NOTE: practice, usually the case that all terminals are not
loaded simultaneously with the maximum permissible current.g.
For these cases, general rules cannot established and the limits
must determined for each individual case. This curve takes into account variations specimens as
well errors temperature measurements the measuring equipment.197), shall specified the relevant
detail specification. these factors result current-
carrying capacity other than that which may expected due thermal
limitations, then revised value shall apply.. the size the wire and unequal
distribution the loaded circuits.
.Corrected current-carrying capacity curve (derating curve)
A corrected current-carrying capacity curve (derating curve), derived from
the [.198: Example current-carrying capacity graph
The derating factor justified because the current-carrying capacity may
be limited further external factors, e.] basic curve (see figure 4. recommended that
the method described this standard used accordingly these
cases. 4. In
many cases, the individual terminals can carry several times the
derated current indicated the derating curve when less than %
of the total complement used..
158 ____________________________________________________________
0 fu3 <u2 tu\
Ambient temperature
Fig
