Any number and any type of Class 1 circuit
conductors may be installed in the same conduit,
raceway, box, or other enclosure if all conductors are
insulated for the maximum voltage at which any of the
conductors operates and the wires are functionally
associated with each other.
Class 1 circuit wires may be run in raceways by
themselves according to the NEC®. The number of
conductors in a conduit must be determined from
tables 1 through 5 in chapter 9 of the NEC®).
In figures 7-11 and 7-12, you see the electrical symbols
that conform to the standards established by the National
Electrical Manufacturers Association (NEMA). Where
NEMA standards do not exist, American Standards
Association (ASA) standards are used; however, not all
manufacturers use these established symbols. In spite of the
lack of standardization, knowledge of the symbols
presented in this unit will give you a firm basis for
interpreting variations found in the field.
Figure 7-11.Standard wiring diagram symbols.