ControlLogix 5555 battery replacement

Howdy,

We have a piece of equipment on the plant floor that has a ControlLogix Logix 5555 CPU and it's time to change the battery. I cannot find any information at all that tells me if this unit needs to be powered up with AC while the battery is swapped or not. I know that some of the other A-B PLCs on the floor require AC to be applied while the swap is being made and that some others have a capacitor and require you to yank the CPU to change the battery that's parked out back. Does anyone know for sure on the Logix 5555 unit what the procedure for swapping batteries is?

Thanks a bunch!
Mike

If you can access the battery without pulling the module i would change it with AC on, otherwise you may loose the configuration. Either way, backup the program first.
Roy

Roy Matson said:

If you can access the battery without pulling the module i would change it with AC on, otherwise you may loose the configuration. Either way, backup the program first.
Roy

Click to expand...

Hi Roy,

Thanks for the reply. I'm of the same mind as you on this one - so far all of the A-B units that you can access the battery from the front while the unit is in production require the AC to be applied during the battery swap, so....

Backups? Hey, I've been bitten by that one already, but thanks for the reminder.

Take care and thanks again,
Mike

As long as your code does not have any adverse code - i.e. stop process if the battery goes down (don't know why you would, but thought I would mention it anyway) you can change it while the processor is running.

If AC is not supplied, then removing the battery will erase the program from the processor. But then again, with the 5555 series battery issues, if you don't have AC supplied for a short time then the battery will drain.

To summarize - change the battery online. We do it all the time.

I have been on impression that battery is to keep volatile memory when external electrical power is not supplied. So if you change battery, change it always with external electrical power supplied.

If someone has seem procedure to do otherwise, please post link to manual (or something else) stating why and for what to do so.

It seems to be rattling around among the rocks in the back of my head that there is a capacitor that will hold the program long enough ( not very ) to change the battery?

realolman said:

It seems to be rattling around among the rocks in the back of my head that there is a capacitor that will hold the program long enough ( not very ) to change the battery?

Click to expand...

usually what happens is if you need the processor to hold the program a few seconds it wont. but if you go to try and clear the program it takes 10 minutes.

realolman you are correct with the SLC 5/03, 5/04 and 5/05. But the CLX does not have the capacitor.

The SLC needed a cap since the processor had to be removed from the chassis to replace the battery. The CLX has the battery right on the front and does not require removal to replace the battery.

So Michael, follow what Oakley said.

OG

Hi again,

Thanks to EVERYONE for their help on this.

I'm going to leave the AC on the unit for the battery swap as suggested. I looked high and low for the procedure at the manufacturer's sites and came up empty-handed.... and I don't like guessing with high dollar equipment on the floor.



Thanks again!!
Mike