New Jersey Low Voltage Practice flashcards

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

Ohm's law

Current equals voltage divided by resistance (I = E/R). For AC circuits with reactance, impedance Z replaces resistance, and the current and voltage may be out of phase.

Voltage drop formula

Single-phase VD = 2 × K × I × L ÷ CM, with K about 12.9 for copper. Three-phase uses 1.732 instead of 2. Keep total drop within limits.

Box fill calculation

Count each conductor by its volume allowance (14 AWG = 2.0 in³, 12 AWG = 2.25 in³), add device and grounding allowances, and compare with the box's marked volume.

Ampacity correction factors

Table ampacities are adjusted for elevated ambient temperature and for more than three current-carrying conductors in a raceway. Both factors apply when both conditions exist.

Class 2 circuit limits

A Class 2 circuit is limited to 30 volts and 100 volt-amperes under the power-supply listing. Its cable and wiring methods must match the location, such as plenum or riser.

Equipment grounding conductor

A conductor that provides a low-impedance fault-current path back to the source, allowing the overcurrent device to open. It carries current only during a fault.

Motor branch circuit sizing

Branch-circuit conductors are at least 125 percent of motor nameplate current. Overload protection is sized from nameplate current; short-circuit protection from the locked-rotor table.

Three-phase power

Real power for a balanced three-phase load equals 1.732 × E × I × power factor. Apparent power in volt-amperes omits the power factor.

NEC Article 725 scope

Article 725 governs Class 1, 2, and 3 remote-control, signaling, and power-limited circuits. It sets voltage, power, and wiring-method limits for these circuits.

Plenum cable marking

CL2P and CL3P cables are listed for installation in air-handling plenums. CL2R and CL3R are riser-rated. Using the wrong listing in a plenum violates the code.

Working clearance depth

NEC 110.26 requires 3 ft depth at 0–150 volts to ground, 3.5 ft at 151–300 volts, and 4 ft at 301–600 volts in front of electrical equipment.

GFCI protection locations

Dwelling bathrooms, kitchens, garages, outdoors, unfinished basements, and receptacles within 6 ft of a sink require ground-fault circuit-interrupter protection under the NEC.

Intersystem bonding termination

A listed means to connect communications, antenna, and other low-voltage system grounding conductors to the building grounding electrode system, using at least 14 AWG copper.

Listed versus approved

Listed means equipment appears in a list published by a nationally recognized testing laboratory. Approved means acceptable to the authority having jurisdiction, which may require listing.

Conduit fill tables

NEC Chapter 9 Table 1 gives allowable percent fill by conductor count; Table 4 gives conduit dimensions; Table 5 gives insulated conductor dimensions used in fill calculations.

AFCI requirement

Arc-fault circuit-interrupter protection is required for most 120-volt branch circuits in dwellings, including bedrooms, to detect arcing that can start a fire.

Electrical Contractors Licensing Act

N.J.S.A. 45:5A-1 et seq., enacted in 1962, created the Board of Examiners of Electrical Contractors and requires licensing to perform electrical contracting work for compensation.

Responsible licensee

A licensed electrical contractor business must designate a master electrician as the responsible licensee. If that person leaves, the business must promptly designate a replacement.

License classes

New Jersey licenses electrical contractors, master electricians, journeyman electricians, and qualified journeymen. Each class has separate qualifications, examination requirements, and scope of work.

Board disciplinary grounds

The Board may discipline licensees for fraud, gross negligence, code violations, failure to obtain permits, and aiding unlicensed practice, with penalties up to revocation and fines.

Unlicensed practice penalty

Performing electrical contracting without a license, or helping an unlicensed person do so, violates the Act and exposes the violator to civil penalties enforced by the Board.

Continuing education renewal

License renewal requires continuing education hours set by Board regulation. Licensees must track and submit completed hours and keep records supporting the renewal.

License number display

Board rules require the license number to appear on advertisements, contracts, and business vehicles. Changes of address or responsible licensee must be reported to the Board.

Electrical permit requirement

Electrical work requires a permit from the local enforcing agency before starting. The electrical subcode official issues permits and inspects the completed work.

Rough and final inspections

The Uniform Construction Code requires a rough inspection before wiring is concealed and a final inspection after completion. Concealed work must be approved before covering.

Certificate of occupancy

The construction official issues a certificate of occupancy only after all subcode approvals, including electrical, are obtained. Without it, the space may not be legally occupied.

Home improvement registration

Residential electrical contracting may also require registration with the Division of Consumer Affairs as a home improvement contractor, separate from the electrical contractor license.

Lockout/tagout

OSHA and NJ PEOSH require de-energizing and locking out circuits before work. Energized work requires justification, PPE, and documented safe work practices.

Assured grounding program

A written assured equipment grounding conductor program permits cord sets and tools to be tested at set intervals instead of using GFCI protection on construction sites.

Insurance verification

Before signing a contract, verify the general liability and workers' compensation certificates of insurance and review indemnification and additional-insured clauses carefully.

Job record retention

Retain permits, inspection approvals, test results, and as-built drawings. These records support warranty claims, change-order disputes, and defense of code-compliance allegations.