SLC 5/04 DH+ Preventitive maintenance ideas?

We have apporximitly 12 - 5/04s on DH+ and some on DH-485.

Other than replacing the batteries every year and checking for loose terminals, what kind of preventitive maintence should be done?

The reason I ask is because we had a blue hose fail that shut the plant down for 2 shifts and was finally trace to 1 of the blue hoses that was in a daisey chain of 6 PV+s and 5 - 5/04s. We bypassed the the blue hose in the conduit to get it going and wont be able to pull the hose out of the conduit untill Thursday.

Is there a way to check the integrity of our DH+ with a meter?

Thanks for any info is greatly appreciated.

bright676 said:

Is there a way to check the integrity of our DH+ with a meter?

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What happen to your wire?, I dont think it will ever just 'wear out' unless vibration and something sharp in your wireway, I have never heard of it going bad, that said you could ohm it out and keep a log of your finds then compare them, you could also use a megger or a hipot tester (((make sure you discount EVERYTHING before using one))) you will smoke node on the network if they are not discounted.

I have never heard of a wire just wearing out either. I wont be able to pull the blue hose out till Thursday. I just dont know, thought maybe one of the wires had pulled out of the connector, but we lost data going to 5 PVP+s and bypassing that one hose worked.

I think I would just file that one in the back of your memory... hopefully someone did not put a junction in the run, please let us know once you find out what the issue was.

To be honest there is probably little other maintenance you can do apart from ensuring terminals are tight, dust has not clogged air ventilation, things are not running to hot and all cards are located correctly. One word of warning removing & re- inserting cards seems like a good idea but in my experience it sometimes is best left alone, I have had a couple of problems where things went badly, one was I borrowed a card out of one system to try in another, great it was a quick check the card was faulty, however when I put the card back due to it's age it would not make contact with the back plane so not only needed a new card for the faulty system but had to replace the rack on the one that was working. Moral: if it ain't broke leave it alone.

Heat or vibrations can degrade a cable or the connectors.
So check if the cable is not exposed to heat or vibrations over its run.

Other things that could have caused the cable to suddenly fail:
New noise source introduced.
Existing earthing or equipotential bonding has been removed.

As to preventive maintenance:
Measure earth currents and check if the value increses over time.
Use an oscilloscope to measure signal vaweform. Check if noise or reflections change to the worse.

And if somethings fails inexplicably, ask what has changed.

Wire can wick moisture over time and eventually that will cause the resistance value to change. This typically only becomes noticeable in high humidity environments and in most applications won't present a problem (I.E. the wire outlasts the application) but when you are dealing with wire that has very specific properties, like Blue Hose, it can be more sensitive to this type of issue.