koyo plc 260 cpu disconnecting power off

[ALT]

Dear ALL,

I have D2 -260 cpu of koyo with exapanded module(D2-EM) and the power supply of D2-06bdc-1 and D2-09bdc-1 for the 2DI,2DO,3 RTD and 3 AI&AO modules with 10 baseT(H2-Ecom).This plc system was running properly without any issue suddendly from yesterday the Plc power is getting off while running and the whole system is getting trip.

What are the chances of PLC power getting off as the PLC is powered by the DC batteries of 24V with charger.in system errors i have seen the "E250 I/O bus failure ".

Can anybody can tell tell what could be the reason of PLC getting powered off while running.


Thanks

 

[bce123]

Is your plc power and your i/o power seperate?

 

[ALT]

Power source is same for the plc and i/o distributed from the batteries.i faced this problem thrice and after restarting the power the plc is functioning properly and suddenly sometimes plc power LED is going off.

 

[bce123]

When the powerlight is off check voltage to se if voltage is being pulled down by field devices it is best to have seperate power supplies for the cpu and field i/o

 

[ALT]

when the power led was off i have checked it and was showing 24 v and as i dont have much field devices only some 20 analog inputs and some 10 relay outputs to contactor coils.as the system was running from last one year suddenly this problem started

 

[ALT]

what are the list of causes for the plc power led to go off has anybody faced this problem

 

[keithkyll]

1) Intermittent connection at batteries. Use meter in Min/Max mode and leave it attached until the fault.
2) The power supply is bad. Replace the base/power supply.

 

[ALT]

what is the min and max voltage that plc gets cutoff.sometimes the batteries are giving 27 v instead of 24 v to the plc will it be the problem for plc.

 

[keithkyll]

" 10.2 – 28.8VDC (24VDC) with less than 10% ripple ".
From page 2-8 of DL205 Users Manual

 

[ALT]

Has anybody faced this problem earlier.How can i diagnose this issue of plc power shutting while running.

 

[ALT]

what are the reasons for plc power going off by-itself any voltage ranges for plc .plc power getting trip where can i find the voltage ranges and reasons for plc power getting off.

Thanks

 

[icky812]

As a FYI, this has been asked over at the AutomationDirect.com forums as well.

 

[keithkyll]

I already told you the voltage range in post #9. I see from your posts at Automation Direct that you have an expansion rack, and both supplies are shutting down. It's unfortunate you didn't provide that important clue here.
The most likely cause is spikes on the supply input. I suspect supplies are latching in shutdown. Power cycle needed to reset. There is a multitude of Switch Mode Power Supply (SMPS) designs, so it's hard to say for sure.
Check your battery connections. Intermittents might appear as spikes, or the intermittent might be causing your battery charging supply to spike.
Add a 100 MFD, 50 volt, low ESR capacitor (Panasonic FC series) and .1 MFD Monolythic ceramic cap to the input side of each supply. If that works, then use a storage scope or line analyzer to monitor spikes and find cause.

 

[ALT]

Sorry Mr Keithkyll.i have missed that expansion module here in hurry and posted the same thread in AD also as i am seriously struck with this problem so finding various ways to get the solution.Can we see any logs in plc,the disturbances in power.

As in our circuit DC to Dc converter is not there i am looking for it in market after getting i will add it.

how can i isolate the data signals coming from contactors to PLC with the PLC power source as it may have surges.The suggestion u have given to check with some capacitors,right now i could't do that as i dont have that items it will take some to get it.Please provide any thing else to solve this issue.