5, the overload device shall have sufficient time delay to permit the motor to start and accelerate its load.

(FPN): A Class 20 or 30 overload relay will provide a longer motor acceleration time than a Class 10 or 20, respectively. Use of a higher class overload relay may preclude the need for selection of a higher trip current. 430-35. Shunting During Starting Period. (a) Nonautomatically Started. For a nonautomatically started motor, the overload protection shall be permitted to be shunted or cut out of the circuit during the starting period of the motor if the device by which the overload protection is shunted or cut out cannot be left in the starting position and if fuses or inverse time circuit breakers rated or set at not over 400 percent of the full-load current of the motor are so located in the circuit as to be operative during the starting period of the motor. (b) Automatically Started. The motor overload protection shall not be shunted or cut out during the starting period if the motor is automatically started. Exception: The motor overload protection shall be permitted to be shunted or cut out during the starting period on an automatically started motor where: (1) The motor starting period exceeds the time delay of available motor overload protective devices, and (2) Listed means are provided to: a. Sense motor rotation and to automatically prevent the shunting or cutout in the event that the motor fails to start, and b. Limit the time of overload protection shunting or cutout to less than the locked rotor time rating of the protected motor, and C. Provide for shutdown and manual restart if motor running condition is not reached. 430-36. Fuses - In Which Conductor. Where fuses are used for motor overload protection, a fuse shall be inserted in each ungrounded conductor and also in the grounded conductor if the supply system is 3-wire, 3-phase ac with one conductor grounded. 430-37. Devices Other than Fuses - In Which Conductor. Where devices other than fuses are used for motor overload protection, Table 430-37 shall govern the minimum allowable number and location of overload units such as trip coils or relays. 430-38. Number of Conductors Opened by Overload Device. Motor overload devices other than fuses or thermal protectors shall simulta- 70-404 NATIONAL ELECTRICAL CODE Table 430-37. Overload Units Number and Location of Overload Units, such Kind of Motor Supply System as trip coils or relays 1-phase ac 2-wire, 1-phase ac or 1 in either conductor or dc dc ungrounded 1-phase ac 2 wire, 1-phase ac or dc, 1 in ungrounded conductor or dc one conductor grounded 1-phase ac 3-wire, 1-phase ac or 1 in either ungrounded or dc dc, grounded neutral conductor 1-phase ac Any 3-phase 1 in ungrounded conductor 2-phase ac 3-wire, 2-phase ac, 2, one in each phase ungrounded 2-phase ac 3-wire, 2-phase ac, one 2 in ungrounded conductors conductor grounded 2-phase ac 4-wire, 2-phase ac, 2, one per phase in ungrounded or ungrounded grounded conductors 2-phase ac 5-wire, 2-phase ac, 2, one per phase in any grounded neutral or ungrounded phase wire ungrounded 3-phase ac Any 3-phase 3, one in each phase* *Exception: Where protected by other approved means. neously open a sufficient number of ungrounded conductors to interrupt current flow to the motor. 430-39. Motor Controller as Overload Protection. A motor controller shall also be permitted to serve as an overload device if the number of overload units complies with Table 430-37 and if these units are operative in both the starting and running position in the case of a direct-current motor, and in the running position in the case of an alternating-current motor. 430-40. Overload Relays. Overload relays and other devices for motor overload protection that are not capable of opening short circuits shall be protected by fuses or circuit breakers with ratings or settings in accordance with Section 430-52 or by a motor short-circuit protector in accordance with Section 430-52. Exception No. 1: Where approved for group installation and marked to indicate the maximum size of fuse or inverse time circuit breaker by which they must be protected. Exception No. 2: The fuse or circuit breaker ampere rating shall be permitted to be marked on the nameplate of approved equipment in which overload relay is used. (FPN): For instantaneous trip circuit breakers or motor short-circuit protectors, see Section 430-52. 430-42. Motors on General-Purpose Branch Circuits. Overload protection for motors used on general-purpose branch circuits as permitted in rovided as specified in (a), (b), (c), or (d) below. ARTICLE 430 - MOTOR CIRCUITS, CONTROLLERS 70-405 (a) Not Over 1 Horsepower. One or more motors without individual overload protection shall be permitted to be connected to a generalpurpose branch circuit only where the installation complies with the limiting conditions specified in Sections 430-32(b) and (c) and Sections 430-53(a)(1) and (a)(2). (b) Over 1 Horsepower. Motors of larger ratings than specified in Section 430-53(a) shall be permitted to be connected to general-purpose branch circuits only where each motor is protected by overload protection selected to protect the motor as specified in Section 430-32. Both the controller and the motor overload device shall be approved for group installation with the short-circuit and ground-fault protective device selected in accordance with Section 430-53. (c) Cord- and Plug-Connected. Where a motor is connected to a branch circuit by means of an attachment plug and receptacle and individual overload protection is omitted as provided in (a) above, the rating of the attachment plug and receptacle shall not exceed 15 amperes at 125 volts, or 10 amperes at 250 volts. Where individual overload protection is required as provided in (b) above for a motor or motor-operated appliance that is attached to the branch circuit through an attachment plug and receptacle, the overload device shall be an integral part of the motor or of the appliance. The rating of the attachment plug and receptacle shall determine the rating of the circuit to which the motor may be connected, as provided in