The junction box is the hallmark of the installer and can tell us a lot about his or her qualifications. In this article, I will describe the top 5 mistakes that electricians when working with junction box.
1. lack of stocks
This error has different degrees of severity in different mountain professionals. Do not forget that the length of the reserve there are some, though not specific, but still the norm.
According SEP claim 7. 2.1.22 in the joints, branching and connection of veins of wires or cables must be provided for supply of wire, providing an opportunity to reconnect, tap and connection.
2. Twisting all the way
This is a very common error occurs when rasklyuchenii conductors using latching twisting or worse without it. This is where not only the twisted bare wires, but unstripped wires all the way.
This error is similar to the above the fact that we, in fact, do not leave the stock to re-connect, as the compound itself begins at the point where the wires come together at one point.
Reconnect assumes that the previous is completely bitten off and redone. And due to the fact that the conductors during the uncoiling and reverse twisting experiencing excessive mechanical stress - to guarantee their integrity after this impossible.
Therefore, the margin to be left intact of the conductors mechanically.
3. invalid connection
This error relates primarily inaccessible for maintenance boxes for suspended ceilings or inside structures of plasterboard. Since the most common violation - is the use of quick-terminals or any other releasable connections in boxes without access.
The boxes are not available should not be gasketed joints!
4. Irregularities in the cutting of cables and junction boxes designs violation
Sometimes you can find cases where the wiring takes place at all without boxes. Such compounds are also called "soaring Wiring". Such compounds are unlikely to make the electrician with experience. Yet for such errors is to remember.
But the violation of the integrity of the junction box - a very common phenomenon. For example, missing seals at junction boxes - you can even be found in the portfolio of the famous electricians.
5. Insulation
In terms of isolation there are 2 major types of compounds. The first type - are all possible terminals, who already have in their construction housing of electrically insulating material and which does not need to be isolated further. But at the same time to use them is impossible without access boxes.
A second type of permitted connections - is any welding, brazing, crimping, which require application of additional insulation materials, but they are allowed to leave in the boxes without access.
Incidentally, the compound grounding conductor soldering recently banned (in accordance with GOST P 50571.5.54-2013 see. P. 543.3.1) !
Only do not use the mountain specialists as insulating materials: caps from markers, tape, cellophane bags, adhesive tape and so on. These are all so-called improvised materials use is forbidden!