Corrosion in RJ11 / RJ45 Connectors

Have a question or want to start a discussion? Post it! No Registration Necessary.  Now with pictures!

Threaded View

Has anyone encountered corrosion in RJ11 / RJ45 jack / plugs? I think
this effect might be mostly limted to areas closer to the sea, high
humidity areas, in higher temperature areas and where there might be
additional airborne pollutants. Florida and Hawaii come to mind.

Also, the use of voice on the line (with voltages of up to +/- 48 volts
- ?) may worsen electrolytic corrosion - I don't think it's a galvanic
corrision effect. Not sure.

I'm wondering what will happen with the planned Power over the
Ethernet. That will use 48 volts across pins of the RJ45 connectors.

Thanks for any comments you may have,


Bob Elliot

Re: Corrosion in RJ11 / RJ45 Connectors


we used to make NTU's for Irish Telecom. Corrosion was a challenge.

You can cover the contact surface with a very thin layer of wax or seal the
jack's arperture with a jelly.


Quoted text here. Click to load it

Re: Corrosion in RJ11 / RJ45 Connectors wrote:

Quoted text here. Click to load it

On it's own, gold doesn't corrode.  However, some connectors might be a bit
cheap with the gold.
Quoted text here. Click to load it

It's not the voltage that causes that, it's the current that caused the ion
migration.  Also, higher voltages tend to penetrate the corrosion.  I
believe the phone companies refer to that as "sealing current".

Re: Corrosion in RJ11 / RJ45 Connectors

James Knott wrote:
Quoted text here. Click to load it
As often before your chances off success is better with a quality system.

I only remember a few cases across the thousands of quality connectors I
have installed and serviced.
All of them could be linked to cleaning or other physical contamination

The Cabling Guy
I only express my own personal opinion on Usenet.

Re: Corrosion in RJ11 / RJ45 Connectors

"" wrote:

Quoted text here. Click to load it

    Seen it in wet locations. Kitchens, laundry rooms, wet basements
and the like.  The wiping action of plugging it in usually scrapes enough
of the corrosion off to make a connection.   Of course ones that are
gold plated too a sufficient thickness are not going to corrode.  Don't
buy cheap connectors for these locations.  Usually the problem with
these connectors are the corrosion inside on the copper wires has
caused problems.  You can get various compounds for sealing these
in your local auto parts store. Look under the battery connector
sealing sprays.


Re: Corrosion in RJ11 / RJ45 Connectors wrote:

Quoted text here. Click to load it

Does not have to be Florida or Hawaii: in one instance here in PA all it
took was a cleaning lady, who decided the faceplate is dirty. We could not
identify the actual solution she used, but the RJ11 plug got totally
destroyed. Upon taking it from the jack all the contact material simply
fell down in a form of a black powder. That effectively knocked off a
digital PBX phone that uses constant 48V (as oppose to "smart" 48V of PoE
that you’ve mentioned here). Much less of a contact problem would render
PoE circuit dead because before applying the full power an 802.3af power
hub/switch sends a weak-current polling signal and looks for a response
from the terminal equipment.

Dmitri Abaimov, RCDD">
Cabling Forum, color codes, pinouts and other useful resources for
premises cabling users and pros">
Residential Cabling Guide


Article posted with Newsgroup Archive">

no-spam read and post WWW interface to your favorite newsgroup -

comp.dcom.cabling - 1622 messages and counting!


Re: Corrosion in RJ11 / RJ45 Connectors

Quoted text here. Click to load it

You shouldn't allow your connectors to get wet.

I have a problem with 66 block corrosion, caused mostly, I believe, from
condensation.  The room also has a custodian sink and washer and dryer
in it.

I had a problem with corrosion in a classroom.  It's the chemistry lab.
You know that the jacks and plugs have gold plating, which protects them
against corrosion.  Well, it takes a lot to corrode gold.  I guess the
chemicals in that lab must have been vapors from both nitric and
hydrochloric acids, which make aqua regia, IIRC.  The chairs were up on
the desks, and I noticed that the chairs' chrome legs were corroded
badly, mostly brown rust.

Quoted text here. Click to load it

That's already being used.  Without problems.

Our digital PBX uses 54V (which is what 48V batteries put out) at up to
150mA.  We don't have any problems at all with power over 66 blocks, 110
blocks, RJ-11 or RJ-45.  The telcos use 108V across the pair with T1

Quoted text here. Click to load it

Site Timeline