Topic: UV/Solar extension - build a patch cord or splice new connectors?

[piconut]

I'm extending my UV and Solar Radiation sensors and I have 150 feet of direct burial CAT6.  I'm wondering what the best is way to connect up the sensors and ISS.  For those that have done this already, did you cut the ends off the Ethernet cable and spice on two RJ11 modular plugs to each end, or do you make a patch cord with a female RJ45 on one end and two RJ11 plugs coming off that (for each end of the CAT6)? I've never spliced into this direct burial cable before and not sure how to deal with the grounded portion of the cable.  Do I ground both ends or leave both ends ungrounded?


Scott

[DaleReid]

Scott:

I have extended a set using the cords Davis sells, but since you have the Cat6 already, you don't want to invest in the stuff.

I know the black UV resistant wire in the company kit is basically four or six conductor phone extension wire, the flat stuff, similar to what is on the sensors already.  The kit uses a butt connector that the RJ series plug plugs into, on each end.

I asked earlier and started a thread on how long one can extend and if there is anything magical about the wire, that is does the sensor have a constant current or a voltage output.  I recollect that anything up to about 150' should be OK, but there is a fudge factor due to length of run after 40-50' or so.  Look for my thread to see the well informed responses to the question, including links to Davis' spec sheets that were very nicely provided. (and printed out by me but at another location).

The Cat cables use twisted pair, etc.  I guess one could trial using those nice crimp phone wire connectors that do a quick and waterproof piercing of the cable and see what you get, running it in test mode for a few days to see if the readings behave themselves.

I think you could do both the sensors on the same cable since you have all those pairs.

I know you can attach RJ plugs onto the Cat6, and since there is no problem with capacitance or even grounding concerns, you should be able to let each end float and plug into a butt connector with a wee bit of dielectric grease on the fingers and a tight wrap with self annealing tape or even a layer of elephant snot over it to keep the moisture out, especially at the upper end.  The lower end will just plug into the ISS.

But I defer to the experts who have already done this.... my sensors still are in the winter shade in the afternoon, with many weeks of subzero temps and now just yesterday a monster snow storm keeping me off the tower and doing the final install of my sensors to their new home.

How you mounting the sensors remotely?  Did you figure out some what to use the little tray that they originally came on?

[piconut]

How you mounting the sensors remotely?  Did you figure out some what to use the little tray that they originally came on?

I'm mounting the sensors on the anemometer mast on the roof and I plan on using some slotted angle iron to mount the sensors.  I'll probably just use the stock Davis mounting plate (tray) and bolt it to the slotted angle iron.  I haven't removed the Davis sensor tray as it is currently mounted to my ISS mast but I'm assuming that it won't be difficult to remove and reuse with the angle iron.

[C5250]

Do I ground both ends or leave both ends ungrounded?

If practical, ground one end.

The only meaningful difference between CAT6 and the Davis cables is the conductor twist and the shielding that CAT6 has. Both can help to reduce induced noise. The shielding will be more effective if it is grounded (grounding both ends may create a ground loop that could increase noise unless you know for a fact that both ends are at the same ground potential). The published Davis specs for the cable length effects will still apply as the voltage drop issues of the longer cable will still apply.

[Ian.]

I have just done a very similar thing using Cat 5 cable to extend the two sensors about 40', I crimped rj11 at the ISS end and in the loft terminated the other end in a dual gang rj11wall plate.

The sensors were mounted on an existing antenna, and I used a rj11 extension lead from the sensors to the wall plate, it seems a bit convoluted, but it works just fine.

[piconut]

Are the connections to each sensor just two wires?  Also, what positions do I put the wires in on the RJ11 plugs?

[Ian.]

Hi,

For ease, I replicated the ISS socket wiring remotely, originally I did not have enough cores left in a cable which was installed and looked at sharing power and one leg of data return across cores, although it was more work, I opted to run in a new 4 pair cable to remove any future problems.

So, I used 2 pairs for the Solar and 2 pairs for the UV, the attached drawing shows the colour and position of the wires from the ISS socket through the plug and out again to the wall plate.

The wire colours on the back of the rj11 faceplate match those of the sensors making the job even easier, I used an extension cable from the faceplate to the sensors making removal for maintenance easier than cabling directly to the sensors in my case, the one's I chose were a pre-formed male to female, connector, rather than the other version which is a male to male then uses a coupler to convert to female.