MIL-DTL-16036M(SH)
3.17 Switchboard enclosures.
3.17.1 Rear enclosures. The rear of each unit shall be provided with a removable enclosure. These rear
enclosures shall be made of expanded metal (rolled flat), perforated sheet, or solid sheets. Rear enclosures shall be
sectionalized into not less than two horizontal parts to facilitate handling. When solid sheets are used, ventilation
openings shall be provided at the top and bottom with louvers or openings similar to those in expanded metal or
perforated sheet. Enclosures shall be adequately secured but shall not be used for structural strength. Openings in
expanded metal or perforated sheet shall not pass a rod having a diameter greater than 3/8 inch. Provision shall be
made for removal of fuses without removing the rear enclosure of a unit. On bench type of control units having
equipment mounted on the rear enclosures, the rear enclosures shall be a hinged, solid sheet. Clearances between
live bus work and disconnect devices, or both, and rear enclosures shall be adequate, in order to prevent these
nonstructural strength panels from coming into contact with live bus work, if the panels are buckled inward.
3.17.2 Top enclosure. The top of each section shall be enclosed by a sheet cover. The top shall prevent
dripping water or falling objects from entering the switchboard enclosure or damaging instruments on the front
panels. It shall extend approximately 4 inches out over the face of the front panels and 4 inches beyond the rear of
the switchboard structure or rear panel, if applicable. Clearance between the upper edge of the front panels and the
underside of the top sheet, where it extends over the front, shall be at least 1/4 inch. Front and rear edges of the top
sheet shall be turned up to form a l-inch flange along the entire length of the section or switchboard to prevent water
from spilling over the front or rear. To ensure watertight integrity at the corners, the turned-up front and rear flanges
shall be extended around the corners and along the end of the top sheet approximately 8 inches. The edge of the top
sheet shall be turned down to form a flange and shall overlap the side sheets of the switchboard to allow drainage
over the end in a manner that prevents water from seeping down the inside of the side sheet.
3.17.3 Panel fastening. Hinged and removable panels on the front and rear of the unit shall be secured by
3.17.4 Protection of enclosure from waterspray for submarine applications. When specified (see 6.2),
switchgear shall be protected on all sides from waterspray from any angle (see 4.4.3.6.1). Protection shall be
obtained by means of transparent, gasketed, quick opening covers mounted over circuit breaker handles, fuses,
meters, or other devices subject to water damage and by installing baffles (see figure 12) over louvers to exclude
waterspray. An operator s view of instruments and his ability to operate equipment shall not be impaired.
3.18 Guard rails. Each switchboard unit, except for distribution units, shall be provided with a vertical grab rod
located on the right-hand side, facing the unit (see figure 23). Rod shall be of smooth electrically insulated material
or hardwood supported with a sufficient number of brackets to provide adequate support for personnel under all
operating conditions of the ship. The rod shall be attached in such a manner that all panels can be removed and
hinged panels opened without removal of the rod from the member to which it is attached. These rods shall be
located so that they will not interfere with operation of the equipment and shall not extend more than 4 inches from
the front of the panel.
3.18.1 Removable guard rails. Removable guard rail sections shall be provided on the rear framework of the
switchboard when the rear enclosure is removed (see figure 24). In general, two horizontal rails shall be required at
proper levels to prevent personnel from being thrown against live buses caused by the motion of the ship. Rails shall
be made of smooth, electrically insulated material or hardwood. Rails shall be mounted on the inside of the rear
vertical members so as not to protrude beyond the rear or ends of the structure. Guard rail sections shall be easily
removable for maintenance access but shall be provided with securing bolts or other locking means to prevent
dislodgement caused by shock.
3.19 Painting and powder coating.
3.19.1 General. Exterior and interior surfaces of enclosures shall be painted or powder coated. The order of
operations shall be as follows:
a.
Complete fabricating operations such as welding, machining, drilling, and tapping.
b.
Remove rust and other visible corrosion products.
c.
Remove grease, oil, and dirt by solvent wiping, vapor degreasing, or caustic washing and rinsing.
42
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business