1.1 The purpose of this specification is to provide details of an enclosure that protects internal equipment from rain, dust, vandalism and other conditions found in an outdoor or otherwise harsh environment.
1.2 The manufacturer must be able, upon request, to produce part numbers on all components for repair purposes. Certificates of compliance may be requested on each cabinet or on any component or part thereof.
2.1 The enclosure(s) will meet or exceed the requirements of a NEMA rating (Specify either 3R or 4X) and shall be U.L listed.
3.0 CABINET CONSTRUCTION
3.1.1 The cabinet and door(s) shall be constructed from 5052-H32 sheet aluminum alloy which has a thickness of .125 inch. Alternate material is type 304 stainless steel, minimum thickness 14 gauge. (Specifier must choose either aluminum or stainless steel construction.) External welds shall be made by using the Heliarc welding method; whereas, internal welds will be made by the wire welding method. All welds shall be neatly formed and free of cracks, blow holes and other irregularities.
3.1.2 All inside and outside edges of the cabinet shall be free of burrs.
3.1.3 The cabinet shall be designed with a sloped top be prevent the accumulation of water on its top surface.
3.1.4 The door opening shall be double flanged on all (4) sides which increases strength around openings and keeps dirt and liquids from entering the enclosure when door is opened.
3.1.5 A door restraint shall be provided to prevent door movement in windy conditions.
3.2.1 The cabinet door will be a minimum of 80% of the front surface area and shall be hinged on the right side when facing the cabinet.
A. The door shall be furnished with a gasket that satisfies the physical properties as found in UL508 table 21.1 and shall form a weathertight seal between the cabinet and door.
3.2.2 The hinges shall be continuous and bolted to the cabinet and door utilizing 1/4-20 stainless steel carriage bolts and nylock nuts.
A. The hinge will be made of .075 inch thick stainless steel and shall have .250 inch diameter stainless steel hinge pin.
B. The hinge pin shall be capped top and bottom by weld to render it tamperproof.
C. Hinge leaves will not be exposed externally when the door is closed, but hinge knuckles may protrude. Note: On NEMA Type 4X enclosures, all bolt holes shall be gasketed.
3.2.3 The latching mechanism shall be a 3-point draw roller type.
A. Pushrods will be turned edgewise at the outwards supports and shall be .250 inch by .750 inch aluminum, minimum.
B. Rollers shall have a minimum diameter of .875 inch and will be made of nylon. The center catch shall be fabricated from .187 aluminum, minimum.
3.2.4 An operating handle shall be furnished.
A. The handle will be stainless steel with a 3/4 inch diameter shank.
B. The latching handle shall have a provision for padlocking in the closed position.
C. (3R only) The lock shall be keyed dead bolt Corbin Lock or equivalent. Two (2) keys will be furnished with each lock. Note: On NEMA Type 4X enclosures, the specified Corbin Lock is deleted. These are available only with padlocking on the latching handle.
3.2.5 A light/alarm switch bracket shall be provided.
3.3 SWITCH COMPARTMENT
3.3.1 A switch compartment, with removable back panel, is supplied on the enclosure main door. 3.3.2 The switch compartment door opening shall be double flanged on all four (4) sides for strength and to prevent liquids or dirt from dropping into the compartment when the door is open.
A. The door shall be furnished with a gasket that satisfies the physical properties as found in UL508 Table 21.1 and will form a weathertight seal between the cabinet and door.
3.3.3 (3R only) The switch compartment door lock is a keyed slam latch or equal, and has a keyhole cover. Note: On NEMA Type 4X enclosures, the specified Corbin Lock is replaced with a weathertigh key lock.
3.3.4 The switch compartment door hinge is .063 inch stainless steel with a .120 diameter stainless steel hinge pin (hidden hinges).
4.0 CABINET VENTILATION
(NEMA 3R Only)
4.1 A cabinet requiring ventilation shall be provided with louvered vents in the front door with a removable air filter.
4.1.1 Louvers shall satisfy the NEMA rod entry test for 3R ventilated enclosures.
4.1.2 The filter will cover the vents and shall be held firmly in place with bottom and top brackets and springloaded clamps.
4.1.3 Exhaust air will be vented out between the top of the cabinet and door.
A. The exhaust area shall be a series of .120 x 1.0 inch rectangular holes.
4.1.4 The ventilation plenum area shall be equipped with a removable plate with provisions for mounting an optional fan assembly. Note: On NEMA Type 4X enclosures, all louver air intake vents on the door and air exhaust in the roof overhang are deleted.
4.2 The ventilation system will be designed to handle a minimum of 100 cubic feet of air per minute.
5.0 EQUIPMENT MOUNTING
(Specify as required)
5.1 ADJUSTABLE CHANNELS
5.1.1 The enclosure shall be equipped with two (2) adjustable "C" mounting channels on both side walls and back wall of the enclosure, allowing versatile positioning of shelves or panels.
5.1.2 The mounting channels shall provide infinite vertical and horizontal adjustment and not limit the positioning of shelves or panels. All mounting hardware will be furnished (See mounting channel detail).
5.2.1 If equipment is to be shelf mounted, the enclosure shall be provided with shelves
fabricated from 5052-H32 aluminum having a thickness of .125 inch.
5.2.2 The shelf depth shall be a minimum of 10.500 inches. The enclosure will have provision for positioning shelves or panels to within four (4) inches of the bottom and to within eight (8) inches of the top of the enclosure.
5.3 ALUMINUM BACK PANEL
5.3.1 If the equipment is to be panel mounted, the enclosure shall be provided with a
5052-H32 aluminum back panel having a thickness of .125 inch.
6.0 CABINET FINISH
6.1 Unless otherwise specified, the outside of the cabinet shall have a smooth, uniform, natural aluminum finish.
6.2 If painted, the following steps shall be taken as a minimum requirement.
6.2.1 The cabinet doors and any other parts to be painted will be treated with an iron phosphate conversion technique.
6.2.2 After phosphatizing, the parts shall be baked to eliminate any moisture in seams.
6.2.3 The finish coat of a Polyester Powder will be baked ten (10) minutes at 400- 450 degrees F.
6.2.4 The finish shall be commercially smooth, substantially free of flow lines, paint washout, streaks, blisters and other defects that would impair serviceability or detract from general appearance.
7.0 CABINET MOUNTING
(Specify as required)
7.1 POLE OR WALL MOUNTED ENCLOSURE
7.1.1 Enclosures intended for pole or wall mounting shall be provided with stiffener plates with a thickness of .125 inch aluminum welded to top and bottom of rear wall for added strength and rigidity. Note: On NEMA Type 4X enclosures,
all mounting holes must be gasketed.
7.2 PEDESTAL MOUNTED ENCLOSURE
7.2.1 Enclosures intended for pedestal mounting shall be provided with a reinforced base plate. If the enclosure is fabricated from .125 inch thick aluminum, the base plate will be a thickness of .250 inch aluminum. Note: On NEMA Type 4X enclosures, all mounting holes must be gasketed.
7.3 PAD MOUNTED ENCLOSURE
7.3.1 Enclosures intended for pad mounting shall be constructed with the following patterns: Note: for NEMA Type 4X ratings, a solid plate will be in place on the bottom of the enclosure to provide a weathertight seal.
8.0 APPROVED MANUFACTURER
8.1 Cabinet is to be manufactured by APX Enclosures, Inc. or an approved U.L. listed equivalent.