MIL-DTL-917 Electric Power Equipment, Basic Requirements ForThis specification covers the basic requirements applicable to the design, materials, and construction of naval shipboard electric power equipment \(exclusive of communication equipment, information technology \(IT\) equipment, and combat systems [fire control and weapons control equipment]\). Unless otherwise specified herein, the electric equipment developed for shipboard use under the requirements of this specification are limited to a maximum 450 volt \(V\) alternating current \(AC\) and a maximum 1,000 V direct current \(DC\). This equipment is intended for use on surface and submarine naval vessels \(see 6.2\).

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MIL-DTL-917F(SH)

3.19.3 Fuses, expulsion and current limiting fuses, and fuse disconnecting switches.

3.19.3.1 Fuses and fuse disconnecting switches design. 1,000 to 15,000-V fuses and fuse disconnecting

switches standard service conditions and definitions are defined in IEEE C37.40. Fuses and fuse disconnecting

switches shall be designed and tested in accordance with IEEE C37.42 and IEEE C37.47.

3.19.3.2 Expulsion and current limiting fuses and fuse disconnecting switches design. Expulsion and current

limiting fuses and fuse disconnecting switches shall be designed and tested in accordance with IEEE C37.46.

3.19.3.3 Fuses, expulsion and current limiting fuses, and fuse disconnecting switches application, operation,

coordination, and maintenance. 1,000 to 15,000-V fuses, expulsion and current limiting fuses, and fuse

disconnecting switches shall be applied, operated, coordinated, and maintained in accordance with IEEE C37.48 and

IEEE C37.48.1.

3.19.4 Circuit breakers.

3.19.4.1 Circuit breakers. 1,000 to 15,000-V circuit breakers shall be designed, rated, constructed, and tested

in accordance with IEEE C37.04 and IEEE C37.09. Preferred circuit breaker for primary power shall be vacuum

type (VCB) and shall be Navy-approved (see 6.2).

3.19.4.2 Generator circuit breakers. Generator circuit breakers shall be designed, rated, constructed, and tested

in accordance with IEEE C37.013.

3.19.5 Switches. 1,000 to 15,000-V switches shall be designed, rated, and tested in accordance with

IEEE C37.20.4.

3.19.6 Relays. 1,000 to 15,000-V relays and relay systems used to protect and control power apparatus

standard service conditions, standard ratings, performance requirements, and testing requirements are specified in

IEEE C37.90. Surge tests shall be in accordance with IEEE C37.90.1 and standardized waveforms that are

representative of surges observed and measured in actual installations should be applied to the terminals of the relay

system. The relay or relay system shall be able to withstand the applied surges without damage to components and

without operating incorrectly. Susceptibility tests shall be in accordance with IEEE C37.90.2. Tests conducted on

the relay or relay system should evaluate the susceptibility of the relays and relay system under frequencies they will

be subjected to aboard ship.

3.19.7 Insulators. 1,000 to 15,000-V insulators for oil-filled transformers and oil-filled reactors shall have the

requirements of IEEE C57.19 and have these requirements verified by the tests defined in IEEE C57.19.

3.19.8 Current transformers. Current transformers shall meet the requirements of IEEE C57.13. Iron core

current transformer coil output current shall be analog signals. When specified (see 6.2), alternatives to current

transformers shall be allowed that meet the applicable performance requirements of IEEE C57.13. Rogowski

current transformers shall meet the application characteristics of IEEE C37.235 and testing requirements of

IEC 60044-8.

3.19.9 Maintenance safety.

3.19.9.1 Partial discharge detection maintenance equipment. When specified (see 6.2), maintenance test

equipment capable of detecting partial discharge shall be provided. The test equipment used shall be capable of

operation in the field for maintenance. Partial Discharge Inception Voltage (PDIV) shall not be detectible below the

level specified (see 6.2). The procedures for detecting partial discharge shall be verified during first article testing

in accordance with IEEE C37.301 (see 4.6.4).

3.19.9.2 Capacitive voltage indicating systems. When specified (see 6.2), Voltage Detection System (VDS) in

accordance with IEC 61243-5 or Voltage Presence Indicating System (VPIS) in accordance with IEC 62271-206

shall be provided. The capacitive outlets of the voltage detection system shall provide the interface for the

maintenance partial discharge system (if applicable). Voltage indicators (LEDs) shall be provided for voltage

presence detection.