I finally am installing the outdoor sensor for my Trinity boiler to take advantage of energy saving features.
The outdoor location (northern/coldest) is about 40 feet from boiler.
Sensor is 5 volts.
What size wire should be used? bell wire?
Thanks,
Mike
Trust in God, but row away from the rocks.
Replies
Bell wire should be fine. The current flow is negligible.
No electrons were harmed in the making of this post.
So I figured, thank you. Mike
Trust in God, but row away from the rocks.
Many a weather compensator has been fooled by electrical interference picked up along a sensor wire...save your self a whole lot of trouble and purchase 3 wire shielded cable.
RBean
web: http://www.healthyheating.com
blog: http://wonderfulwombs.typepad.com
Twisted pair should be all that's needed -- shielding won't really do any good. Avoid jacketed thermostat wire that has no twist. Usually bell wire has a decent twist, Cat 3/5/6 data cable would be better.If ignorance is bliss why aren't more people
happy?
Having used both twisted pair and shielded cable ... I've had better performance (less challeneges) with the cable...just my experiance. Granted every job has its own unique characteristics...heading out to a job to locate a signal error ranks right up there with finding coins plugging up the inside a heat exchanger...
"Do not run the wires parallel to telephone or power cables. If the sensor wires are located in an area with strong sources of electromagnetic interference (EMI), shielded cable or twisted pair should be used or the wires can be run in a grounded metal conduit."
Six of one, 1/2 doz...perhaps.
Cheers,
RBean
web: http://www.healthyheating.com
blog: http://wonderfulwombs.typepad.com
My, another controversy. I have a lot of left over cat 5, so I'll hopefully use that.
Is cat 5 shielded? The run will be well isolated from any other wires.
Thanks to all who responded. Mike
Trust in God, but row away from the rocks.
The thing is the shielded cable is generally being compared to thermostat wire, which isn't twisted.If you have cable that's shielded AND twisted, that's fine, but if it's one or the other take twisted.Cat 5 is the premium of twisted-pair cable. Be sure to use a pair (eg, red/white, white/red) to get the benefits of the cable.
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Actually, thinking on this I realized I was making a possibly bad assumption, that the electronic receiver for the sensor is designed halfway reasonably. Any engineer with a background in control systems would sense the signal with a circuit utilizing at least a crude immitation of a differential input. With such a design feature twisted pair would be all you need. Without that feature a shielded twisted-pair cable (with the shield grounded at only one end) would be needed to reasonably reject noise.
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However, one can, with Cat 5, achieve at least the effect of shielded, possibly better, by simply grounding (at one end) the unused wires.
If ignorance is bliss why aren't more people
happy?
Edited 11/13/2005 1:07 am by DanH
Edited 11/13/2005 8:51 am by DanH
Trust me, shielded works. Try getting into the middle of a pissing match between controls, owner, and manufacturer, and the solution is now 2000 dollars and all that was saved was pennies per foot.