Stacked lugs (mechanical)

Status
Not open for further replies.
hacim23

hacim23

Journeyman Electrician
Location
washington, DC
Occupation
Electrician
When stripping your wire for a stacked lug where one is average depth and the one behind it is twice as deep: the correct way is to have no insulation inside the lug, right? So, one wire would be stripped normal and the parallel wire would be stripped twice as much. I keep finding them stripped about the same with insulation running into the lug even though it is bare under the screw. thanks.
 
hacim23 said:
When stripping your wire for a stacked lug where one is average depth and the one behind it is twice as deep: the correct way is to have no insulation inside the lug, right? So, one wire would be stripped normal and the parallel wire would be stripped twice as much. I keep finding them stripped about the same with insulation running into the lug even though it is bare under the screw. thanks.
Click to expand...
You could also strip them the same and just not insert the bottom one the extra distance to the bottom of the hole.
That would not give "positive" insertion alignment, but if you strip it the appropriate distance and stop before the insulation enters the hole you will get a good result.

Do the instructions provide any additional clarity?
Neither the catalog page nor the dimensioned drawing address that issue. And I do not see strip gauge markings on the piece.
 
The deeper lug on the bottom only clamps on the end of the conductor so it wouldn't really matter if they were striped the same length.
 
infinity said:
The deeper lug on the bottom only clamps on the end of the conductor so it wouldn't really matter if they were striped the same length.
Click to expand...

I don't disagree but what I don't like about that is having insulation pushing against the side of the lug when they don't strip it longer.

I havent been able to find any strip guage.
 
As Smart$ implied, if there are instructions then all questions would be answered. My personal opinion is that good workmanship would mean that the insulation would be stripped just enough so that it didn't penetrate the hole of the lug, but since the electrical contact is create by the set screw, as long as the insulation isn't "pinched" another person could argue that it is not worthy of "fixing". Without manufacturers instructions #2 would be correct.
 
If the conductors are the maximum size permitted you would need to strip the insulation the full length on the deeper hole. You could do it either way for smaller conductors where the insulation would pass though the hole.
 
Why wouldn't you just cut one wire slightly shorter? Does anyone think they can get paralleled conductors that close in length that the distance between one lug and the next would matter?
 
steve66 said:
Why wouldn't you just cut one wire slightly shorter? Does anyone think they can get paralleled conductors that close in length that the distance between one lug and the next would matter?
Click to expand...


one of them is slightly shorter by the difference of the lug depths.
 
GoldDigger said:
Only if you strip the conductor in the lower hole so that it gets inserted fully into a double-depth hole.
Click to expand...

Okay well it would have to be inserted fully into the deep lug in order to be terminated properly. the original question was about wire strip gauge.
 
I teach apprentices to strip wire with an eighth to sixteenth of an inch gap of copper showing between insulation and lug's entry port. This gap is an inspection window for the inspector (or me) to verify conductor strand integrity (no nicked or damaged strands).
 
Burndy Connector Theory and Application [guide] states the following:

2.1.1.2 Insulation Removal


Conductor coverings and insulations protect the
conductor from corrosion and mechanical
damage, as well as provide electrical separation
between conductive layers and/or from external
contact. When installing a connector, the covering
must be removed completely without damaging
the underlying conductor. The exposed conductor
region must be of sufficient length to
accommodate the entire contact surface(s) of the
connector.


Depending on the type of conductor, the removal
of insulation (and reinsulation of the finished
connection) can be quite complicated. Whether
working with intricate conductors that have
multiple layers of insulating and covering
materials, or just simple jacketed cables, there
exist some basic rules for insulation removal.

1. The insulation must be removed for a
length just greater than the contact length of the
connector to be installed. In the case of
compression connections, the strip length must
include additional length to compensate for the
connector’s extrusion during crimping.

2. Regardless of the method used, the
underlying conductor must not be damaged by
cutting or nicking during the insulation removal
process. Cut or nicked strands reduce the cross
sectional area of the conductor and may result in
an eventual failure.

3. After the conductor is stripped and all
insulation is removed, follow the guidelines for
contact surface preparation and, when necessary,
oxide inhibitor application.
Click to expand...

Source: https://ecat.burndy.com/Comergent//burndy/documentation/BURNDY_Connector_Theory.pdf
 
Status
Not open for further replies.
Top