standards and guidelines for communication sites - Radio And ...

standards and guidelines for communication sites - Radio And ... standards and guidelines for communication sites - Radio And ...

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24.12.2012 Views

GROUNDING (EARTHING) FOR DISPATCH CENTERS AND NETWORK OPERATOR POSITIONS CHAPTER 5: INTERNAL GROUNDING (EARTHING) Surge protection devices should be present on all AC power, telephone and data communication cables at every network operator position or cluster to help minimize voltages between communication conductors and conductive surfaces (see Chapter 7, “Surge Protective Devices”). When SPDs are present, they shall be bonded to the SSGB using conductors as follows: • 6 mm 2 csa (#10 AWG) insulated copper conductor for lengths not exceeding 914 mm (3 ft.). • 16 mm2 csa (#6 AWG) insulated copper conductor for lengths not exceeding 3.9 m (13 ft.). The grounding conductors shall be run using the shortest, most direct route as practicable. See Figure 5-39 for a high level overview of the required bonding. Drop Ceiling Grid System and Ancillary Items within Dispatch Area Bonding Grid in Dispatch Room Main SSGB or MGB for Dispatch Room Raised Flooring Pedestal by Operator Position or Cluster SSGB at Each Operator Position or Cluster of Positions Operator Furniture Bonding Terminal (if provided) FIGURE 5-39 EXAMPLE OF NETWORK OPERATOR POSITION GROUNDING Voice / Data Secondary SPDs 5.8.3.2 INTERPOSITION BONDING FOR MULTI-CLUSTER NETWORK OPERATOR POSITIONS When a dispatch room is configured with multiple network operator position clusters, consideration should be given to establishing a bonding grid that interconnects all network operator position SSGBs and equalizes potentials among the clusters. This bonding grid will be of value if an operator of one cluster, while still connected to his or her own position, approaches a position in an adjacent neighboring cluster. When a bonding grid is installed it shall meet the requirements of this paragraph. See Figure 5-40 and Figure 5-41 on page 5-67 for examples. 5-66 68P81089E50-B 9/1/05 Type-3 SPD Branch Circuit Outlet Box Voice Data ACEG Provided in AC Supply Cords Video Display Processor/ Controller Headset Interface

STANDARDS AND GUIDELINES FOR COMMUNICATION SITES GROUNDING (EARTHING) FOR DISPATCH CENTERS AND NETWORK OPERATOR POSITIONS . Door Frame Air Handling Ducts Electrical Panelboard Sub Floor Piping System Drop Ceiling Grid Exposed Support Beam or Column Main SSGB or MGB for Dispatch Room Operator Cluster SSGB Operator Cluster FIGURE 5-40 RAISED FLOORING GROUNDING GRID, SHOWING BONDING OF ANCILLARY SUPPORT APPARATUS TO THE BONDING GRID Electrical Panelboard Operator Cluster SSGB Raised Flooring Pedestal Main SSGB or MGB for Dispatch Room FIGURE 5-41 RAISED FLOOR GROUNDING GRID AND NETWORK OPERATOR EQUIPMENT GROUND BUS SYSTEM 68P81089E50-B 9/1/05 5-67 Operator Cluster

GROUNDING (EARTHING) FOR DISPATCH CENTERS AND NETWORK OPERATOR POSITIONS CHAPTER 5: INTERNAL GROUNDING (EARTHING)<br />

Surge protection devices should be present on all AC power, telephone <strong>and</strong> data <strong>communication</strong> cables<br />

at every network operator position or cluster to help minimize voltages between <strong>communication</strong><br />

conductors <strong>and</strong> conductive surfaces (see Chapter 7, “Surge Protective Devices”). When SPDs are<br />

present, they shall be bonded to the SSGB using conductors as follows:<br />

• 6 mm 2 csa (#10 AWG) insulated copper conductor <strong>for</strong> lengths not exceeding 914 mm (3 ft.).<br />

• 16 mm2 csa (#6 AWG) insulated copper conductor <strong>for</strong> lengths not exceeding 3.9 m (13 ft.).<br />

The grounding conductors shall be run using the shortest, most direct route as practicable.<br />

See Figure 5-39 <strong>for</strong> a high level overview of the required bonding.<br />

Drop Ceiling Grid System<br />

<strong>and</strong> Ancillary Items within<br />

Dispatch Area<br />

Bonding Grid in<br />

Dispatch Room<br />

Main SSGB or<br />

MGB <strong>for</strong><br />

Dispatch Room<br />

Raised Flooring Pedestal by<br />

Operator Position or Cluster<br />

SSGB at Each<br />

Operator Position or Cluster<br />

of Positions<br />

Operator<br />

Furniture<br />

Bonding Terminal<br />

(if provided)<br />

FIGURE 5-39 EXAMPLE OF NETWORK OPERATOR POSITION GROUNDING<br />

Voice / Data<br />

Secondary SPDs<br />

5.8.3.2 INTERPOSITION BONDING FOR MULTI-CLUSTER NETWORK OPERATOR POSITIONS<br />

When a dispatch room is configured with multiple network operator position clusters, consideration<br />

should be given to establishing a bonding grid that interconnects all network operator position SSGBs<br />

<strong>and</strong> equalizes potentials among the clusters. This bonding grid will be of value if an operator of one<br />

cluster, while still connected to his or her own position, approaches a position in an adjacent<br />

neighboring cluster. When a bonding grid is installed it shall meet the requirements of this paragraph.<br />

See Figure 5-40 <strong>and</strong> Figure 5-41 on page 5-67 <strong>for</strong> examples.<br />

5-66 68P81089E50-B 9/1/05<br />

Type-3<br />

SPD<br />

Branch Circuit<br />

Outlet Box<br />

Voice<br />

Data<br />

ACEG Provided in AC<br />

Supply Cords<br />

Video<br />

Display<br />

Processor/<br />

Controller<br />

Headset<br />

Interface

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