[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR183.380]

[Page 294-295]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 183_ELECTRICAL INSTALLATION--Table of Contents
 
            Subpart C_Power Sources and Distribution Systems
 
Sec. 183.380  Overcurrent protection.

    (a) Overcurrent protection must be provided for each ungrounded 
conductor for the purpose of opening the

[[Page 295]]

electric circuit if the current reaches a value that causes an excessive 
or dangerous temperature in the conductor or conductor insulation.
    (b) The grounded conductor of a circuit must not be disconnected by 
a switch or circuit breaker, unless the ungrounded conductors are 
simultaneously disconnected.
    (c) A conductor of a control, interlock, or indicator circuit, such 
as a conductor for an instrument, pilot light, ground detector light, or 
potential transformer, must be protected by an overcurrent device.
    (d) Conductors must be protected in accordance with their current 
carrying capacities. If the allowable current carrying capacity does not 
correspond to a standard device size, the next larger overcurrent device 
may be used provided it does not exceed 150 percent of the conductor 
current carrying capacity.
    (e) Steering gear control system circuits must be protected against 
short circuit.
    (f) Each steering gear feeder circuit must be protected by a circuit 
breaker that meets the requirements of Sec. 58.25-55 in subchapter F of 
this chapter.
    (g) Each lighting branch circuit must be protected against 
overcurrent either by fuses or circuit breakers rated at not more than 
30 amperes.
    (h) Overcurrent devices capable of carrying the starting current of 
the motor must be installed to protect motors, motor conductors, and 
control apparatus against:
    (1) Overcurrent due to short circuits or ground faults; and
    (2) Overload due to motor running overcurrent, in accordance with 
Sec. 111.70-1 in subchapter J of this chapter. A protective device 
integral with the motor, which is responsive to both motor current and 
temperature, may be used.
    (i) An emergency switch must be provided in the normally ungrounded 
main supply conductor from a battery. The switch must be accessible and 
located as close to the battery as practicable.
    (j) Disconnect means must be provided on the supply side of and 
adjacent to all fuses for the purpose of de-energizing the fuses for 
inspection and maintenance purposes.
    (k) If the disconnect means is not within sight of the equipment 
that the circuit supplies, means must be provided for locking the 
disconnect device in the open position.
    (l) Fuses must be of the cartridge type only and be listed by 
Underwriters Laboratories or another independent laboratory recognized 
by the Commandant.
    (m) Each circuit breaker must meet UL 489, ``Molded--Case Circuit 
Breakers and Circuit Breaker Enclosures,'' or other standard specified 
by the Commandant, and be of the manually reset type designed for:
    (1) Inverse time delay;
    (2) Instantaneous short circuit protection; and
    (3) Switching duty if the breaker is used as a switch.
    (n) Each circuit breaker must indicate whether it is in the open or 
closed position.

[CGD 85-080, 61 FR 997, Jan. 10, 1996, as amended by CGD 97-057, 62 FR 
51050, Sept. 30, 1997; USCG-2002-13058, 67 FR 61279, Sept. 30, 2002]