In Plain English
Quick Answer
A resettable safety switch in your electrical panel that automatically shuts off power when a circuit is overloaded.
Definition
Definition
An automatically operated electrical switch designed to protect a circuit from damage caused by excess current resulting from an overload or short circuit. Unlike fuses, circuit breakers can be reset after tripping. They are rated in amperes and interrupt current when that rating is exceeded.
Context
Why It Matters in Bidding
Breakers are counted line by line from the panel schedule, and their type and rating, standard, GFCI, AFCI, or specialty, can swing the electrical material cost noticeably across a project with many devices. Estimators must match each breaker to the spec and code requirement, because substituting a cheaper standard breaker where code requires GFCI or AFCI protection invites a failed inspection, rework, and lost margin.
Example
Example
Taking off a multifamily project, the electrical estimator prices AFCI breakers for the bedroom circuits and GFCI breakers for the kitchen and bath circuits per code, rather than assuming standard breakers throughout.
See Also
Related Terms
FAQ
Questions Contractors Ask
What is the difference between a circuit breaker and a fuse in an estimate?
A fuse must be replaced after it blows, while a breaker resets. For estimating, modern projects almost always use breakers in panelboards, so the takeoff prices breakers by rating and type from the panel schedule. Fuses still appear in some disconnects and equipment, which estimators capture separately.
How do GFCI and AFCI breakers affect electrical cost?
GFCI and AFCI breakers cost considerably more than standard breakers, and code dictates where each is required, such as kitchens, baths, and bedrooms. Because a panel can hold dozens of breakers, using the correct mix from the start materially affects the bid and prevents costly substitutions at inspection.
Where do you find the breaker quantities for a takeoff?
The panel schedules on the electrical drawings list every breaker by circuit, rating, and pole count, and the specifications call out required types like GFCI or AFCI. Estimators tally directly from these documents, cross-checking against the one-line diagram so no panel or feeder breaker is missed.
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