Flashcards in Ch. 9 - Bonding & Grounding.csv Deck (49):
ITS designer responsibility
Safeguarding personnel, property & equipment
Results of foreign electrical current
Death or Injury
Electrical voltages or currents that are not normally carried by, or expected in, telecommunications dist. systems are referred to as:
Generally, the establishment of a reference for the electrical power source, the electrical equipment, or both is the definition of:
Bonding is the connection between _____
two metallic items
The ITS designer has ______ authority over the ac grounding system.
In new construction the _________ must provide access.
Telecommunications personnel should not __________.
**Max A/C value on bonding conductor _______ amp.
Max DC value on a bonding conductor _______ mA's.
Two point bond test =
earth grounding resistance tester
**In TR's, what's the max value for bonding resistance?
In CO's, what's the max value for bonding resistance?
100 milli-ohms, possibly 50 milli-ohms
Impedance of equipment grounding conductor measured with
ground impedance tester
*The impedance of the equipment grounding conductor should be:
as low as possible
IG-Type (isolated ground) receptacles:
-orange on face
-reduces the effects of EMI and RFI
-not recommended for voice/data
Signal reference grid (SRG), how often do you ground it?
-associated with raised floor in an ER
-ground every fourth pedestal
(Figure 9.1 pic on test)
Commercial bldg grounding & bonding requirements for telecommunications.
ER & EF's grounding begins?
TMGB size =
0.25" x 4"
TGB size =
0.25" x 2"
Locate the TMGB as close to the ________ as possible.
At the EF, the TMGB should be placed in close proximity to the:
Primary/Secondary surge protection
A BCT does what?
grounds the TMGB to the A/C panel w/limit of 30' max
TMGB - Primary?
TMGB - Alternative?
1. BCT to A/C panel
2. Nearest structural steel
ER or TR
0.25" x 2"
The bonding infrastructure for the TR will depend on the referencing of its:
-between TR's on multiple floors w/ ultimate connection to the EF's TMGB.
1.Max distance #6 AWG =
2.Over 100' =
2. IAEI / up a size in AWG
Typical bonding connections:
Compression type connectors & clamps
The visual inspection of bonding connections can usually reveal problems such as:
Since lightning exposure cannot always be accurately examined, the ITS designer must consider _______ when evaluating a site for exposure.
*Inter-building circuits (OSP) are to be considered exposed to lightning unless:
1. metro area (buildings)
2. runs of 140' or less
3. (5) or less storms per year
NFPA 780 cover lightning exposure & defines exposed as anything:
Above ground and outside an area under and/or nearly under a lightning protection system.
Buries cable can detect ground strikes up to _______.
Bonding & Grounding
Commercial building cabling standard
Recommended practices power & grounding
Lightning Protection Institute (LPI)
Publishes material & certifies contractors
NEC chapter B
NEC Article 250
Standard for installation of Lightning Protection systems
If a raised floor is used within an ER, TR or data processing center; a bonding conductor must be run between the associated grounding busbar and to at least _____ point(s) within the signal reference grid (SRG).
The impedance of an electrically conductive path is influenced by:
Inductive & Capacitance???
Generally, the connection intended to safely and effectively equalize the potential difference between two metallic items is the definition of:
The primary purpose of the equipment grounding system is to:
Enhance personnel safety and reduce the likelihood of a fire hazard
The grounding (earthing) system that should be in place at every site is the:
Equipment grounding system
Telecommunications bonding infrastructure
ac grounding electrode system