corrosion

wolram

Can anyone tell of an additive that can be used in cleaning water
and detergent, that will help prevent corrosion of electrical connections
contacts etc, this may seem a strange question, as the obvious
thing to do is not get them wet in the first case, but this impractical
as the cost in hermetically sealing the same would be prohibitive.
all these contacts, connections are already in high ip rated enclosures
but the water still gets in.

Gokul43201

Oil.....???

Bystander

You could use gold plated connectors --- long as there aren't too many halides running around in the water --- or cyanide --- or other nasties.

Ivan Seeking

Can you tell me a little more about this application? I deal with this sort of thing frequently.

A few intial thoughts that cover most situations:

Apply white [electronics] grease on all connections. This usually protects the contacts with an occasional re-application.

What is the enclosure rating? There are quite a few ratings for water exposure. Some are only for drip, others are for submersion in up to 100 feet of water or more. I have seen high voltage plugs good to 1000 feet of water.

High absorbtion materials - silicate gel packs - are often used to handle fairly minor moisture problems. These can absorb a tremendous amount of water for the weight.

Install an indirect drain tube on the enclosure - a double elbow allows water to drain but no direct blast can get in.

wolram

by Ivan Seeking
Can you tell me a little more about this application? I deal with this sort of thing frequently.
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thanks for reply ivan, I have been unable to use the net for a while so sorry for long
delay.
All enclosures are ip 67 with little chance of increasing due to cost, nearly all are
inside mach guards, so water cannot sprayed onto them directly, all the cable
entry points are from below via cable glands.
the plant is washed every night with normal tap pressure water, diluted detergent is applied seperatly from a bucket.
All the enclosuer door seal are in good condition, so it amazes me how much water
gets into them.

Ivan Seeking

Then I see these as your best options; depending on cost and what you can spend of course:

Put a silicate gel pack in each affected enclosure. Of course you might try one or a few and see how long they last.

Check with the enclosure manufacturer for any upgrade kits for better waterproofing. A simple, inexpensive seal change might solve the problem. Some mnfctrs offer this I think; at least some once did.

Use liberal quantities of white electrical grease on all exposed connections. Make sure that this has the high dielectric value and is rated for use on high voltage electrical.

You might consider putting a 3/16 drain hose on each enclosure. When combined with white grease and gel packs should this prevent any damage.

Could the problem be due to condensation and not leakage? Do the enclosures experience radical temperature fluxuations from day to night?

wolram

Thanks, Ivan.
as this plant is for fresh food we can not use any lubricant that is not "food safe",
i did find a aerosol spray that fit the requirements for low voltage 24v equipment,
but it corroded, I have even had to replace cables that had corroded below the
insulation for a good six inches.
So without going to hermetically sealed cabinets, i thought an additive in the water
may be possible, and that it would neutralise any chemical attack..

Ivan Seeking

There is food grade white grease. I will try to find a source.

Ivan Seeking

If you can find such a thing...I would expect that your solution would neutralize the detergent action as well. Detergents are a base; this is why they work. Still, I have only had a year of chemistry so I don't mean to sound authoritative on the subject.

Edit: What are they using that is so corrosive? I have worked in chicken processing plants that don't have this problem; nothing worse for sterilization problems - Listeria! Is there any chance of using a less corrosive agent?

Ivan Seeking

Here are a couple of sources to consider. I really think something like this is your best option; unless the criteria can be changed.

http://www.mscdirect.com/PDF.process?pdf=2631

http://www.mscdirect.com/PDF/PDF04/2641.pdf

wolram

Thanks Ivan.
The di-electric grease sounds perrrrfect for my predicament, i will get
some on order pronto, by the by, i wont take all the glory for reduced
down time, i will mention your name and PFs.

Ivan Seeking

Great! I hope it works and makes you look good.

Note that several compounds are available. You also might try contacting CRC [the manufacturer] directly. Tell them exactly what chemicals you are using and they might be able to suggest a best option.

Hey, did you ever find those spark plugs? If you ever get a chance I would love to see a picture of them.

wolram

Still looking Ivan, ive just come across two tins of Prats motor
oil and spare plugs for a Levice we have recently sold, so i
must be getting close.