Acidic Environment Recommendation on AB PLC

Hi guys,

We have a client with an acidic environment. They currently have a lot of relay logic but want to convert to PLC control. I have seen some of their current control panels and they have corroded badly. I was wondering what recommendations would you have for PLCs, relays that will not corrode or corrode slowly overtime? They would like controllogix or compactlogix type PLC

Thanks,

N2 or CDA purge inside panel. Just enough to maintain positive pressure.
Non-metal enclosure. NEMA 4X

+1,

Before ordering any enclosure, you must find out what acids are present and look at the manufacturing compatibility chart.
do you want stainless tell 308 or 416 or a special order.

james

Worked three years in a battery plant. Most of the cabinets were 4X some were 6P. And the Acid was sulfuric ( 52% ) before mixing, 6,12, and 18% post.

If the cabinet stays closed....all the way.....all toggles turned and completely engaged then whatever is floating in the air won't do any real harm. What you have to take care of are the HMI's they will degrade and suffer the most from exposure. Operators were always touching them without removing their gloves. The mylar wore down quickly. Lot's of Companies will rework the panels. If you have volume as we did, you can work out a cost effective deal with them.

But as far as the PLC's ( micro 1400's ( about thirty of them )) never noticed any real degradation. The plant had been in operation about six years prior to my arrival.

Plant hygiene is important also. A good wash down every three or four days doesn't hurt either.

Good Luck

Not sure of availability on compact-logix or control-logix, but we also have highly corrosive/conductive environmental dusts, and typically order in conformal-coated Micro-Logix PLCs for those areas. Lead time for them is significantly longer.

dburnum,

"and typically order in conformal-coated Micro-Logix PLCs for those areas. Lead time for them is significantly longer."

What is conformal-coated plcs?
what is their part number?

regards,
james

James Mcquade said:

dburnum,

What is conformal-coated plcs?
what is their part number?

regards,
james

Click to expand...

Looking at an 1100 sitting on my desk, it doesn't appear to have any change on the product label, other than a factory sticker applied "CONFORMALLY COATED". My supplier is well aware of issues we have in our plant, and informed us a few years ago, that AB has since decided to start coating electronics on the Powerflex 52x series and 75x series drives, and on certain PLCs and drives by request. All it is, is some sort of clear lacquer that is applied over the electronics to protect them. We had issues with coiled inductors of the bridge rectifier on our drives blowing apart when conductive dusts got into them. Even our 4x rated Powerflex Drives get some dust into them over time. We decided to start having everything coated for reliability.

Since going that route, we have little to no issues.

Regards,
Douglas