Code of Federal Regulations Title 7. Agriculture 7 CFR § 1755.522, App. D Appendix D to 7 CFR 1755.522—Acceptance Checklist—Single-point Grounding System

1. Approval Statement

Telephone Company:

RUS Borrower Designation:

RUS Contract Number:

N/A

Name:

Central Office:

Remote:

Date of Inspection:

Names of Inspectors:

Owner Representative

Central Office Supplies

Consulting Engineer

Mutually Approved Exceptions:

Grounding System Approval:

Name (Owner Representative)

Signature

Title

Date

Name (Supplier Representative)

Signature

Title

Date

2. General Survey

2.1 This office is considered to be in the following category for probability of lightning damage based on the Figure 1 map in RUS TE&CM 823 (also refer to paragraph (u)(2) of § 1755.522)

__Very High __Higher than Average __ Average __Lower than Average __Very low

2.2 Central office ground field (COGF) to be inspected for proper bonding of conductors to ground rods, etc. COGF to earth grounding reading is ____ohms. (Refer to RUS TE&CM 802, Appendices C and D, Measurement Techniques.) Is this resistance reading acceptable? (Refer to RUS TE&CM 810, Items 1.6, 4.6.2 and 4.6.3 for protection considerations.)

Acceptable: __Yes __No

Comments:

2.3 Ground connection to be inspected from the master ground bar (MGB) to the central office ground field (COGF) to ensure it is properly sized and installed by most direct route with no sharp bends. (Refer to RUS TE&CM 810, Item 4.3.2 and section 8.1.)

Acceptable: __Yes __No

Comments:

2.4 Building structure grounds (steel rebar in footings, ironwork, etc.) are to be properly bonded and connected to the MGB. (Refer to RUS TE&CM 810, Item 4.3.4.)

Acceptable: __Yes __No

Comments:

2.5 Metallic central office door(s) are to be painted with metallic paint with doorknobs left bare. Door(s) and frames are to be grounded to the building structural ground or the MGB.

Acceptable: __Yes __No

Comments:

2.6 Metallic fences within 6 feet (183 cm) of the exchange building, storage facilities ground field, etc. are to be properly bonded to the COGF outside of the central office building. Handhole enclosure is to be used for the COGF connection to permit inspection and disconnect for earth resistance testing. (Refer to RUS TE&CM 810, Appendix C, Item 4.6.1.)

Acceptable: __Yes __No

Comments:

2.7 Lightning rod systems are to be grounded by a separate dedicated ground field. A bond should be provided between the COGF and the lightning rod ground field. Handhole enclosure is to be used for the COGF connection to permit inspection and disconnect for earth resistance testing. (Refer to RUS TE&CM 810, Item 4.3.2.1.)

Acceptable: __Yes __No

Comments:

2.8 Radio/microwave tower ground grid is to be properly bonded to the COGF by a direct outside connection. Handhole enclosure is to be used for the COGF connection to permit inspection and disconnect for earth resistance testing. (Refer to RUS TE&CM 810, Item 4.3.2 and section 10.)

Acceptable: __ Yes __ No

Comments:

2.9 If a qualified metallic water system is present, inspect the MGB connecting conductor to ensure that it is properly sized and installed by the most direct route with no sharp bends and that it is clamped solidly on the water pipes. (Refer to RUS TE&CM 810, Item 4.3.3 for details on metallic water system grounding.)

Acceptable: __ Yes __ No

Comments:

2.10 All power and grounding conductors are to be continuous, end to end, with no splices, size discontinuity or intermediate terminations. If an exception is necessary, unusual care must be taken to assure proper bonding between the two sections. (Refer to RUS TE&CM 810, Appendix C, section 5.)

Acceptable: __ Yes __ No

Comments:

2.11 All ground conductors should be void of sharp bends along their entire lengths. (Refer to RUS TE&CM 810, Item 8.2.2.)

Acceptable: __ Yes __ No

Comments:

2.12 Ground conductors should only be placed in nonmetallic conduit. Those routed through metallic conduit require that both ends of the conduit be bonded to the ground conductor. (Refer to RUS TE&CM 810, Item 8.2.4.)

Acceptable: __ Yes __ No

Comments:

2.13 Ground conductors should not be encircled by metallic clamp. Metallic straps are to be removed and replaced with nonmetallic clamps. (Refer to RUS TE&CM 810, Item 8.2.4.)

Acceptable: __ Yes __ No

Comments:

2.14 If metallic conduit is used, it is to be insulated from all ironwork.

Acceptable: __ Yes __ No

Comments:

2.15 Inspect to determine if the required central office supplier electrostatic discharge plates, wrist wraps, antistatic floor mats, etc. are available and properly installed. (Refer to RUS TE&CM 810, Item 12.3.)

Acceptable: __ Yes __ No

Comments:

2.16 Ground conductors, except green wires, should not be routed close and parallel to other conductors so as to minimize induction on surges into equipment wiring. It is also better not to route these ground conductors through cable racks or troughs, or within the confines of any iron work. (Refer to RUS TE&CM 810, Item 8.2.3.)

Acceptable: __ Yes __ No

Comments:

3. Master Ground Bar (MGB)

3.1 The designated P, A, N, and I segments of the master ground bar (MGB) should be clearly identified. (Refer to RUS TE&CM 810, Figure 1 for MGB segmentation arrangement.)

Acceptable: __Yes __No

Comments:

3.2 Check for appearance and proper location of following on MGB:

(a) R—Interior radio equipment  1

 Surge Producer—(P)

(b) C—Cable entrance ground bar  1

 Surge Producer—(P)

(c) M—MDF ground bar  1

 Surge Producer—(P)

(d) G—Standby power equipment frame ground  1

 Surge Producer—(P)

(e) N—Commercial power MGN  2

 Surge Absorber—(A)

(f) B—Building structure ground  2

 Surge Absorber—(A)

(g) L—Central office ground field  2

 Surge Absorber—(A)

(h) W—Water pipe system  2

 Surge Absorber—(A)

(i) N  1—Battery Return  3

 Surge Producer—(P)

 Grounds to non-IGZ Equipment—(N)

(j) N  2—Outside IGZ: ______ 3

 Surge Absorber—(A)

 Grounds to non-IGZ Equipment—(N)

(k) N  3—Outside IGZ: ______ 3

 Grounds to non-IGZ Equipment—(N)

(l) I  1—Ground window bar  4

 Surge Producer—(P)

 Grounds to IGZ Equipment (GWB's)—(I)

(m) I  2—Ground window bar  4

 Surge Absorber—(A)

 Grounds to IGZ Equipment (GWB's)—(I)

Acceptable: __Yes __No

Comments:

3.3 All connections to MGB are to be two-hole bolted down copper crimped or compression type terminal lugs. (NOTE:  No solder connections are permitted.)

Acceptable: __Yes __No

Comments:

3.4 MGB is to be properly insulated from the mounting surface.

Acceptable: __Yes __No

Comments:

3.5 All connections are to be tight.

Acceptable: __Yes __No

Comments:

3.6 The MGB is to have an anticorrosion coating of the type which enhances conductivity.

Acceptable: __Yes __No

Comments:

3.7 Bar is to be clearly stenciled or legibly labeled “MGB.”

Acceptable: __Yes __No

Comments:

3.8 All ground leads are to be properly sized and labeled as to point of origin. (Refer to RUS TE&CM 810, Item 8.3.1 and section 8.1.)

Acceptable:  __Yes __No

Comments:

4. Ground Window Bar (GWB)

4.1 All equipment grounds that originate inside of an Isolated Ground Zone (IGZ) are to be terminated on the GWB which is preferably located physically inside the IGZ and insulated from its support. (Refer to RUS TE&CM 810, Item 5.1.)

Acceptable:  __Yes __No

Comments:

4.2 Each GWB is to be connected to the MGB by the most direct route with a conductor of 2/0-gauge or coarser, or resistance of less than 0.005 ohms. Parallel conductors for redundancy if required by the supplier. (Refer to RUS TE&CM 810, Item 8.1.2.)

Acceptable:  __Yes __No

Comments:

4.3 The metal framework grounds of only that switching equipment and associated electrical equipment located inside of the IGZ should be connected to the GWB as required by the central office equipment supplier. (Refer to RUS TE&CM 810, Item 5.5.)

Acceptable:  __Yes __No

Comments:

4.4 GWB is to be clearly stenciled or labeled “GWB.”

Acceptable:  __Yes __No

Comments:

4.5 All connections are to be tight.

Acceptable:  __Yes __No

Comments:

5. Isolated Ground Zone (IGZ)

5.1 IGZ areas are to be clearly marked on the floor or in some other easily recognizable manner. (Refer to RUS TE&CM 810, Item 6.1.1)

Acceptable:  __Yes __No

Comments:

5.2 Confirm that all framework, cabinets, etc., within the IGZ are ground connected only to the GWB. (Refer to RUS TE&CM 810, Item 5.5.)

Acceptable:  __Yes __No

Comments:

5.3 All cable racks, ground mats, switching and transmission equipment within the IGZ are to have ground leads only to the GWB. (Refer to RUS TE&CM 810, Item 5.5.2.)

Acceptable:  __Yes __No

Comments:

5.4 Review ac power feed arrangement within the IGZ for acceptable receptacle type and confirm that all green wires are properly connected. (Refer to RUS TE&CM 810, Item 5.5.4.)

Acceptable:  __Yes __No

Comments:

5.5 All ironwork, metallic conduit, and other equipment associated with the switch are to be properly insulated at the IGZ boundary as stipulated by the supplier. (Refer to RUS TE&CM 810, Item 6.2.)

Acceptable:  __Yes __No

Comments:

5.6 With the GWB disconnected from the MGB, the resistance reading of ___ ohms between the GWB and the MGB indicates adequate isolation. (CAUTION:  Test is to be conducted only with the approval and under the direction of the central office supplier.)

Acceptable:  __Yes __No

Comments:

6. Entrance and Tip Cables

6.1 When neither a cable vault nor a splicing trough exists, the outside plant cable should be brought into the central office and spliced to tip cables with a PVC outer jacket (ALVYN^R) or equivalent as close as practical to the cable entrance. (Refer to RUS TE&CM 810, Item 7.3.4.)

Acceptable:  __Yes __No

Comments:

6.2 All outside entrance cables and all tip cable shields are to be separated by at least a 3–inch (7.6 cm) gap between shield ends.

Acceptable:  __Yes __No

Comments:

6.3 All entrance cable shields are to be bonded separately to #6 AWG or larger insulated wire or bonding ribbon and connected to the Cable Entrance Ground Bar (CEGB) by most direct route with minimum bends.

Acceptable:  __Yes __No

Comments:

6.4 Outside plant cable shields are to be connected only to the CEGB, and the tip cable shields are to be connected only to the Main Distributing Frame Bar (MDFB).

Acceptable:  __Yes __No

Comments:

7. Cable Entrance Ground Bar (CEGB)

7.1 The CEGB is to be properly insulated from the mounting surface. (Refer to TE&CM 810, Item 4.2.1.)

Acceptable:  __Yes __No

Comments:

7.2 The CEGB is to be located as close as possible to the physical ends of the entrance cable shields.

Acceptable: __Yes __No

Comments:

7.3 All connections are to use two-hole bolted down copper crimped or compression type terminal lugs. (NOTE:  No solder connections are permitted.)

Acceptable: __Yes __No

Comments:

7.4 All connections are to be tight.

Acceptable: __Yes __No

Comments:

7.5 Bar is to be clearly stenciled or legibly labeled “CEGB.”

Acceptable: __Yes __No

Comments:

7.6 All ground leads are to be properly sized and labeled.

Acceptable: __Yes __No

Comments:

7.7 The CEGB is to have an anticorrosion coating of the type which enhances conductivity.

Acceptable: __Yes __No

Comments:

7.8 The CEGB is to be connected to the MGB by a properly sized conductor and by the most direct route. (Refer to RUS TE&CM 810, section 8.1.)

Acceptable: __Yes __No

Comments:

8. Main Distributing Frame (MDF)

8.1 RUS strongly recommends that MDF protectors be furnished without heat coils. (Refer to RUS TE&CM 810, section 7.6.)

Acceptable: __Yes __No

Comments:

8.2 Incoming cable pairs terminated on MDF protector assemblies should be protected with protector modules. These modules should contain white coded carbon blocks or orange coded gas tube arrestors that are included in the RUS List of Materials. (Refer to RUS TE&CM 810, Item 7.4)

Acceptable: __Yes __No

Comments:

8.3 All incoming subscriber cable pairs are to be properly terminated at either a protector equipped terminal or connected to ground.

Acceptable:  __Yes __No

Comments:

8.4 MDF protector assemblies may be mounted directly on the vertical frame ironwork. Protector assemblies on each vertical are interconnected with each other and the Main Distributing Frame Bar (MDFB) with a #6 copper grounding conductor. Alternative means of connecting to the MDFB are also acceptable which do not rely on the frame ironwork for conducting surge currents to ground. (Refer to RUS TE&CM 810, section 7.)

Acceptable:  __Yes __No

Comments:

8.5 Protective “ground connections” should be provided between the MDFB and the frame ironwork for personnel protection regardless of the type of protector assembly used. Protective ground leads should be 14–gauge, less than 12 inches (30.5 cm) in length with paint thoroughly removed at point of connection to the ironwork. (Refer to RUS TE&CM 810, Item 7.1.3.)

Acceptable:  __Yes __No

Comments:

8.6 The MDFB should be insulated from the frame ironwork in all cases where it is used as a Master Ground Bar (MGB). (Refer to RUS TE&CM 810, Item 7.1.2.)

Acceptable:  __Yes __No

Comments:

8.7 Where the MDFB is used as the MGB in very small offices the protective “ground connections” should be connected on the N section of the bar. The MDF line protector assembly grounds should be connected to the P section of the bar. (Refer to RUS TE&CM 810, Item 7.1.4.)

Acceptable:  __Yes __No

Comments:

8.8 The MDFB is to be connected to the MGB by the most direct path with minimum bends and proper conductor size. (Refer to RUS TE&CM 810, Item 8.1.4.)

Acceptable:  __Yes __No

Comments:

8.9 The MDFB should be free of all other ground leads when not used as an MGB.

Acceptable:  __Yes __No

Comments:

8.10 Alternative arrangements which insulate the line protector assemblies and MDFB from the frame ironwork may require a direct ground connection of the frame ironwork to the MGB for personnel protection. Conductor is properly sized and tightened with paint removal on main frame ironwork at point of connection.

Acceptable:  __Yes __No

Comments:

9. Power Service Protection and Grounding

9.1 The ground conductor between the ac power system multigrounded neutral (MGN) at the main ac disconnect panel and the master ground bar (MGB) is to be properly sized and connected. (Refer to RUS TE&CM 810, Items 2.19, 4.3.1 and 8.1.3.)

Acceptable: __Yes __No

Comments:

9.2 If there is a non-MGN ac power system, there is to be a properly sized and connected insulated conductor bond between the power service ground electrode and the MGB. (Refer to RUS TE&CM 810, Item 4.3.1.1.)

Acceptable: __Yes __No

Comments:

9.3 AC conductors including ground conductors serving 120–volt ac electric convenience receptacles and all direct wire peripheral equipment, located in the IGZ, should be sized in accordance with normal “green wire” criteria. (Refer to RUS TE&CM 810, Items 5.5.4, 5.5.5, and 5.5.6.)

Acceptable: __Yes __No

Comments:

9.4 Minimum protection for ac power serving the central office buildings should consist of an RUS accepted secondary arrestor at the service entrance. (Refer to RUS TE&CM 810, section 9.)

Acceptable: __Yes __No

Comments:

9.5 A properly sized conductor for ground bonding between the standby power plant framework (not separately derived) and the MGB is to be provided to equalize framework voltages for personnel safety reasons. (Refer to RUS TE&CM 810, Item 4.2.4.)

Acceptable: __Yes __No

Comments:

10. Miscellaneous

10.1 All non-IGZ equipment frames, relay racks, cable racks and other ironwork are to be properly connected to the MGB. (Refer to TE&CM 810, Item 4.4.)

Acceptable: __Yes __No

Comments:

10.2 Shields on high frequency intra-office cables are to be properly isolated and connected only to an isolation ground bar in the relay rack. All shielded cables entering the IGZ should only be referenced at the IGZ termination point as given by the manufacturer. (Refer to RUS TE&CM 810, Item 7.2.1.2.)

Acceptable: __Yes __No

Comments:

10.3 Isolation ground bars in the relay racks are to be properly connected to the MGB with appropriate sized conductor with no sharp bends.

Acceptable: __Yes __No

Comments:

10.4 All radio equipment cabinet(s) are to be at least 10 feet (305 cm) from the IGZ.

Acceptable: __Yes __No

Comments:

10.5 The metal spare parts cabinet is to be grounded with a #6 AWG or larger insulated wire to non-IGZ cable rack, etc. or directly to the MGB.

Acceptable: __Yes __No

Comments: