(1) In Accordance with Table 430.52. A protective de- vice that has a rating or setting not exceeding the value calculated according to the values given in Table 430.52 shall be used.

Note: For certain exceptions to the values specified, see
430.54. 'The values in the Nontime Delay Fuse column apply to
Time-Delay Class CC fuses.

2The values given in the last column also cover the ratings of nonadjustable inverse time types of circuit breakers that may be modified as in 430.52(C)(1), Exception No. 1 and No. 2.

3Synchronous motors of the low-torque, low-speed type (usually

450 rpm or lower), such as are used to drive reciprocating compressors, pumps, and so forth, that start unloaded, do not require a fuse rating or circuit-breaker setting in excess of 200
percent of full-load current.

mitted to be increased but shall in no case exceed 400 percent of the full-load current.

(b) The rating of a time-delay (dual-element) fuse shall be permitted to be increased but shall in no case exceed 225 percent of the full-load current.

(c) The rating of an inverse time circuit breaker shall

be permitted to be increased but shall in no case exceed

400 percent for full-load currents of 100 amperes or less or 300 percent for full-load currents greater than 100 amperes.

(d) The rating of a fuse of 601-6000 ampere classifi- cation shall be permitted to be increased but shall in no case.exceed 300 percent of the full-load current.

FPN: See Annex D, Example D8, and Figure 430.1.

(2) Overload Relay Table. Where maximum branch- circuit short-circuit and ground-fault protective device ratings are shown in the manufacturer's overload relay table for use with a motor controller or are otherwise marked on the equipment, they shall not be exceeded even if higher values are allowed as shown above.

(3) Instantaneous Trip Circuit Breaker. An instantaneous trip circuit breaker shall be used only if adjustable and if part of a listed combination motor controller having coordinated motor overload and short-circuit and groundfault protection in each conductor, and the setting is adjusted to no more than the value specified in Table 430.52.

FPN: For the purpose of this article, instantaneous trip circuit breakers may include a damping means to accommodate a transient motor inrush current without nuisance tripping of the circuit breaker.

Exception No. 1: Where the setting specified in Table

430.52 is not sufficient for the starting current of the

motor, the setting of an instantaneous trip circuit

breaker shall be permitted to be increased but shall in

no case exceed 1300 percent of the motor full-load

current for other than Design B energy-efficient motors

and no more than 1700 percent of full-load motor

current for Design B energy-efficient motors. Trip

settings above 800 percent for other than Design B

energy-efficient motors and above 1100 percent for

Design B energy-efficient motors shall be permitted

where the need has been demonstrated by engineering

evaluation. In such cases, it shall not be necessary to

first apply an instantaneous-trip circuit breaker at 800

percent or 1100 percent.

FPN: For additional information