Service and distribution
Electrical service: the supply and associated equipment bringing power to the premises. Service rating: a defined rating of service equipment, not a promise that every new load fits. Panelboard or panel: equipment that distributes power through overcurrent protective devices. Main disconnect: the service or building disconnecting means. Subpanel: an additional distribution panel supplied from upstream equipment; it adds spaces but not utility capacity. Feeder: conductors supplying downstream distribution equipment or loads.
- Meter equipment: utility metering enclosure and related components
- Bus: conductive assembly inside distribution equipment
- Breaker space: physical position for a compatible protective device
- Circuit directory: labeling that identifies what each circuit serves
Circuits and protection
Branch circuit: wiring from the final overcurrent device to outlets or equipment. Dedicated circuit: a circuit assigned to specified equipment or loads. Circuit breaker: a protective device that opens under defined overcurrent conditions; it is not an on-off troubleshooting tool. Fuse: an overcurrent device that opens by melting its element. GFCI: protection intended to reduce shock risk from ground-fault current. AFCI: protection intended to address certain arcing conditions. Surge protective device: equipment intended to limit specified transient overvoltage; it is not protection from every power problem.
- Disconnect: a means to isolate equipment or circuits
- Overcurrent: current exceeding the equipment or conductor’s intended limit
- Ground fault: unintended current path to ground or grounded parts
- Short circuit: unintended low-impedance connection between points of different potential
Capacity, grounding, and project documents
Load calculation: an approved method for evaluating expected electrical demand; it is not a simple total of breaker handles. Load management: listed and approved controls that manage when or how certain loads operate. Grounding: connection of systems or equipment to earth under defined requirements. Bonding: connecting conductive parts to establish electrical continuity and an effective fault-current path. Work notice or permit: authorization or notification required by the responsible authority. Rough inspection: review before specified work is concealed. Final inspection: review at project completion; it does not replace a contract warranty or whole-building certification.
- Change order: written change to scope, price, or time
- Allowance: budget placeholder with defined assumptions
- Commissioning: startup, configuration, and verification of equipment or systems
- Closeout: final approvals, records, labels, manuals, warranties, and unresolved-item documentation
How to use a technical term in an estimate
Ask the provider to point to the exact equipment or scope, explain why it applies, identify what is included and excluded, and describe the permit, inspection, testing, and documentation. If two estimates use the same term but price different work, request a line-by-line clarification.