The 140U-H2C3-D12 circuit breaker from Allen-Bradley is a Frame H circuit breaker rated for 125 Amps of operating current. The 140U-H2C3-D12 circuit breaker is a three-pole breaker with a thermal-magnetic tripping module. The interrupting rating or breaking capacity of the 140U-H2C3-D12 circuit breaker at 480 Volts AC is 20 to 29 kiloamps. The 140U family of circuit breakers support both electronic and thermal-magnetic trip modules, and the current rating of the breakers with electronics trip modules ranges from 70 to 1200 Amps and the current rating of breakers with thermal-magnetic trip modules ranges from 15 to 800 Amps. Features available on the 140U breakers include rotary variable-depth operating mechanisms, flexible cable operating mechanisms, field/factory installable accessories, and high interrupt ratings in compact dimensions. The140U breakers are globally rated and approved for worldwide applications.

The interrupting rating specifications at 60 Hertz for the 140U-H2C3-D12 circuit breaker are 18 kiloamps at 600 Volts AC, 25 kiloamps at 480 Volts AC, and 25 kiloamps at 240 Volts AC. The service short-circuit breaking ratings at 220 Volts AC, 380 Volts AC, 525 Volts AC and 690 Volts AC are 35 kiloamps, 25 kiloamps, 17 kiloamps, and 3 kiloamps respectively. The 140U-H2C3-D12 circuit breaker dissipates 25 Watts of energy as heat while operating under normal load conditions. The rated insulation voltage for main circuit breaker poles is 750 Volts AC. The operation of the 140U-H2C3-D12 circuit breaker is recommended in environments where the temperature of the air surrounding the breaker remains between 16 and 140 degrees Fahrenheit. The approximate weight and enclosure dimensions for the circuit breaker are 3 pounds and 5.5 x 3 x 3 inches, respectively.