Wireways, raceways, cable trays

Custom Search

Back
Power transfer and bypass switches

Up
Grounding, Bonding, and Shielding for Electronic Equipments and Facilities

Table 1-21. Equipment Grounding Conductor Size Requirement

MIL-HDBK-419A

(8) The equipment grounding conductor is a separate conductor, must be run in the same conduit

as the feeder, and should be wrapped around the insulated conductors.

(9) Using a clamp-on ammeter, measure the current in each input phase, the identified conductor,

and the equipment grounding conductor. Record the data on Part IV of the survey form in Chapter 2.

(10) Verify that bonds in the ac or dc power systems are not dependent upon solder for their

electrical and mechanical connections. Solder may be used only to supplement mechanical connections to lower

the overall impedance in RF/signal circuits or subsystems.

(11) Verify that all related phase and equipment grounding conductors ("safety grounds") to all

circuits supplied by the panel are routed through the same conduit, raceway, cable, etc.

(12) Verify that all separate equipment grounding conductors leaving the panel are green or green

with one or more yellow stripes or bare. If larger than No. 6 AWG and of another color, not white, they shall

be reidentified with paint, tape, tags, or other means at each end and at all places where the conductor is

accessible. Bare conductors should not be utilized where EMI or TEMPEST must be considered.

(13) Verify that the equipment grounding conductor for each circuit is at least as large as that

given in Table 1-21 based upon the size of the overcurrent device protecting the circuit phase conductors.

(14) Verify that all bonding connections are made through surfaces that have been cleaned of

insulating finishes or by some method, i.e., gouging locknuts fully tightened, that inherently accomplishes the

same result.

(15) Using a clamp-on ammeter, measure the current in each equipment grounding conductor

leaving the panel. Record the current on Part IV of the survey form in Chapter 2.

Wireways, raceways, cable trays.

For all wireways, raceways, cable trays, etc., verify the

following.

(1)

All covers, where applicable, are in place and properly secured.

(2)

All sections are electrically connected, and any insulating finishes in the bonding path have

been removed.

(3) If the wireway, raceway, cable tray, etc., contains neutral or equipment grounding conductors

that have been reidentified, verify that reidentification is accomplished at various intervals throughout their

length.

Equipment. For all equipment, verify the items listed below. In some instances, verification may

require that the equipment be shut down.

1-109