WebCircuit breakers, however, are slash-rated or straight-rated. An example is a 208Y/120 volt (V) slash-voltage rating. This means the device is intended to open more than one pole in a fault at line voltage (208V), and the “voltage to ground” rating (120V) is the maximum voltage for opening a single pole in a fault. WebSlash ratings (e.g. 480/277V) are only intended for solidly grounded wye systems. Series Ratings . It is possible to enhance the ampere interrupting rating of circuit breakers with a higher rated upstream circuit breaker or with an upstream current-limiting fuse. Although this can allow the use of less expensive downstream circuit
Low-Voltage Circuit Breaker Requirements EC&M
WebMar 28, 2024 · “A circuit breaker with a slash rating, such as 120/240v or 480/277v, shall be permitted to be applied in a solidly grounded circuit where the voltage of any conductor to ground does not exceed the lower of the two values of the ciruit breaker’s voltage rating and the nominal voltage between any two conductors does not exceed the higher value of … WebFeb 6, 2024 · When applied in group motor applications, they can achieve a straight rating provided the upstream overcurrent protective device is straight rated. Additionally, some circuit breakers may have slash-voltages ratings, particularly miniature IEC-style circuit breakers. Fuses are all straight-rated. cue methode
Understanding Circuit Breaker Ratings and Its Specification
Webovercurrent protective device must be utilized. For example, a 480V circuit breaker may have to open an overcurrent at 480V with only one pole, such as might occur when Phase A goes to ground on a 480V, B-phase, corner grounded delta system. The NEC® addresses slash voltage ratings for circuit breakers in 240.86 restricting their use to ... WebOct 21, 2016 · A circuit breaker with a slash rating, such as 120/240V or 480Y/277V can be installed in a solidly grounded circuit where the nominal voltage of any conductor to ground does not exceed the lower of the two values of the circuit breaker’s voltage rating and the nominal voltage between any two conductors does not exceed the higher value of the ... WebApplying a slash-rated breaker in such a system may result in complete device failure when a full voltage fault exceeds the circuit breaker rating. This is a violation of Section 240.85, … eastern aging bangor maine