3.1.30 Encapsulated motor suitability tests. - Where encapsulated motors are used, encapsulated
motor suitability tests in accordance with the procedures of appendix II shall be conducted and Bureau of
Ships approval shall be obtained prior to acceptance of any motor for shipment under a contract or order.
3.1.31 Life. - Except for the bearings and brushes, the motor and the insulation system shall be de-
signed for a minimum of 40, 000 hours of operation over a period of 20 years. Brushes shall be selected
for a minimum of 8, 000 hours of operation. Bearings shall be selected to insure a minimum B-10 life of
3.1.32 Interchangeability. - All similar parts, including repair parts supplied for replacement purpose,
furnished to the same drawings or sets of drawings shall be strictly interchangeable without the necessity of
further machining, selective assembly or hand fitting.
3.2 Identification plates. -
3.2.1 General. - The identification plates (and information plates where required) shall be attached to
the part of the machinery or equipment which will not ordinarily be renewed during its normal service life.
These plates shall be located where they can be read at all times without danger to personnel. Identification
plates and information plates shall be made of brass , nickel-copper-alloy or corrosion resistant steel. The
markings shall be either etched, stamped, engraved, metal-photo on anodized aluminum or cast in such a
manner as to produce permanent and durable markings to last the anticipated life of the equipment, All etch-
ings, engravings or stampings shall not be less than .003 inch deep. The characters on cast plates shall be
raised to at least 0.03 inch. All engraved stamped or direct etched markings shall be filled with black paint
enamel or lacquer.
3.2.2 Identification plate markings. - The minimum data to be marked on the identification plate for
motors shall include the following items:
220.127.116.11 Motors rated less than 1/20 hp. -
Power output (millihorsepower-mhp).
Number of phasespolyphase only (this may be designated by a number showing the number of
phases following the frequency).
The words "thermal protection" for motors equipped with inherent overheating protective
Federal stock number.
Government contract number.
Year of manufacture.
Blank space for Government inspector's official stamp.
This speed is the approximate full-load speed.
These words may be shown on a separate plate.
18.104.22.168 Alternating-current single-phase and polyphase squirrel-cage motors larger than 1/20
Manufacturer's type and frame designation.
Maximum ambient temperature for which motor is designed.
Insulation system designation.
R.p.m. at rated load.
Number of phases.