[Code of Federal Regulations]
[Title 46, Volume 4]
[Revised as of October 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR111.30-17]

[Page 225]
 
                           TITLE 46--SHIPPING
 
    CHAPTER I--COAST GUARD, DEPARTMENT OF TRANSPORTATION (CONTINUED)
 
PART 111--ELECTRIC SYSTEMS--GENERAL REQUIREMENTS--Table of Contents
 
                      Subpart 111.30--Switchboards
 
Sec. 111.30-17  Protection of instrument circuits.

    (a) Each circuit that supplies a device on a switchboard, except a 
circuit under paragraph (b) of this section, must have overcurrent 
protection.
    (b) A circuit that supplies a device on a switchboard must not have 
overload protection if it supplies:
    (1) An electric propulsion control;
    (2) A voltage regulator;
    (3) A ship's service generator circuit breaker tripping control; or
    (4) A device that creates a hazard to the vessel if deenergized.
    (c) If short circuit protection is used in any of the circuits 
listed in paragraph (b) of this section, it must be set at not less than 
500% of the expected current.
    (d) A secondary circuit of a current transformer must not be fused, 
and the circuit from a current transformer to a device that is not in 
the switchboard must have a high voltage protector to short the 
transformer during an open circuit.

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