UL 73:2004 pdf download – Motor-Operated Appliances. A terminal plate formed from stock having the thickness specified in may have themetal extruded at the tapped hole to provide two full threads for the binding screw. Upturmed lugs or a cupped washer shall be capable of retaining a supply conductor of the sizespecified in under the head of the screw or washer.
12.2.4 ldentified terminals and leads A permanently connected appliance rated 125 or 125/250 v(3-wire) or less and employing alampholder of the Edison-screw-shell type, or a single-pole switch or overcurrent-protective device otherthan an automatic control without a marked off position, shall have one terminal or lead identified for theconnection of the grounded conductor of the supply circuit. terminal intended for the connection of a grounded supply conductor shall be of or plated withmetal that is substantially white in color and shall be readily distinguishable from the other terminals,orproper identification of that terminal shall be clearly shown in some other manner, such as on an attachedwiring diagram. Alead intended for the connection of a grounded power-supply conductor shall be finished whiteor gray color and shall be readily distinguishable from the other leads.
13 current-Carrying Parts
13.1 A current-carrying part shall be of silver,copper,a copper alloy,stainless steel, or other similarmetal.
13.2 Ordinary iron or steel shall not be used as a current-carrying part.
Exception: Ordinary iron or steel provided with a corrosion-resistant coating may be used for acurrent-carrying part if acceptable in accordance with 3.1 or within a motor or associated governor.
14 Insulating Material
14.1 Material for mounting an uninsulated live part shall be porcelain, phenolic composition, or otherequivalent material.
14.2 Ordinary vulcanized fiber may be used for insulating bushings,washers,separators,and barriers,but not as the sole support for uninsulated live parts where shrinkage, current leakage, or warpage mayintroduce a risk of fire or electric shock.
14.3 A thermoplastic material generally is not considered acceptable for the sole support of uninsulatedlive parts,but may be employed if found to have the necessary mechanical strength and rigidity,resistance to heat,resistance to flame propagation, dielectric voltage withstand,and other appropriateproperties.
14.4 A small molded part, such as a brush cap, shall be constructed to have the necessary mechanicalstrength and rigidity to withstand the stresses of actual service.A brush cap shall be secured or locatedso that it is protected from mechanical damage that may result during intended use.
15 Internal Wiring
15.1 Mechanical protection
15.1.1 Wiring and connections between parts of an appliance shall be protected or enclosed.
Exception:A length of flexible cord may be employed for external connections if flexibility is essential.
15.1.2 Wires within an enclosure, a compartment, a raceway,or the like shall be routed or othenwiseprotected so that damage to conductor insulation cannot result from contact with any rough,sharp, ormoving part.
15.1.3 A hole through which insulated wires pass in a sheet-metal wall within the overall enclosure of anappliance shall be provided with a smooth, rounded bushing or shall have smooth, rounded surfaces uponwhich the wires may bear. A flexible cord used for external interconnection as mentioned in 15.1.1 shalbe provided with strain relief and bushings in accordance with the requirements in, andSection 46, Strain-Relief Test, unless the construction is such that the cord will be protected from stressand motion.
15.1.4 Insulated wires may be bunched and passed through a single opening in a metal wall within theenclosure of an appliance.
15.1.5 A conductor utlizing beads for insulation shall not be employed outside an enclosure.
15.1.6 Internal wiring shall consist of wires of a type or types that are acceptable for the application, whenconsidered with respect to the temperature and voltage to which the wiring is likely to be subjected andwith respect to its exposure to oil, grease, or other conditions of service to which it is likely to be subjected.15.1.7 Thermoplastic-insulated wire employed for internal wiring shall be standard building wire orappliance wiring material acceptable for the purpose.
15.1.8 With reference to exposure of insulated wiring through an opening in the enclosure of anappliance, the protection of such wiring required by 15.1.i is considered to exist if, when judged as thoughit were film-coated wire, the wiring would be acceptable according to 11.1 and 11.2. Internal wiring not soprotected may be accepted if it is secured within the enclosure so that it is unlikely to be subjected tostress or mechanical damage.