Master Electrician Exam (NEC)Special Occupancies, Equipment, and ConditionsEasy
A master electrician is installing a new sign for a commercial business. The sign is an outline lighting system with individual letters. According to NEC Article 600, what is the minimum required rating for the branch circuit supplying this sign?
- AThe branch circuit rating must be determined by the sign's total connected load.
- B15 amperes
- C30 amperes
- D20 amperes
Show answer & explanationAnswer & explanation
Correct answer: D. 20 amperes
NEC 600.5(B) states that branch circuits supplying signs or outline lighting systems shall be rated at not less than 20 amperes.
Why the other options are wrong
- A. While the total connected load determines the *actual* required ampacity, the NEC sets a *minimum* for these circuits, which is 20A.
- B. 15 amperes is too low for signs and outline lighting systems.
- C. 30 amperes is higher than the minimum required but could be used if the load demands it.
Sign Circuit Minimum (NEC)
The National Electrical Code (NEC) specifies that branch circuits supplying signs and outline lighting systems must have a minimum rating of 20 amperes to ensure adequate capacity and safety for these common outdoor electrical installations.
- Minimum 20A branch circuit rating.
- Applies to signs and outline lighting.
- Found in NEC Article 600.
Memory trick: Signs: Minimum 20 amps, just like your kitchen, because they work hard.