lutfulPremium
join:2005-06-16
Ottawa, ON Reviews:
 ·TekSavvy DSL
| reply to John Galt
said by John Galt:For those who have an interest in such things... I read the beginning 25 pages and general guidelines can be followed for WISP installations. I highlight key points which have already been emphasized during recent Motorola R56 and older discussions. 
- Multiple entry panels may be used; however, the aggregation of all penetrating conductors -
power, signal, data, control lines, and utility conductors -to a single entrance panel or vault should be a goal
- No untreated conductors may penetrate protected areas.
- No lightning protection subsystem conductors may penetrate the zonal boundary of the facility. Bonds for the protection against lightning flashover must be connected to opposite sides of the zonal boundary.
- The ground lugs of terminal protection devices shall be bonded to the distribution frame, junction box, penetration panel, or filter box where mounted. The frame, box, or panel must be grounded directly to the nearest point on the structure or on the EMP/EMI shield
[LK clarification: lightning surge protectors are grounded outside ; indooor (residual) surge protectors are grounded inside. "Resistance of bonds should not exceed one milliohm" is repeated everywhere ]
*** Guidelines for power entry and grounding:
- All power conductors entering or leaving protected regions of the facility must be equipped with EMP power line filters and TIDs.
- No untreated grounding conductors may penetrate or cross the structural boundary.
- External grounding conductors must be bonded to the outside of the structure. Internal grounding conductors must be bonded to the interior surface of the structure or enclosure.
- Ground the neutral ... at the service disconnect
- neutral should not be grounded ... on the load side of the disconnect
- Suppressors installed on service entrance panels shall be grounded to the common neutral grounding conductor connection with minimum length
- Resistance of bonds should not exceed one milliohm
- Ground connections must be 0.6 m outside the facility wall and must extend a minimum of 3 m into soil.
*** "multi-point" ground happens despite silly attempts by electricians to create "single point" grounding:
In many facilities, a single point configuration for the signal reference ground is said to be implemented ... Actually, however, a single point ground configuration does not exist ... typical C4ISR facility is a multi-point grounded system with numerous interconnections between signal references, equipment enclosures, raceways, conduit, and structural members.
*** Guideline for outdoor enclosures:
- The ground terminal of surge arresters and TPDs shall be bonded to the mounting enclosure with minimum length conductors.
- The enclosure shall be mounted directly to the tower structure or will be bonded with a minimum length, flat conductor.
- Filters and TPDs installed for noise suppression and transient protection must be directly grounded to the enclosures of the protected equipment. |
