New York Low Voltage Practice flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Class 2 circuit limits

A circuit is Class 2 when its power source is limited to 30 volts and 100 volt-amperes for AC or DC, as defined in NEC Article 725.

Communications cable separation

NEC 800.133 requires at least 2 inches of separation between communications cables and power or Class 1 conductors unless a barrier or listed separation method is used.

Horizontal cable support interval

Exposed horizontal runs of communications cable must be supported at intervals not exceeding 4.5 feet, and within 12 inches of boxes.

UTP bend radius

Four-pair UTP copper cable is generally bent no tighter than four times its diameter during pulling and one time its diameter after installation.

Article 725 scope

NEC Article 725 governs Class 1, Class 2, and Class 3 remote-control, signaling, and power-limited circuits that are not part of a fire alarm or communications system.

Article 760 scope

NEC Article 760 covers fire alarm system wiring and equipment, dividing circuits into power-limited and non-power-limited categories with different wiring method rules.

Plenum cable requirement

NEC 300.22 requires plenum-rated cable such as CMP, CL3P, or FPLP in environmental air spaces unless the cable is installed in a metal raceway.

Working space clearance

NEC 110.26 requires at least 36 inches depth, 30 inches width, and 6.5 feet height of clear working space at electrical equipment requiring servicing while energized.

New York licensing authority

New York State does not issue a statewide electrician license; licensing and permitting are administered by municipalities and counties, so credentials do not transfer automatically.

NYS Uniform Code adoption

The New York State Uniform Fire Prevention and Building Code adopts the NEC by reference, and the edition in force is updated periodically, so verify the adopted edition.

Third-party inspection

Many New York jurisdictions require electrical inspections by approved third-party agencies rather than municipal inspectors, and the AHJ maintains the list of approved agencies.

Concealed work inspection

Concealed low voltage wiring must be inspected before it is covered; a final inspection and certificate of approval follow completion of the work.

Intersystem bonding termination

NEC 250.94 requires a listed intersystem bonding termination at the service equipment, accessible and able to connect at least six communications or low voltage conductors.

Communications shield bonding

NEC 800.100 requires the communications cable shield and metallic members to be bonded to the building grounding electrode system as close as practicable to the point of entry.

CATV shield bonding

NEC 820.100 requires coaxial cable shields for CATV and radio distribution to be bonded to the building grounding electrode system, not to a separate isolated ground rod.

Isolated ground receptacle

An isolated ground receptacle still requires an equipment grounding conductor run back to the panel; isolated ground does not mean the circuit is ungrounded.

Fire alarm cable listings

FPLR is listed for risers, FPLP for plenum air spaces, and FPL for general purpose use; the listing must match the installed environment.

Class A versus Class B

Class A fire alarm circuits provide a redundant path so a single open does not disable the circuit; Class B circuits lack redundancy and an open disables downstream devices.

Supervised circuit trouble

A single open or ground fault on a supervised fire alarm circuit must produce a trouble signal within 200 seconds under NFPA 72.

Pathway survivability

NFPA 72 survivability Level 2 requires 2-hour fire-rated cable or a 2-hour rated enclosure for fire alarm circuits in certain high-rise and occupancy applications.

Cat 6A frequency rating

ANSI/TIA-568 rates Cat 6A cable to 500 MHz, Cat 6 to 250 MHz, Cat 5e to 100 MHz, and Cat 8 to 2000 MHz at a 30-meter length.

Horizontal cabling length

Copper horizontal cabling is limited to 90 meters of permanent link plus 10 meters of patch cords, for a maximum channel length of 100 meters.

Permanent link versus channel

Permanent link testing excludes patch cords and covers the installed cabling; channel testing includes patch cords and measures end-to-end performance.

Single-mode fiber core

Single-mode fiber has a 9-micrometer core and is used for long-distance backbone runs; multimode fiber uses 50 or 62.5 micrometers for shorter in-building runs.

Lockout tagout verification

OSHA 29 CFR 1910.147 requires de-energizing, isolating, locking, tagging, and verifying absence of voltage with a tester rated for the voltage present.

Arc flash boundary

NFPA 70E defines the arc flash boundary as the distance at which incident energy equals 1.2 calories per square centimeter, requiring arc-rated PPE within it.

Test before touch

Verify the voltage tester on a known live source before and after testing, and treat all conductors as energized until absence of voltage is proven.

Trench protective systems

OSHA 29 CFR 1926 Subpart P requires protective systems such as shoring or sloping for excavations 5 feet or deeper, including low voltage cable trenches.

Copper certification tests

Certification testing measures insertion loss, return loss, near-end crosstalk, and far-end crosstalk against TIA-568 category limits and reports pass or fail with margin.

Fiber loss testing

An optical loss test set measures insertion loss and an OTDR locates faults and splices; bidirectional testing is required for accurate loss results.

Commissioning sequence

Verify power and grounding, perform point-to-point checkout, test each subsystem, integrate systems, and document results in a signed commissioning report.

Fire alarm acceptance test

NFPA 72 acceptance testing requires testing every initiating device, notification appliance, and supervisory function, and verifying signal transmission to the supervising station.