standards and guidelines for communication sites - Radio And ...
standards and guidelines for communication sites - Radio And ... standards and guidelines for communication sites - Radio And ...
ESD CONTROL PROGRAM APPENDIX C: PROTECTING AGAINST ELECTROSTATIC DISCHARGE IN EQUIPMENT ROOMS AND DISPATCH CENTERS NOTE: Non-dissipative floor mats or chair mats should never be placed over dissipative flooring material. If floor mats are used, they shall be of a dissipative material with a grounding conductor that is effectively bonded to the common grounding point or the multi-point grounding system. C.3.5 DISPATCH POSITION DESKTOPS Work surfaces on the operator position desktops that may be touched by the operator should have a resistance to ground measurement of between 10 6 and 10 9 ohms when measured using the test method of ANSI/ESD -S4.1-1997 or later. If an existing desktop does not meet this requirement, an ESD protective mat can be installed under and around the keyboard and mouse. To be effective, the ESD protective desktop or ESD protective mat must be bonded to the operator position common grounding point. (See ANSI T1.321-R2000, section 4.4 and ANSI/ESD S4.1-1997 for additional information.) To help avoid ESD, the operator must touch the ESD protective desktop or ESD protective mat before connecting to the headset jack or touching equipment or grounded objects. C.3.6 VIDEO DISPLAY TERMINALS If a cathode-ray tube (CRT) monitor is used, installation of a electrostatic shield such as a properly grounded bezel or a conductive anti-glare shield that is properly bonded back to the common grounding point will be of some benefit (ANSI T1.321-R2000). Another option is installing LCD displays, which do not generate high electrostatic fields. C.3.7 EQUIPMENT BONDING, GROUNDING, AND SURGE PROTECTION All equipment, including headset jacks, located in an ESD-susceptible area, shall be properly bonded and grounded in accordance with the requirements of “Grounding (Earthing) for Dispatch Centers and Network Operator Positions,” on page 5-62. Surge suppression should be provided in accordance with “Surge Protection Considerations for Dispatch Centers and Operator Positions,” on page 7-43. C.4 ESD CONTROL PROGRAM After preventive measures have been implemented to help eliminate or dissipate electrostatic charges, an effective ESD control program should be implemented to maintain the environment. For additional information on how to establish an effective ESD control program, see Part Two - Principles of ESD Control at the Electrostatic Discharge Association web site (http://www.esda.org/aboutesd.html). C-4 68P81089E50-B 9/1/05
APPENDIX D GROUNDING (EARTHING) ELECTRODE SYSTEM TESTING/VERIFICATION D Procedures in this Appendix shall not be performed by untrained or unqualified personnel, nor are any procedures herein intended to replace proper training. It is required that personnel attempting to measure the resistance of a grounding (earthing) electrode system receive prior formal training on the subject and on its associated safety hazards. All applicable laws, rules and codes regulating the work on electrical systems shall be complied with at all times. This appendix provides procedures for performing resistance testing of the site grounding electrode system. The resistance of a grounding electrode system shall be measured after its installation and before it is bonded to the power company neutral wire or any other utility, such as the telephone ground or metallic pipes. Periodic testing should be performed on the site annually when the site grounding electrode system can be safely disconnected from the power company neutral wire (if using the fall-ofpotential test). Suggested best practice is to perform the test at three-month intervals for the first year and every 21 months thereafter (MIL-HDBK-419A). NOTE: Grounding electrode system testing should be performed anytime the site is suspected to have taken a direct lightning strike. NOTE: Throughout this appendix the terms grounding and earthing are used synonymously. WARNING It should be strongly impressed on all test personnel that a lethal potential can exist between the station ground and a remote ground if a power-system fault involving the station ground occurs while ground tests are being made. Because one of the objectives of tests on a station-ground system is to establish the location of remote earth for both current and potential electrodes, the leads to these electrodes must be treated as though a possible potential could exist between test leads and any point on the station ground grid. Under no circumstances should the two hands or other parts of the body be allowed to complete the circuit between points of possible high-potential difference. (See IEEE STD 81-1983, section 5.1.) WARNING To help protect against shock hazard, wearing insulated electrician's gloves is recommended while performing grounding electrode system testing. 68P81089E50-B 9/1/05 D-1
- Page 419 and 420: STANDARDS AND GUIDELINES FOR COMMUN
- Page 421 and 422: STANDARDS AND GUIDELINES FOR COMMUN
- Page 423 and 424: STANDARDS AND GUIDELINES FOR COMMUN
- Page 425 and 426: STANDARDS AND GUIDELINES FOR COMMUN
- Page 427 and 428: STANDARDS AND GUIDELINES FOR COMMUN
- Page 429 and 430: STANDARDS AND GUIDELINES FOR COMMUN
- Page 431 and 432: STANDARDS AND GUIDELINES FOR COMMUN
- Page 433 and 434: APPENDIX B SOIL RESISTIVITY MEASURE
- Page 435 and 436: STANDARDS AND GUIDELINES FOR COMMUN
- Page 437 and 438: STANDARDS AND GUIDELINES FOR COMMUN
- Page 439 and 440: STANDARDS AND GUIDELINES FOR COMMUN
- Page 441 and 442: STANDARDS AND GUIDELINES FOR COMMUN
- Page 443 and 444: STANDARDS AND GUIDELINES FOR COMMUN
- Page 445 and 446: STANDARDS AND GUIDELINES FOR COMMUN
- Page 447 and 448: STANDARDS AND GUIDELINES FOR COMMUN
- Page 449 and 450: STANDARDS AND GUIDELINES FOR COMMUN
- Page 451 and 452: STANDARDS AND GUIDELINES FOR COMMUN
- Page 453 and 454: STANDARDS AND GUIDELINES FOR COMMUN
- Page 455 and 456: STANDARDS AND GUIDELINES FOR COMMUN
- Page 457 and 458: STANDARDS AND GUIDELINES FOR COMMUN
- Page 459 and 460: STANDARDS AND GUIDELINES FOR COMMUN
- Page 461 and 462: STANDARDS AND GUIDELINES FOR COMMUN
- Page 463 and 464: STANDARDS AND GUIDELINES FOR COMMUN
- Page 465 and 466: STANDARDS AND GUIDELINES FOR COMMUN
- Page 467 and 468: APPENDIX C PROTECTING AGAINST ELECT
- Page 469: STANDARDS AND GUIDELINES FOR COMMUN
- Page 473 and 474: STANDARDS AND GUIDELINES FOR COMMUN
- Page 475 and 476: STANDARDS AND GUIDELINES FOR COMMUN
- Page 477 and 478: STANDARDS AND GUIDELINES FOR COMMUN
- Page 479 and 480: STANDARDS AND GUIDELINES FOR COMMUN
- Page 481 and 482: STANDARDS AND GUIDELINES FOR COMMUN
- Page 483 and 484: STANDARDS AND GUIDELINES FOR COMMUN
- Page 485 and 486: STANDARDS AND GUIDELINES FOR COMMUN
- Page 487 and 488: STANDARDS AND GUIDELINES FOR COMMUN
- Page 489 and 490: STANDARDS AND GUIDELINES FOR COMMUN
- Page 491 and 492: STANDARDS AND GUIDELINES FOR COMMUN
- Page 493 and 494: STANDARDS AND GUIDELINES FOR COMMUN
- Page 495 and 496: STANDARDS AND GUIDELINES FOR COMMUN
- Page 497 and 498: APPENDIX E GENERAL CONVERSIONS AND
- Page 499 and 500: STANDARDS AND GUIDELINES FOR COMMUN
- Page 501 and 502: STANDARDS AND GUIDELINES FOR COMMUN
- Page 503 and 504: APPENDIX F R56 COMPLIANCE CHECKLIST
- Page 505 and 506: STANDARDS AND GUIDELINES FOR COMMUN
- Page 507 and 508: STANDARDS AND GUIDELINES FOR COMMUN
- Page 509 and 510: I NDEX Index Index AC power cabling
- Page 511 and 512: STANDARDS AND GUIDELINES FOR COMMUN
- Page 513 and 514: STANDARDS AND GUIDELINES FOR COMMUN
- Page 515 and 516: STANDARDS AND GUIDELINES FOR COMMUN
- Page 517 and 518: STANDARDS AND GUIDELINES FOR COMMUN
APPENDIX<br />
D<br />
GROUNDING (EARTHING) ELECTRODE SYSTEM<br />
TESTING/VERIFICATION D<br />
Procedures in this Appendix shall not be per<strong>for</strong>med by untrained or unqualified personnel, nor<br />
are any procedures herein intended to replace proper training. It is required that personnel<br />
attempting to measure the resistance of a grounding (earthing) electrode system receive prior<br />
<strong>for</strong>mal training on the subject <strong>and</strong> on its associated safety hazards. All applicable laws, rules <strong>and</strong><br />
codes regulating the work on electrical systems shall be complied with at all times.<br />
This appendix provides procedures <strong>for</strong> per<strong>for</strong>ming resistance testing of the site grounding<br />
electrode system. The resistance of a grounding electrode system shall be measured after its<br />
installation <strong>and</strong> be<strong>for</strong>e it is bonded to the power company neutral wire or any other utility, such<br />
as the telephone ground or metallic pipes.<br />
Periodic testing should be per<strong>for</strong>med on the site annually when the site grounding electrode<br />
system can be safely disconnected from the power company neutral wire (if using the fall-ofpotential<br />
test). Suggested best practice is to per<strong>for</strong>m the test at three-month intervals <strong>for</strong> the first<br />
year <strong>and</strong> every 21 months thereafter (MIL-HDBK-419A).<br />
NOTE: Grounding electrode system testing should be per<strong>for</strong>med anytime the site is suspected to have taken a<br />
direct lightning strike.<br />
NOTE: Throughout this appendix the terms grounding <strong>and</strong> earthing are used synonymously.<br />
WARNING<br />
It should be strongly impressed on all test personnel that a lethal potential can<br />
exist between the station ground <strong>and</strong> a remote ground if a power-system fault<br />
involving the station ground occurs while ground tests are being made. Because<br />
one of the objectives of tests on a station-ground system is to establish the<br />
location of remote earth <strong>for</strong> both current <strong>and</strong> potential electrodes, the leads to<br />
these electrodes must be treated as though a possible potential could exist<br />
between test leads <strong>and</strong> any point on the station ground grid. Under no<br />
circumstances should the two h<strong>and</strong>s or other parts of the body be allowed to<br />
complete the circuit between points of possible high-potential difference. (See<br />
IEEE STD 81-1983, section 5.1.)<br />
WARNING<br />
To help protect against shock hazard, wearing insulated electrician's gloves is<br />
recommended while per<strong>for</strong>ming grounding electrode system testing.<br />
68P81089E50-B 9/1/05 D-1
Change language