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 MIL-HDBK-419A
1.4.9 MIL-STD-188-124A and NEC Compliance Evaluation.
1.4.9.1 Measurements. This portion of the survey is performed to determine if the facility complies with the
requirements of the MIL-STD-188-124A as applicable to military installations in regard to grounding, bonding,
and shielding. Powerline and equipment grounding conductor current measurements, not related to the NEC,
are made at the time of the survey for convenience. Survey form contained in Section 2.2.2.4 Part IV is
provided. Guidance in making the current measurement is provided in Sections 2.3.2.4 and 2.3.3 Part IV.
Prepare sketches, as appropriate, that may aid in explaining the results of the survey or illustrating the
installation. Attach the sketches to the survey data.
a.
The verification required by some steps may involve more than an inspection. For example, in
verifying that all neutral conductors are color-coded white or natural gray, if a green colored wire is found
connected to the neutral bus it will be necessary to trace out the conductor to determine its proper function. If
the verification is not accomplished at the time of the inspection, the discrepancy should be recorded on the
data sheet and noted as a potential violation.
b.
During the inspection, it may be desirable to correct a deficiency at that time (e.g., cleaning a bond
area of paint). In such cases, record the discrepancy on the data sheet and note the corrective action taken.
MIL-STD-188-124A and NEC Compliance Inspection.
1.4.9.2
Note: Sections a(l), a(9), d(9), and d(15) are not MIL-STD-188-124A or NEC requirements but are for
information.
a.
Service entrance. Perform the following to determine that wiring at service entrances is in
accordance with MIL-STD-188-124A requirements.
(1) Determine if the input to the facility, from the power company, is single phase or three phase,
if three phase is delta or wye, and if one of the service conductors is identified (grounded). The identified
conductor will be the neutral.
(2) Verify that each run of cable, conduit, etc., contains all phases and the identified conductor
and that each identified conductor is grounded at or in the vicinity of and ahead of the service disconnecting
means. For example, if the source is a transformer whose secondary is a 3-phase, 4-wire wye with the neutral
grounded and the power is routed to the service disconnect switch through 3 conduits, each conduit must
contain all 3 phases and neutral, and the neutral must be grounded in the vicinity of the service disconnect
switch.
(3) For each building or service supplied by a single source, verify that the identified conductor is
routed to each service disconnect switch and that the conductor is connected to the earth electrode at each
building with a grounding electrode conductor that meets the requirements of Table 1-20.
(4) If the grounding electrode conductor is routed through a metallic enclosure (conduit, etc.),
verify that the enclosure is bonded to the conductor at both ends.
Note: It may not be possible to verify this connection at the electrode end as it may be inaccessible.
1-105
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