power on the whole panel. Hope this helps.
	Last edited by: Ayman Elotaify at: 3/7/2010 9:53 AM Ayman Elotaify
Suggestion To thank Quote Answer

3/7/2010 10:50 AM

Rate (0)

autom

Posts: 89

Rating:

(1)

Dear Ayman,

First of all thang you very much for your reply.

As i saw the panel they dont have any relay in series with the 24VDC output of power supply. But i will look itthe next time more carefully and i will change the sitop 5A with a new one.

Thang you a lot.

3/9/2010 1:46 PM	Rate (0)
Raednabeel Posts: 96 Rating: (7)	Dear, Are you sure that 5A is enough for all devices even if all of them works at the same time ? BR
Raednabeel Posts: 96 Rating: (7)
Suggestion To thank Quote Answer

Share this page:

Share this page on...

Created by: autom at: 3/6/2010 12:17 PM (3 Replies)

Rating (0) Thanks 0

4 Entries

Last edited by: Ayman Elotaify at: 3/7/2010 9:53 AM

4 Entries

All about SIMATIC S7-300 / S7-300F

Follow us on

Rating (0)

Thanks 0