// CODE SNIPPET
430.12 Motor Terminal Housings
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(A) Material
Where motors are provided with terminal housings, the housings shall be of metal and of substantial construction.
(B) Dimensions and Space — Wire-to-Wire Connections
Where these terminal housings enclose wire-to-wire connections, they shall have minimum dimensions and usable volumes in accordance with Table 430.12(B).
Motors 275 mm (11 in.) in Diameter or Less | |||||||
---|---|---|---|---|---|---|---|
Horsepower | Cover Opening Minimum Dimension | Usable Volume Minimum | |||||
mm | in. | cm3 | in.3 | ||||
1 and smallera | 41 | 15/8 | 170 | 10.5 | |||
11/2, 2, and 3b | 45 | 13/4 | 275 | 16.8 | |||
5 and 71/2 | 50 | 2 | 365 | 22.4 | |||
10 and 15 | 65 | 21/2 | 595 | 36.4 | |||
Motors Over 275 mm (11 in.) in Diameter — Alternating-Current Motors |
Maximum Full Load Current for 3-Phase Motors with Maximum of 12 Leads (Amperes) | Terminal Box Cover Opening Minimum Dimension | Usable Volume Minimum | Typical Maximum Horsepower 3-Phase | |||||
---|---|---|---|---|---|---|---|---|
mm | in. | cm3 | in.3 | 230 Volt | 460 Volt | |||
45 | 65 | 2.5 | 595 | 36.4 | 15 | 30 | ||
70 | 84 | 3.3 | 1,265 | 77 | 25 | 50 | ||
110 | 100 | 4.0 | 2,295 | 140 | 40 | 75 | ||
160 | 125 | 5.0 | 4,135 | 252 | 60 | 125 | ||
250 | 150 | 6.0 | 7,380 | 450 | 100 | 200 | ||
400 | 175 | 7.0 | 13,775 | 840 | 150 | 300 | ||
600 | 200 | 8.0 | 25,255 | 1540 | 250 | 500 |
Direct-Current Motors | |||||||
---|---|---|---|---|---|---|---|
Maximum Full-Load Current for Motors with Maximum of 6 Leads (Amperes) | Terminal Box Minimum Dimensions | Usable Volume Minimum | |||||
mm | in. | cm3 | in.3 | ||||
68 | 65 | 2.5 | 425 | 26 | |||
105 | 84 | 3.3 | 900 | 55 | |||
165 | 100 | 4.0 | 1,640 | 100 | |||
240 | 125 | 5.0 | 2,950 | 180 | |||
375 | 150 | 6.0 | 5,410 | 330 | |||
600 | 175 | 7.0 | 9,840 | 600 | |||
900 | 200 | 8.0 | 18,040 | 1,100 | |||
Note: Auxiliary leads for such items as brakes, thermostats, space heaters, and exciting fields shall be permitted to be neglected if their current-carrying area does not exceed 25 percent of the current-carrying area of the machine power leads. | |||||||
aFor motors rated 1 hp and smaller, and with the terminal housing partially or wholly integral with the frame or end shield, the volume of the terminal housing shall not be less than 18.0 cm3 (1.1 in.3) per wire-to-wire connection. The minimum cover opening dimension is not specified. | |||||||
bFor motors rated 11/2, 2, and 3 hp, and with the terminal housing partially or wholly integral with the frame or end shield, the volume of the terminal housing shall not be less than 23.0 cm3 (1.4 in.3) per wire-to-wire connection. The minimum cover opening dimension is not specified. |
(C) Dimensions and Space — Fixed Terminal Connections
Where these terminal housings enclose rigidly mounted motor terminals, the terminal housing shall be of sufficient size to provide minimum terminal spacings and usable volumes in accordance with Table 430.12(C)(1) and Table 430.12(C)(2).
Nominal Volts | Minimum Spacing | ||||
---|---|---|---|---|---|
Between Line Terminals | Between Line Terminals and Other Uninsulated Metal Parts | ||||
mm | in. | mm | in. | ||
250 or less | 6 | 1/4 | 6 | 1/4 | |
Over 250 — 1000 | 10 | 3/8 | 10 | 3/8 |
Table 430.12(C)(2) Usable Volumes — Fixed Terminals
Power-Supply Conductor Size (AWG) | Minimum Usable Volume per Power-Supply Conductor | |
---|---|---|
cm3 | in.3 | |
14 | 16 | 1 |
12 and 10 | 20 | 11/4 |
8 and 6 | 37 | 21/4 |
(D) Large Wire or Factory Connections
For motors with larger ratings, greater number of leads, or larger wire sizes, or where motors are installed as a part of factory-wired equipment, without additional connection being required at the motor terminal housing during equipment installation, the terminal housing shall be of ample size to make connections, but the foregoing provisions for the volumes of terminal housings shall not be considered applicable.
(E) Equipment Grounding Connections
A means for attachment of an equipment grounding conductor termination in accordance with 250.8 shall be provided at motor terminal housings for wire-to-wire connections or fixed terminal connections. The means for such connections shall be permitted to be located either inside or outside the motor terminal housing.
Exception: Where a motor is installed as a part of factory-wired equipment that is required to be grounded and without additional connection being required at the motor terminal housing during equipment installation, a separate means for motor grounding at the motor terminal housing shall not be required.
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