Grounding_and_bonding_checks.pdf

MIL-HDBK-419A

GROUNDING, BONDING, SHIELDING

Evaluation Station Date

1. Is the resistance to earth of the earth electrode subsystem less than 10 ohms?

MIL-STD-188-124A, 5.1.1.1.3.1

2. Are the lightning down conductors continuous and welded or brazed to the earth electrode subsystem?

MIL-STD-188-124A, 5.1.1.1.5

3. Are underground metal pipes entering the facility bonded to the earth electrode subsystem?

MIL-STD-188-124A, 5.1.1.1.6

4. a. Was the fall-of-potential method used to measure the earth electrode subsystem?

b. Is the data available for inspection?

MIL-STD-188-124A, 5.1.1.1.7

5. a. Is there a separate grounding conductor (green wire) for the power system?

b. Is it installed with phase and neutral conductors?

MIL-STD-188-124A, 5.1.1.2.1

c. Is conduit used in lieu of the separate grounding conductor?

MIL-STD-188-124A, 5.1.1.2.5.1

6. Are all non-current carrying metal objects grounded?

MIL-STD-188-124A, 5.1.1.2.1

7. Are all main metallic structural members electrically continuous and grounded?

MIL-STD-188-124A, 5.1.1.2.2

8. Are all metallic piping, tubing and supports electrically continuous and grounded?

MIL-STD-188-124A, 5.1.1.2.3

9. Are all electrical supporting structures electrically continuous and grounded?

MIL-STD-188-124A, 5.1.1.2.4

10. a. Is the ac neutral grounded only at the service entrance to the earth electrode subsystem?

b. Is there ac current on the green wire or on the signal reference network?

MIL-STD-188-124A, 5.1.1.2.5; NEC 250-23

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YES NO

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20.

a. Are all generators grounded?

b. Are the frames of the generators grounded?

c. Are the neutrals of the generators tied together and grounded by a single lead to the earth electrode subsystem?

MIL-STD-188-124A, 5.1.1.2.5.2; NEC 250-26

Are the ground terminals of all ac outlets connected to the facility ground system through the grounding (green) conductor?

MIL-STD-188-124A, 5.1.1.2.5.3

a. Is one leg of each dc power system grounded?

b. At one point only, i.e, source or load?

MIL-STD-188-124A, 5.1.1.2.5.5

a. Is the facility protected against lightning?

b. Are all antennas inside a 1:1 cone of protection?

MIL-STD-188-124A, 5.1.1.3.2

Do any down conductors of the lightning protection subsystem have bends with a radius less than 20 cm (8 inches) or bends not less than 90°?

MIL-STD-188-124A, 5.1.1.3.3

Are all metal objects within 1.8 meters (6 ft) of the lightning down lead bonded to the down conductor or grounded to the facility ground?

MIL-STD-188-124A, 5.1.1.3.3

Are all bonds between elements of the lightning protection subsystem welded or brazed or secured by UL-approved clamps?

MIL-STD-188-124A, 5.1.1.3.4

a. Does the tower have an earth electrode subsystem?

b. Is it connected to the earth electrode subsystem of the building7

MIL-STD-188-124A, 5.1.1.3.8.1

a. Are the down conductors from the tower bonded to the tower at the base?

b. Are the down conductors run through metal conduit?

c. If yes, is the conductor bonded to the conduit at each end?

MIL-STD-188-124A, 5.1.1.3.8.3 and 5.1.1.3.7

Is the waveguide grounded (1) near the antenna (2) at the vertical to horizontal transition and (3) at the waveguide entry port?

MIL-STD-188-124A, 5.1.1.3.8.4

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Are all hand rails, ladders, stairways, antenna pedestals, and other objects subject to human contact grounded?

MIL-STD-188-124A, 5.1.1.3.9

22. Are power lines at the point of entry to the facility protected with approved lightning arresters?

MIL-STD-188-124A, 5.1.1.3.12

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24.

25.

26.

Are overall cable shields grounded at each end?

MIL-STD-188-124A, 5.1.2.1.1.4

Do any bonds show any signs of corrosion?

MIL-STD-188-124A, 5.2.3.1

Are all bolted or threaded fastener bonds adequately torqued?

MIL-STD-188-124A, 5.2.3.3 and 5.2.6.5; Table 1-23

Do any bonds have high resistance across the bond?

MIL-STD-188-124A, 5.2.4

27.

28.

Is soft solder used for bonds subject to lightning or power fault currents?

MIL-STD-188-124A, 5.2.6.4

Are C-clamps or spring clamps used for bonding?

MIL-STD-188-124A, 5.2.6.6

29. Are bonded areas visually clean?

MIL-STD-188-124A, 5.2.8

30. Is each subassembly and chassis adequately bonded to the rack, frame, or cabinet?

MIL-STD-188-124A, 5.2.10

31.

32.

Are cable connectors adequately mounted?

MIL-STD-188-124A, 5.2.11

a. Are shields of coaxial cable adequately fastened?

b. Are shield pigtails less than 2.5 cm (1 inch) long?

MIL-STD-188-124A, 5.2.12

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33. a. Do shielded enclosures appear to retain their integrity?

b. Do grounding conductors cross shielded enclosure without being bonded to enclosure?

MIL-STD-188-124A, 5.3.1

34. In the routing and layout of wire, are power lines and high level signal lines kept separate from low level signal lines?

MIL-STD-188-124A, 5.3.2.5

35. Is there a need for a Lower Frequency Network?

MIL-STD-188-124A, 5.1.1.4.3

36. Is there a need for a Higher Frequency Network?

MIL-STD-188-124A, 5.1.1.4.2

37. Is a Lower Frequency Network installed?

MIL-STD-188-124A, 5.1.1.4.3

38. Is a Higher Frequency Network installed?

MIL-STD-188-124A, 5.1.1.4.2

39. Is the equipotential plane bonded to the facility ground earth electrode subsystem?

MIL-STD-188-124A, 5.1.1.4.2

40. Have any resistance measurements been conducted on the equipotential plane?

MIL-STD-188-124A, 5.1.2.1.1

41. Are ground-fault-circuit-interrupters (GFCI) installed on 15 and 20 AMP convenience outlets?

MIL-STD-188-124A, 5.1.1.2.5.7 and 5.1.2.2.2

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