B-Curve Circuit Breakers

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38 Products

DIN-Rail Mount Equipment Circuit Breakers

Also known as supplemental protectors, these circuit breakers mount directly to DIN rail downstream from a branch circuit breaker to protect a single piece of equipment. They are rated UL1077 for protection against overloads and short circuits. Because they are thermal-magnetic, these breakers trip two ways. They either trip when heat is generated slowly by consistent low-level overload current, or they trip quickly when the magnetic coil senses a high-current short circuit.

Breakthrough current is the maximum current that the circuit breaker can safely stop in the event of a short circuit.

B-trip circuit breakers are best for protecting sensitive equipment, such as programmable logic controllers (PLCs) and sensors, which could be damaged by a spike in current. These circuit breakers will trip if a rush of current reaches 3 to 5 times their rated current.

Shunt trips receive a signal from equipment to trip your circuit breaker in situations other than overload or short circuit conditions. For example, use them with a smoke detector to shut off power to a system in the event of a fire.

Auxiliary contacts send a signal to other equipment when the circuit trips. They can activate a warning light, initiate a shutdown, or start a backup power source.

Distribution bars simplify wiring by powering multiple adjacent circuit breakers without needing separate wires for each one. This cuts down on assembly time and space. Cut them to the number of terminals that you need.

Extension terminals raise the wire connection point above distribution bars for easy access to connect power to a set of circuit breakers.

Distribution bar end covers seal the live ends of distribution bars to prevent injury and damage.

Distribution bar terminal covers shield unused, live terminals on distribution bars to prevent injury and damage.

For technical drawings and 3-D models, click on a part number.

Circuit Breakers

1 Pole

2 Pole

3 Pole

B Trip Type
Current, A	Voltage	Frequency, Hz	Breakthrough Current	For DIN Rail Size, mm	Wire Connection Type	Ht.	Wd.	Dp.	Temp. Range, °F	Specifications Met		Each
1 Pole—Toggle Style
1	277V AC/48V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 48 V DC	35	Screw-Clamp Terminals	3.15"	0.7"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
5	277V AC/48V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 48 V DC	35	Screw-Clamp Terminals	3.15"	0.7"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	00000
10	277V AC/48V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 48 V DC	35	Screw-Clamp Terminals	3.15"	0.7"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	00000
15	277V AC/48V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 48 V DC	35	Screw-Clamp Terminals	3.15"	0.7"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	00000
20	277V AC/48V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 48 V DC	35	Screw-Clamp Terminals	3.15"	0.7"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	00000
30	277V AC/48V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 48 V DC	35	Screw-Clamp Terminals	3.15"	0.7"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	00000
2 Pole—Toggle Style
1	277V AC/480YV AC/96V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC 10,000 A @ 96 V DC	35	Screw-Clamp Terminals	3.15"	1.4"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
5	277V AC/480YV AC/96V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC 10,000 A @ 96 V DC	35	Screw-Clamp Terminals	3.15"	1.4"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
10	277V AC/480YV AC/96V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC 10,000 A @ 96 V DC	35	Screw-Clamp Terminals	3.15"	1.4"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
15	277V AC/480YV AC/96V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC 10,000 A @ 96 V DC	35	Screw-Clamp Terminals	3.15"	1.4"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
20	277V AC/480YV AC/96V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC 10,000 A @ 96 V DC	35	Screw-Clamp Terminals	3.15"	1.4"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
30	277V AC/480YV AC/96V DC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC 10,000 A @ 96 V DC	35	Screw-Clamp Terminals	3.15"	1.4"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
3 Pole—Toggle Style
1	277V AC/480YV AC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC	35	Screw-Clamp Terminals	3.15"	2.09"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
5	277V AC/480YV AC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC	35	Screw-Clamp Terminals	3.15"	2.09"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
10	277V AC/480YV AC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC	35	Screw-Clamp Terminals	3.15"	2.09"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
15	277V AC/480YV AC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC	35	Screw-Clamp Terminals	3.15"	2.09"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
20	277V AC/480YV AC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC	35	Screw-Clamp Terminals	3.15"	2.09"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
30	277V AC/480YV AC	50/60	10,000 A @ 277 V AC 10,000 A @ 480 V AC	35	Screw-Clamp Terminals	3.15"	2.09"	2.36"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000

Shunt Trips

Shunt Trip

Voltage	Current, A	Frequency, Hz	For DIN Rail Size, mm	Wire Connection Type	Ht.	Wd.	Dp.	Temp. Range, °F	Specifications Met		Each
12-110V AC/12-60V DC	63	50/60	35	Screw-Clamp Terminals	4.13"	0.7"	2.36"	25° to 100°	UL 489, UL Listed, CSA Certified, CE Marked, IEC 60898	00000000	000000
110-415V AC/110-230V DC	40	50/60	35	Screw-Clamp Terminals	4.13"	0.7"	2.36"	25° to 100°	UL 489, UL Listed, CSA Certified, CE Marked, IEC 60898	00000000	00000

Auxiliary Contacts

Auxiliary Contact

Voltage	Current, A	Frequency, Hz	Industry Designation	No. of Circuits Controlled	Switch Starting Position	For DIN Rail Size, mm	Wire Connection Type	Ht.	Wd.	Dp.	Temp. Range, °F	Specifications Met		Each
230V AC	6	50/60	DPST	2	1 Off (Normally Open) and 1 On (Normally Closed)	35	Screw-Clamp Terminals	3.15"	0.35"	2.36"	-40° to 165° F	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000

Distribution Bars

Distribution Bar

				Terminal
For No. of Poles	No. of Terminals	Voltage	Current, A	Ctr.-to-Ctr.	Wd.	Ht.	Wd.	Dp.	Temp. Range, °F	Specifications Met		Each
1	57	277V AC/480YV AC	80	0.7"	0.22"	0.59"	39.72"	0.59"	25° to 212°	UL 1077, UL Listed, CE Marked, IEC 60947-2	00000000	000000
2	56	277V AC/480YV AC	80	0.7"	0.24"	1.46"	39.02"	0.87"	25° to 212°	UL 1077, UL Listed, CE Marked, IEC 60947-2	00000000	000000
3	57	277V AC/480YV AC	80	0.7"	0.24"	1.46"	39.72"	0.87"	25° to 212°	UL 1077, UL Listed, CE Marked, IEC 60947-2	00000000	000000

Extension Terminals

Extension Terminal

For No. of Poles	Voltage	Current, A	Frequency, Hz	Wire Connection Type	Ht.	Wd.	Dp.	Temp. Range, °F	Specifications Met		Each
1	277V AC/480YV AC	115	50/60	Screw-Clamp Terminals	1.14"	1.42"	0.67"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	000000
2, 3	277V AC/480YV AC	4	50/60	Screw-Clamp Terminals	1.14"	2.36"	0.67"	-40° to 165°	UL 1077, UL Listed, CSA Certified, CE Marked, IEC 60947-2	00000000	00000

Distribution Bar End Covers

Distribution Bar End Cover

For No. of Poles	Ht.	Wd.	Dp.	Material	Temp. Range, °F	Specifications Met	Pkg. Qty.		Pkg.
1	0.55"	0.19"	0.37"	Plastic	-40° to 165°	UL 1077, CSA Certified, CE Marked, IEC 60947-2	10	00000000	000000
2, 3	0.94"	0.85"	0.38"	Plastic	-40° to 165°	UL 1077, CSA Certified, CE Marked, IEC 60947-2	10	00000000	00000

Distribution Bar Terminal Covers

Distribution Bar Terminal Cover

For No. of Terminals	Ht.	Wd.	Dp.	Material	Temp. Range, °F	Specifications Met		Each
5	0.94"	3.35"	0.47"	Plastic	-40° to 165°	UL 1077, CSA Certified, CE Marked, IEC 60947-2	00000000	00000

DIN-Rail Mount Branch Circuit Breakers

Mount these circuit breakers directly to DIN rail to protect equipment and wiring in an area of your facility from overloads and short circuits. They meet UL 489 requirements for branch circuit protection and are certified as current limiting, so they protect equipment by minimizing passing current during a short circuit. Because they are thermal-magnetic, these breakers trip two ways. They either trip when heat is generated slowly by consistent low-level overload current, or they trip quickly when the magnetic coil senses a high-current short circuit.