CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER J—ELECTRICAL ENGINEERING (parts 110 to 113) > PART 112—EMERGENCY LIGHTING AND POWER SYSTEMS > SUBPART 112.05—General (§112.05-1 to §112.05-5) > 112.05-3—Main-emergency bus-tie.

112.05-3—Main-emergency bus-tie.

Each bus-tie between a main switchboard and an emergency switchboard must:
(a) Disconnect automatically upon loss of potential at the emergency switchboard;
(b) Be arranged to prevent parallel operation of an emergency power source with any other source of electric power, except for interlock systems for momentary transfer of loads; and
(c) If arranged for feedback operation, open automatically upon overload of the emergency power source before the emergency power source is tripped off the line from the overload.