Code of Federal Regulations Title 46. Shipping § 46.111.70–1 General

(a) Each motor circuit, controller, and protection must meet the requirements of ABS Steel Vessel Rules, sections 4–8–2/9.17, 4–8–3/5.7.3, 4–8–4/9.5, and 4–8–3/5;  ABS MODU Rules, Part 4, Chapter 3, sections 4/7.11 and 4/7.17;  or IEC 60092–301 (all three standards incorporated by reference;  see 46 CFR 110.10–1), as appropriate, except for the following circuits:

(b) In ungrounded three-phase alternating current systems, only two motor-running protective devices (overload coil or heater type relay within the motor and controller) need be used in any two ungrounded conductors, except when a wye-delta or a delta-wye transformer is used.

(c) The motor disconnecting means must be an externally operable switch or circuit breaker.