to be used in lieu of a box at the end of a rigid metal conduit, intermediate metal conduit, or electrical metallic tubing where the raceway terminates at unenclosed controls or similar equipment, including contact conductors, collectors, resistors, brakes, power- circuit limit switches, and dc split-frame motors.
610.13 Types of Conductors. Conductors shall comply with Table 310.13(A) unless otherwise permitted in
610.13(A) through (D).
(A) Exposed to External Heat or Connected to Resis- tors. A conductor(s) exposed to external heat or connected to resistors shall have a flame-resistant outer covering or be covered with flame-resistant tape individually or as a group.
(B) Contact Conductors. Contact conductors along run- ways, crane bridges, and monorails shall be permitted to be bare and shall be copper, aluminum, steel, or other alloys or combinations thereof in the form of hard- drawn wire, tees, angles, tee rails, or other stiff shapes.
(C) Flexibility. Where flexibility is required, flexible cord or cable shall be permitted to be used and, where necessary, cable reels or take-up devices shall be used.
(D) Class 1, Class 2, and Class 3 Circuits. Conductors for Class 1, Class 2, and Class 3 remote-control, signaling, and power-limited circuits, installed in accordance with Article 725, shall be permitted.
610.14 Rating and Size of Conductors.
(A) Ampacity. The allowable ampacities of conductors shall be as shown in Table 610.14(A).
FPN: For the ampacities of conductors between controllers and resistors, see 430.23.
(B) Secondary Resistor Conductors. Where the second- ary resistor is separate from the controller, the minimum size of the conductors between controller and resistor shall be calculated by multiplying the motor secondary current by the appropriate factor from Table 610.14(B) and selecting a wire from Table
610.14(A).
(C) Minimum Size. Conductors external to motors and controls shall be not smaller than 16 AWG unless otherwise permitted in (1) or (2):
(1) 18 AWG wire in multiconductor cord shall be permitted for control circuits not exceeding 7 amperes.
(2) Wires not smaller than 20 AWG shall be permitted for electronic circuits.
Table 610.14(A) Ampacities of Insulated Copper Conductors Used with Short-Time Rated Crane and Hoist Motors. Based on Ambient
Temperature of 30°C (86°F).
|
Maximum Operating Temperature |
Up to Four Simultaneously Energized Conductors in Raceway or Cable 1 |
Up to Three ac 2 or Four dc 1 Simultaneously Energized Conductors in Raceway |
Maximum Operating Temperature |
||||
|
Maximum Operating Temperature |
75°C (167°F) |
90°C (194°F) |
125°C (257°F) |
Maximum Operating Temperature |
|||
|
Size (AWG or kcmil) |
Types MTW, RHW, THW, THWN, XHHW, USE, ZW |
Types TA, TBS, SA, SIS, PFA, FEP, FEPB, RHH, THHN, XHHW, Z, ZW |
Types FEP, FEPB, PFA, PFAH, SA, TFE, Z, ZW |
Size (AWG or kcmil) |
|||
|
Size (AWG or kcmil) |
60Min |
30Min |
60Min |
30Min |
60Min |
30Min |
Size (AWG or kcmil) |
|
16 14 12 |
10 25 30 40 55 |
12 26 33 43 60 |
31 36 49 63 |
32 40 52 69 |
38 45 60 73 |
40 50 65 80 |
16 14 12 10 8 |
|
6 5 4 3 2 1 |
76 85 100 120 137 143 |
86 95 117 141 160 175 |
83 95 111 131 148 158 |