CT Electrician flashcards
CT Electrician · Build recall with a focused review session.
32 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); it lets you solve for any one of the three values when the other two are known in a DC or resistive AC circuit.
- Three-phase power formula
- For a balanced three-phase load, true power in watts equals 1.732 times line voltage times line current times the power factor of the load.
- Voltage-drop formula
- Single-phase voltage drop equals two times K times current times length in feet, divided by conductor circular mils, where K is 12.9 for copper and 21.2 for aluminum.
- GFCI requirements
- Ground-fault circuit-interrupter protection is required for 125-volt, 15- and 20-ampere receptacles in bathrooms, kitchens, garages, outdoors, crawl spaces, and unfinished basements of dwellings.
- AFCI requirement
- Arc-fault circuit-interrupter protection is required on branch circuits supplying outlets in dwelling unit kitchens, bedrooms, living rooms, laundry areas, and similar rooms.
- Working clearance rule
- Switchboards and panelboards need a clear working space at least 3 feet deep, 30 inches wide, and 6½ feet high, increased where live parts are exposed.
- Conduit fill percentages
- A raceway may be filled to 53 percent for one conductor, 31 percent for two conductors, and 40 percent for three or more, based on Chapter 9 tables.
- Box fill counting
- Each 14 AWG conductor counts 2.0 cubic inches, 12 AWG 2.25, and 10 AWG 2.5; each device yoke counts as two conductors of the largest size.
- NM cable support
- Nonmetallic-sheathed cable must be secured within 12 inches of each box and supported at intervals not exceeding 4½ feet along its run.
- Motor branch-circuit sizing
- Branch-circuit conductors supplying a single motor are sized at 125 percent of the motor full-load current taken from the code tables, not the nameplate current.
- Motor disconnecting means
- A disconnecting means must be within sight of the motor and its controller, or capable of being locked in the open position, so maintenance is safe.
- Flexible cord restriction
- Flexible cords and cables may not be used as a substitute for the fixed wiring of a structure, nor run through walls, ceilings, or floors.
- Class I Division 1
- A location where flammable gases or vapors are present under normal operating conditions, or frequently during repair and maintenance, is Class I, Division 1.
- Health care redundant ground
- Patient care areas require an insulated copper equipment grounding conductor terminating at the receptacle grounding terminal, in addition to the metallic raceway or cable armor ground.
- Pool equipotential bonding
- Pool shells, metal fittings, ladders, and adjacent metal must be connected to a common bonding grid with a solid copper conductor not smaller than 8 AWG.
- PV rapid shutdown
- Photovoltaic systems must provide a rapid shutdown function that reduces conductor voltage within the array boundary to a safe level for firefighters.
- Emergency versus standby
- Emergency systems protect life safety and egress lighting under Article 700; legally required standby is Article 701; optional standby for convenience loads is Article 702.
- Class 2 circuit limit
- A Class 2 circuit supplied by a listed Class 2 power source is limited to 100 volt-amperes, which permits smaller conductors and less stringent installation rules.
- Primary protector
- A listed primary protector is required on communications conductors entering a building where they are exposed to lightning or to contact with power conductors.
- Communications bonding
- Communications cable must be bonded to the building grounding electrode system with an insulated copper conductor not smaller than 14 AWG.
- Lump-sum contract
- A contract stating one fixed price for the complete scope of work, placing the risk of quantity errors and rising material costs on the contractor.
- Retainage
- A percentage of each progress payment, commonly 5 to 10 percent, withheld by the owner until final completion is accepted.
- Change order
- A written, signed modification to the contract scope, price, or schedule; work performed without one may not be paid.
- Scale reading
- On a drawing marked 1/8 inch equals 1 foot, one inch measured on the plan represents 8 feet of actual building dimension.
- Bid components
- A bid price equals direct materials plus direct labor plus subcontractors plus overhead plus profit, with contingency added where the scope is uncertain.
- Riser diagram
- A single-line drawing showing the service entrance, feeders, panelboards, disconnects, and grounding, without physical dimensions or exact routing.
- Lockout/tagout
- The procedure of opening the disconnect, applying a personal lock and tag, and verifying the circuit is de-energized before work begins.
- Limited approach boundary
- For exposed live parts at 750 volts or less, the limited approach boundary is 10 feet, and only qualified persons may cross it.
- Ladder 4-to-1 rule
- The base of a ladder is set out 1 foot for every 4 feet of working height, and the ladder extends 3 feet above the landing.
- Connecticut licensing agency
- Electrical contractor and journeyman licenses in Connecticut are issued and renewed by the Department of Consumer Protection under Chapter 393 of the General Statutes.
- E-1 and E-2 licenses
- The E-1 license permits a contractor to perform and contract for unlimited electrical work; the E-2 journeyman license permits work under an E-1 contractor.
- Permit and inspection
- A local building official issues the electrical permit and the electrical inspector approves the work, which must be inspected before it is concealed.