[RE-wrenches] Polaris gone bad?

[Drake]

At 01:35 PM 4/6/2017, you wrote:
>Recently we interfaced with another solar install firm that has gone 
>back to wire nuts due to this same problem.


Wire nuts have the advantage of holding the wires tight with a 
spring. The spring follows the cold flow of the copper over the 
years. A screw type connection does not.

When I service an old breaker box, usually the wires are loose under 
the screw connections, especially on the neutral and grounding bars. 
Often they are very loose, and I bet that the screws were tight after 
the initial installation of the equipment.

On old industrial control equipment, I've learned the hard way to 
tighten all screws before doing anything in the box, as wires are 
prone to fall out of the loose screw connections. Again, these 
connections have the weakness of being held by terminal screws, with 
no spring to follow the cold flow of the metal.

With wire nuts, it can be a bit tricky to know if you have a good 
connection, as the connection is hidden under the plastic cap. It is 
good to pull hard on each wire separately to be sure it is securely 
under the spring. It is crucial never to mix copper and aluminum 
under a wire nut unless it is one specifically designed for the 
purpose. Unless specifically listed, all out door wire nuts should be 
in a weather proof box, and preferably taped.

Drake Chamberlin
Athens Electric LLC
OH License 44810
CO License 3773
NABCEP Certified Solar PV
740-448-7328
<http://athens-electric.com/>http://athens-electric.com/


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20170408/7e0a263a/attachment-0003.html>