locked in the open-circuit position by means of a padlock or the equivalent. The switch shall have no provisions for locking in the closed-circuit position.

(d) Detail construction requirements (1) Enclosures. Each enclosure for motor controller and switching devices, when installed in locations exposed to the weather, shall be capable of meeting the test requirements of paragraph (e) of this section.

(2) Electrical clearances. The minimum creepage and air clearance distance between live parts of different polarity of motor controllers, master switches, and control circuit limit switches shall be not less than the values shown in Table 111.65-40 (d) (2). It is desirable to exceed these values where possible. The electrical clearances for power circuit limit switches and main line emergency disconnect switches shall be not less than the general requirements for such devices given in this part.

(3) Motors. Motors shall be of waterproof construction in accordance with the general requirements of this part. TAPLE 111.65-40 (d) (2)—MINIMUM SPACINGS IN INCHES

(e) Spraytight test. (1) Before conducting this test, all joints that have gaskets or sealing compounds, or that have been painted, shall be broken and reassembled three times; this procedure also applies to doors and to cover plates. There shall be no leakage of water into the enclosure after it has been subjected to one of the following methods of submergence for a period of five continuous minutes:

(i) The enclosure shall be submerged in water to such a depth that the highest point of the enclosure in its normally mounted position is under a three-foot head; or

(ii) The enclosure shall be submerged in water at least 3 inches at the highest point in an open tank. Sufficient vacuum shall then be applied to the inside of the enclosure to produce an external pressure equivalent to a 3-foot head of water.

(2) The following additional test shall be conducted immediately after either of the above tests, and while the enclosure is still submerged. An internal air pressure shall be applied for a period of 5 minutes equal to 11⁄2 pounds per square inch, plus a pressure equivalent to the depth of submergence.

(3) Under these tests the enclosure will be considered spraytight if no water is found inside the enclosure, and if no air bubbles are seen to emerge. Where a shaft enters the enclosure, the shaft shall be operated twice while submerged. (4) The following formula may be used to determine the necessary vacuum: M-0.074 (12H-W)

where:

(1)

M=vacuum in inches of mercury,
H=equivalent head of water in feet, and
W depth of water in inches covering the
highest point of the enclosure.

(f) Wiring of lifeboat winch components. (1) When the motor controller of a lifeboat winch power unit is located adjacent to the winch, the main line emergency switch shall disconnect all parts of the lifeboat winch power unit, including the motor controller and limit switches, from all sources of potential. Any other power circuit switches employed shall be connected in series with the main line emergency switch and ahead of the motor controller. The main line emergency switch shall serve as the motor and controller disconnect required by the general requirements of this part, and shall have a horsepower rating not less than that of the winch motor.

(2) When the motor controller of a lifeboat winch power unit is remotely located with relation to the winch, a switch shall be provided at the controller arranged to disconnect the entire winch electrical installation from all sources of potential. In such cases, the main line emergency switch shall be connected in series with this circuit disconnect switch and ahead of the power circuit limit switches, when employed, and ahead of the motor controller.

(3) Davit arm limit switches, whether connected in the power circuit or in the control circuit, shall disconnect all ungrounded conductors of the circuit controlled.

(4) Where one motor is used with two winches, a main line emergency switch, a clutch interlock switch, and a master switch shall be provided for each winch, except that a single main line emergency switch located in accordance with subparagraph (5) of this paragraph with respect to both winches will be accepted. The main line emergency switches shall be connected in series ahead of the motor controller. The master switches shall be connected in parallel and each in series with the corresponding clutch interlock switch for that winch. The clutch interlock switches shall open the circuit to its master switch except when the power unit is clutched to the associated winch. Means shall be provided to prevent the power unit from being clutched to both winches simultaneously.

(5) Typical lifeboat winch wiring diagrams and arrangement drawings are shown on Figures 111.65-40 (f) (5) (i) through 111.65-40 (f) (5) (iv), the arrangement of the equipment shown being diagrammatical. The fact that some show direct current motors and some show alternating current motors has no particular significance. In actual installations the main line emergency disconnect switch shall be so located as to be adjacent to the master switch; within reach of the winch operator; in a position accessible to the person in charge of the boat stowage; and in a position, for gravity davit installations, from which the movement of both davit arms can be observed as they approach the final stowed position. Special consideration will be given to other arrangements where complete compliance with these location requirements cannot be met.

(g) Procedure for approval of lifeboat winch electrical installations and equipment (1) Switches. Manufacturers of master switches, limit switches, and main line emergency disconnect switches desiring to qualify their products for use in connection with lifeboat winch installations shall submit for review detail assembly drawings of the unit, identifying each part used in the assembly and the material specification, including fin

ish, if any, of each part. After the detail assembly drawings have been reviewed sample units may be requested for testing. Units found to comply with the requirements of this section will be listed by the Coast Guard as being satisfactory for use as lifeboat winch auxiliary equipment.

(2) Motor controllers. Manufacturers of motor controllers desiring to qualify their products for use in conjunction with lifeboat winch installations shall submit for review detail assembly drawings and material lists of the enclosing cases to be furnished, and detail assembly drawings and material lists and/or samples of contactors, relays, resistors and other motor controller components to be employed. For each installation of lifeboat winch motor controllers there shall be submitted for approval a drawing showing the enclosure outline, front view assembly, wiring diagram, and material list, together with the name or other identification of the vessel on which the motor controllers will be installed. No general approval of motor controllers will be given.

(3) Motors. For each installation of lifeboat winch motors, plans as required by § 111.05-5 shall be submitted, together with the name or other identification of the vessel on which the motor will be installed. No general approval of motors will be given.

(4) Shipboard installation drawing. For each shipboard installation of electric power-operated lifeboat winches, an elementary wiring diagram and isometric or deck wiring diagram as required by § 111.05-5 shall be submitted.

(h) Testing of lifeboat winch electrical equipment. The electrical equipment shall be given periodic inspections and tests as required by Part 78 of Subchapter H (Passenger Vessels) and Part 97 of Subchapter I (Cargo and Miscellaneous Vessels) of this chapter.

(i) Electric power-operated lifeboat winches for existing vessels. (1) The electrical equipment installed in connection with electric power-operated lifeboat winches used with gravity davits on passenger vessels and cargo vessels contracted for prior to November 19, 1952, and on tank vessels contracted for on or after November 19, 1952 shall comply with the requirements of § 160.015-3 (k) of Subchapter Q (Specifications) of this chapter and with the wiring arrangements of § 111.65-40 (f).

MAIN LINE EMERGENCY DISCONNECT SWITCH

With external operating handle and having horsepower rating not less than that of motor. Required by Sub-paragraph 160.015-3(k) (1), revised.

FIGURE 111.65-40 (f) (5) (1)-Typical elementary wiring diagram and arrangement plan of gravity davit and boat winch employing doublepole limit switches and main line emergency switch in accordance with Subpart 160.015, Subchapter Q.

FIGURE 111.65-40 (f) (5) (11)-Typical elementary wiring diagram and arrangement plan of gravity davits and dual boat winch employing double-pole limit switches, clutch interlock switches, and main line emergency switches in accordance with Subpart 160.018, Subchapter Q.

TYPICAL FULL VOLTAGE MAGNETIC ALTERNATING-CURRENT MOTOR CONTROLLER

With min line emergency disconnect switch having horsepower rating not less than
that of motor and with external operating handle.

Required by Sub-paragraph 160.015–3(k)(1), revised.

MASTER SWITCH

Spring Return to OFF.

Required by Paragraph 160.015-3(J).

Right Hand Davit Arm. Required by Sub-paragraph 160.015-3(k)(2), revised. POWER LIMIT SWITCH

Left Hand Davit Arm. Required by Sub-paragraph 160.015-3(k)(2), revised.

FIGURE 111.65–40(f) (5) (iii)-Typical elementary wiring diagram and arrangement plan of gravity davit and boat winch employing power limit switches and combined starter and main line emergency disconnect switches in accordance with Subpart 160.015, Subchapter Q.