SPECIAL SPECIFICATION 1864 Pole Mounted Cabinet

Transcription

1 1993 Specifications CSJ s ,etc. & SPECIAL SPECIFICATION 1864 Pole Mounted Cabinet 1. Description. This specification describes the minimum acceptable requirements for a weatherproof cabinet and other specified accessory equipment as shown on the plans, as detailed in the Special Specifications, and as directed by the Engineer. 2. Cabinet. (1) General. This section of the specification describes the minimum acceptable design requirements for a weatherproof, pole mounted cabinet that will house wireless communication equipment and other specified accessory equipment. (2) Design Requirements. 1. The cabinet shall be of sheet aluminum with a minimum thickness of in., or cast aluminum alloy. The outside dimensions of the cabinet shall be 14 in. wide by 16 in. high by 10 in. deep with the door closed. All dimensions shall be ± 3 in. 2. The cabinet shall have a hinged door equipped with a gasket to insure a weatherproof and dustproof seal when the door is closed and locked. The door hinge shall be made of stainless steel, aluminum, or other non-rusting alloy. The hinge pin shall be made of stainless steel. The hinge pin shall be spot welded at the top of the hinge. 3. The cabinet shall be provided with 3-3/4 in. Myers hubs or exact equivalent. Two hubs shall be mounted on the top. The mounting position of the 2 top hubs shall be such that the 3/4 in. hole centers are 1.25 in. from the back of the cabinet. The top 2 holes shall also be positioned about the centerline that bisects the width of the cabinet. The spacing between the 2 holes shall be a minimum of 1.5 in. The third hub shall be provided for mounting on the bottom of the cabinet, however, the mounting hole shall not be cut. All hubs shall have a gasket and all mounted hub gasket seals shall be watertight. 4. The cabinet shall have 2-3/4 in. stainless steel brackets for trap type mounting on a wood or metal pole. Cabinets shall be shipped with the brackets mounted on the back of the cabinet. 5. The cabinet shall be provided with vent openings to allow adequate convection cooling of the electronic components. These vents shall be so located and designed to prevent the entry of water and screened to minimize the infiltration of dust and insects. Screen material shall have openings no larger than sq. in

2 6. The cabinet shall be completely weatherproofed to prevent the entry of water. All unwelded seams shall be sealed with a clear or aluminum colored weather-seal compound. 7. All exposed hardware including screws, bolts, rivets, hubs, etc., shall be tamper resistant. 8. Each cabinet, as a minimum, shall be supplied with the following: 1. Adjustable shelves, as required. 2. Backpanel. 3. Surge protection. 4. Terminal strips. 5. Interconnect harnesses with connectors. 6. Jack for field telephone. 7. Door Open connection to back panel. 8. All necessary installation and mounting hardware. (3) Electrical Requirements. (a) Backpanel. This panel shall include the following components: (i) Circuit Breakers. The circuit breakers shall be approved and listed by underwriters laboratories. The operating mechanism shall be enclosed and the switches shall be marked to indicate whether it is in the closed or open position. Contacts shall be silver alloy enclosed in an arc quenching chamber. Each cabinet shall have, as a minimum, a single pole, 20 ampere circuit breaker. Circuit breakers shall be unaffected by ambient temperature range, relative humidity, applied power, shock and vibration range specified in Section 2, Environmental Standards and Test Procedures, of NEMA TSL Circuit breakers shall have an interrupt capacity of 10,000 amperes and insulation resistance of 100 MEGS at 500 volts DC. (ii) Power Line Surge Protection. Power line surge protectors shall be provided and installed as described below. (A) One surge protector shall be a 3 electrode gas tube type and shall have the following ratings: 1. Impulse Breakdown. Less than 1,000 volts in less than 0.1 microseconds at 10 kilovolts/microsecond. 2. Standby Current. Less than 1 milliampere. 3. Striking Voltage. Limit any voltage greater than 212 volts DC. 4. Capable of withstanding 15 pulses of peak current, each of which will rise in 8 microseconds and fall in 20 microseconds to one half the peak voltage, at 3 minute intervals. Peak current rating

3 shall be 20,000 amperes. The surge protector shall utilize both metal oxide varistors and silicon avalanche diodes to protect against transients having a single surge energy level up to 70 joules, voltage transients up to 6 kv, and current transients up to 6 ka. Protection shall be provided for line to neutral, line to ground and neutral to ground terminals. (B) The protectors shall have the following ratings: 1. Recurrent peak voltage: 212 volts. 2. Energy rating minimum: 120 joules. 3. Power dissipation: average 0.85 watt ,000 amps peak current for pulses for less than 6 microseconds. 5. Standby current less than 1 milliampere. (iii) Power Cable Input Junction Terminals. Power distribution blocks suitable for use as a power feed and junction points for two 3-wire circuits shall be provided. The line side of each circuit shall permit termination of the conductors specified in the plans. The AC neutral and equipment ground wiring shall be electrically isolated from the line wiring by an insulation resistance of at least 10 megohms when measured at the AC neutral. The AC neutral and equipment grounding wiring shall be color coded white and green respectively. (iv) Voice Communication Jack. A RJ-11 modular telephone jack for the voice communication equipment shall be provided at a convenient location on the right side panel. The jack shall be connected to the communications medium. The back panel shall be utilized to distribute and properly interconnect all cabinet wiring related to the specific complement of equipment called out on the plans. Each item of equipment including any furnished by the Department shall have its cable harness properly terminated at terminal boards on the back panel. All functions available at the equipment connector shall be carried in the connector cable harness to the terminal blocks from the power distribution panel mounted on the left side panel of the cabinet. (b) Wiring. All cabinet wiring shall be identified by the use of insulated pre-printed sleeving slipped over the wire before attachment of the lug or making the connection. The wire markers shall carry this legend in plain words with sufficient details so that a translating sheet will not be required. All wires shall be cut to the proper length before assembly. No wires shall be doubled back to take up slack. Harnesses to connectors shall be covered with chinese finger woven braid or braided. Cables shall be secured with nylon cable clamps

4 Service loops shall be provided to facilitate removal and replacement of assemblies, panels and modules. All wiring containing line voltage AC shall be routed and bundled separately and/or shielded from all low voltage, i.e., control circuits. All conductors and live terminals or parts, which could be hazardous to maintenance personnel, shall be covered with suitable insulating material. All conductors used on the cabinet wiring shall be No. 22 AWG or larger with a minimum of 19 strands. Conductors shall conform to mil specification MIL-W , Type B or D. The insulation shall have a minimum thickness of 10 mils. All wiring containing line voltage shall be a minimum size of No. 14 AWG. (c) Terminal Strips. Terminal strips located on the backpanel shall be accessible to the extent that it shall not be necessary to remove the electronic equipment from the cabinet to make an inspection or connection. Terminal blocks shall be 2 position, multiple pole barrier type. Shorting bars shall be provided in each of the positions provided along with an integral marking strip. Terminal blocks shall be so arranged that they shall not upset the entrance, training and connection of incoming field conductors. All terminals shall be suitably identified by legends permanently affixed and attached to the terminal blocks. Not more than 3 conductors shall be brought to any 1 terminal screw. No electrically energized components or connectors shall extend beyond the protection afforded by the barriers. All terminal blocks shall be located below the shelves. Terminals used for field connections shall secure conductors by means of a No nickel or cadmium plated brass binder head screw. Terminals used for interwiring connections, but not for field connections, shall secure conductors by means of a No nickel plated brass binder head screw. As a minimum, all connections to and from the electronic equipment shall terminate to an interwiring type block. These blocks will act as intermediate connection points for all electronic equipment input/output. (d) Cabinet Internal Grounding. The cabinet internal ground shall consist of one or more ground bus-bars permanently affixed to the cabinet and connected to the grounding electrode. Bare stranded No. 6 AWG copper wire shall be used between bus-bars and between the bus-bar and grounding electrode. Each copper ground bus-bar shall have a minimum of 20 connector points, each capable of securing at least one number 10 AWG conductor. AC neutral and equipment ground wiring shall return to these bus-bars. (4) Surge Protection. Protector and Cabinet Configuration. All ungrounded conductor wires entering or leaving the cabinet shall be provided with surge protectors. The conductor leads and the surge protector leads shall be kept as short as possible with all conductor bends formed to the maximum possible radius. The protector units shall be located as near as possible (6 in.) to the entry or exit point, and as far as possible from any electrical equipment. The protector ground lead shall be connected directly to the ground bus

5 The surge protector utilized for AC power shall not dissipate any energy and shall not provide any series impedance during standby operation. The unit shall return to its nonshunting mode after the passage of any surge and shall not allow the shunting of AC power. (5) Environmental Design Requirements. The pole mounted cabinet shall meet all functional requirements during and after subjection to any combination of the following requirements: 1. Ambient temperature range of 0 F to 158 F. 2. Temperature shock not to exceed 30 F per hour, during which the relative humidity shall not exceed 95%. 3. Relative humidity range not to exceed 95% over the temperature range of 40 F to 110 F. 4. Moisture condensation on all surfaces caused by temperature changes. 3. Measurement. This Item will be measured as each unit furnished, installed, made fully operational and tested in accordance with these Special Specifications or as directed by the Engineer. 4. Payment. The work performed and materials furnished in accordance with this Item and measured as provided under Measurement will be paid for at the unit price bid for Pole Mounted Cabinet. This price shall include all equipment described under this Item with all cables and connectors, all documentation and testing; and shall include the cost of furnishing all labor, materials, training, warranty, equipment, and incidentals necessary to complete the work