4.4.3 - Joints and terminations
The normal installation has many joints,
and it follows that these must all remain safe and effective
throughout the life of the system. With this in mind, regulations
on joints include the following:
1.
- All joints must be durable, adequate for their
purpose, and mechanically strong.
2.
- They must be constructed to take account of the
conductor material and insulation, as well as temperature:
eg, a soldered joint must not be used where the temperature
may cause the solder to melt or to weaken. Very large expansion
forces are not uncommon in terminal boxes situated at the
end of straight runs of large cables when subjected to overload
or to fault currents.
3. - All joints and connections
must be made in an enclosure complying with the appropriate
British Standard.
4. - Where sheathed cables are used,
the sheath must be continuous into the joint enclosure {Figure
4.17}.
5.
- All joints must be accessible for inspection and
testing unless they are buried in compound or encapsulated,
are between the cold tail and element of a heater such as
a pipe tracer or underfloor heating system, or are made
by soldering, welding, brazing or compression.
Fig 4.17 Failure to enclose
non-sheathed cables
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