Article 670

Industrial Machinery

1. Scope. This article covers the definition of, the name‐ plate data for, and the size and overcurrent protection of supply conductors to industrial machinery.Informational Note No. 1: For further information, see NFPA 79 -2015, Electrical Standard for Industrial Machinery.Informational Note No. 2: For information on the workspace requirements for equipment containing supply conductor termi‐ nals, see 110.26. For information on the workspace require‐ ments for machine power and control equipment, see NFPA 79 -2015, Electrical Standard for Industrial Machinery.
2. Definition.Industrial Machinery (Machine). A power-driven machine (or a group of machines working together in a coordinated manner), not portable by hand while working, that is used to process material by cutting; forming; pressure; electrical, ther‐ mal, or optical techniques; lamination; or a combination of these processes. It can include associated equipment used to transfer material or tooling, including fixtures, to assemble/ disassemble, to inspect or test, or to package. [The associated electrical equipment, including the logic controller(s) and associated software or logic together with the machine actua‐ tors and sensors, are considered as part of the industrial machine.]
3. Machine Nameplate Data.Informational Note: See 430.22(E) and 430.26 for duty cycle requirements.
   1. Permanent Nameplate. A permanent nameplate shall be attached to the control equipment enclosure or machine and shall be plainly visible after installation. The nameplate shall include the following information:
      1. Supply voltage, number of phases, frequency, and full- load current
      2. Maximum ampere rating of the short-circuit and ground- fault protective device
      3. Ampere rating of largest motor, from the motor name‐ plate, or load
      4. Short-circuit current rating of the machine industrial control panel based on one of the following:
         1. Short-circuit current rating of a listed and labeled machine control enclosure or assembly
         2. Short-circuit current rating established utilizing an approved methodInformational Note: UL 508A-2001, Supplement SB, is an example of an approved method.
      5. Electrical diagram number(s) or the number of the index to the electrical drawings
      The full-load current shown on the nameplate shall not be less than the sum of the full-load currents required for all motors and other equipment that may be in operation at the same time under normal conditions of use. Where unusual type loads, duty cycles, and so forth require oversized conduc‐ tors or permit reduced-size conductors, the required capacity shall be included in the marked “full-load current.” Where more than one incoming supply circuit is to be provided, the nameplate shall state the preceding information for each circuit.
   2. Overcurrent Protection. Where overcurrent protection is provided in accordance with 670.4(C), the machine shall be marked “overcurrent protection provided at machine supply terminals.”
4. Supply Conductors and Overcurrent Protection.

1. Size. The size of the supply conductor shall be such as to have an ampacity not less than 125 percent of the full-load current rating of all resistance heating loads plus 125 percent of the full-load current rating of the highest rated motor plus the sum of the full-load current ratings of all other connected motors and apparatus, based on their duty cycle, that may be in operation at the same time.Informational Note No. 1: See Table 310.15(B)(16) through Table 310.15(B)(20) for ampacity of conductors rated 2000 volts and below.Informational Note No. 2: See 430.22(E) and 430.26 for duty cycle requirements.
2. Disconnecting Means. A machine shall be considered as an individual unit and therefore shall be provided with discon‐ necting means. The disconnecting means shall be permitted to be supplied by branch circuits protected by either fuses or circuit breakers. The disconnecting means shall not be required to incorporate overcurrent protection.
3. Overcurrent Protection. Where furnished as part of the machine, overcurrent protection for each supply circuit shall consist of a single circuit breaker or set of fuses, the machine shall bear the marking required in 670.3, and the supply conductors shall be considered either as feeders or as taps as covered by 240.21.

The rating or setting of the overcurrent protective device for the circuit supplying the machine shall not be greater than the sum of the largest rating or setting of the branch-circuit short- circuit and ground-fault protective device provided with the machine, plus 125 percent of the full-load current rating of all

ARTICLE 675 — ELECTRICALLY DRIVEN OR CONTROLLED IRRIGATION MACHINES 675.7

resistance heating loads, plus the sum of the full-load currents of all other motors and apparatus that could be in operation at the same time.

Exception: Where one or more instantaneous trip circuit breakers or motor short-circuit protectors are used for motor branch-circuit short- circuit and ground-fault protection as permitted by 430.52(C), the procedure specified in 670.4(C) for determining the maximum rating of the protective device for the circuit supplying the machine shall apply with the following provision: For the purpose of the calculation, each instantaneous trip circuit breaker or motor short-circuit protector shall be assumed to have a rating not exceeding the maximum percentage of motor full-load current permitted by Table 430.52 for the type of machine supply circuit protective device employed.

Where no branch-circuit short-circuit and ground-fault protective device is provided with the machine, the rating or setting of the overcurrent protective device shall be based on

430.52 and 430.53, as applicable.

1. Short-Circuit Current Rating.•
   1. Industrial machinery shall not be installed where the avail‐able short-circuit current exceeds its short-circuit current rating as marked in accordance with 670.3(A)(4).N
   2. Industrial machinery shall be legibly marked in the field with the maximum available short-circuit current. The field marking(s) shall include the date the short-circuit current calculation was performed and be of sufficient durability to withstand the environment involved.
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2. Surge Protection. Industrial machinery with safety interlock circuits shall have surge protection installed.