Brochure

PowerPact H-, J-, and L-Frame Circuit Breakers

Trip Curves

232

J-Frame Electronic Trip Circuit Breakers—250 A Frame

Figure 109: Micrologic 3.2 and 3.2-W Electronic Trip Unit Long-Time Trip Curve

MICROLOGIC™ ELECTRONIC TRIP UNITS

Micrologic™ 3.2 and 3.2-W

Long Time Trip Curve

250A J-Frame

The time-current curve information is to be used

for application and coordination purposes only.

Notes:

1. There is a thermal-imaging effect that can act

to shorten the long-time delay. The thermal

imaging effect comes into play if a current

above the long-time delay pickup value exists

for a time and then is cleared by the tripping of

a downstream device or the circuit breaker

itself. A subsequent overload will cause the

circuit breaker to trip in a shorter time than

normal. The amount of time delay reduction is

inverse to the amount of time that has elapsed

since the previous overload. Approximately 20

minutes is required between overloads to

completely reset thermal-imaging.

2. Total clearing times shown include the

response times of the trip unit, the circuit

breaker opening, and the extinction of the

current.

Curves apply from -35ºC to +70ºC (-31ºF to

+158ºF) ambient temperature.