Figure 5-32.Portable cord splices.
Large stranded cables (fig. 5-33) are not often used
in residential wiring; however, they are used in other
situations. such as for battery jumper cables and
welding cables. When jumper cables or welding cables
are broken, they can be temporarily repaired, as shown
in figure 5-33.
Because solderless connectors (such as plastic end
caps) are time-saving and easy to use. the electrician no
longer needs to solder each and every splice. It not only
takes less time to make a solderless connection but also
requires less skill. However. soldering is still the most
reliable method of joining pieces of wire, and every
electrician should learn how to solder.
Once the decision is made to solder an electrical
splice and the insulation has been stripped off the wire,
the splice should be soldered as soon as possible. The
longer the splice is exposed to dirt and air. the more
oxidation will occur thus lessening the chance of a good
solder joint. Clean metal surfaces. free from oil. dirt. and
rust (oxidation) are necessary to allow the melted solder
to flow freely around the splice. The surfaces may be
cleaned by using light sandpaper or an emery cloth or by
applying flux to the joint as it is heated
Figure 5-33.Gable splices.
Solder usually comes in either bar or wire form and is
melted with heat from soldering devices. such as a
soldering iron. soldering gun. or propane torch (fig. 5-34).
The electric soldering iron and soldering gun are
used when electrical service is available. The propane
torch is used to solder large wires or when there is no
electricity at the jobsite. Whatever method you use,
be sure to apply solder on the side of the splice
opposite the point where you apply the heat. Figure
5-35 shows the three methods of soldering. The
melting solder will flow toward the source of heat.
Thus, if the top of the wire is hot enough to melt the
solder, the bottom of the wire closest to the heat
source will draw the solder down through all the
wires. Allow the splice to cool naturally without
moving it. Do not blow on the joint or dip it in water to
cool it. Rapid cooling will take all the strength out of a
solder joint. Once it is cooled, clean off any excess
flux with a damp rag, then dry and tape it.
Avoid breathing the fumes and smoke from
hot solder. Some solder contains lead which if
inhaled or ingested can cause lead poisoning.
Avoid prolonged skin contact with fluxes. Your
supervisor will give you a Material Safety Data
Sheet (MSDS) with the precautions for solder
Taping is required to protect the splice from
oxidation (formation of rust) and to insulate against
electrical shock. Taping should provide at least as
much insulation and mechanical protection for the
splice as the original covering. Although one wrap of
plastic (vinyl) tape will provide insulation protection
up to 600 volts, several wraps may be necessary to
provide good mechanical protection.
When plastic tape is used, it should be stretched as
it is applied. Stretching will secure the tape more
firmly. Figures 5-36 through 5-39 show the most
commonly used methods of taping splices.
Safety for the electrician today is far more
complicated than it was 20 years ago. But with proper
use of todays safeguards and safety practices, working
on electrical equipment can be safe. Electricity must be
respected. With common sense and safe work
practices, you can accomplish electrical work safely.