The Klixon 2TC49 dual safety circuit breaker represents a refinement in electrical control and circuit protection. The 2TC dual safety circuit breaker incorporates a fusible element in a standard 2TC (MS 3320) package size to provide redundant protection in hard fault conditions.

"Hard Fault" Tripping
The 2TC dual safety circuit breaker operates identically to a standard circuit breaker under all normal conditions, including short circuit. In the event of circumstances which disable the internal circuit breaker mechanisms such that the device is able to carry current but unable to clear an overload via its normal means, the dual safety element acts as a built in fuse to provide redundant circuit protection.

The key part in the dual safety design is a two part current carrying element joined by a special alloy. The geometry and material of the element determine its heating properties. The element’s heating properties are slower than the bimetal sensor but faster than the smoke curve of the wire the rating is designed to protect. In the case where the standard mechanism is disabled or cannot operate normally, the separable element "fuses" open, interrupting current.

The benefits of the dual safety design result in calibrated over–current protection (based on the fuse times) and specified post fuse dielectric properties for system and human protection.

10G minimum, 50–500 Hz

50G

10G

25 gram maximum

2½–10 amps: 6,000 amps at 28 VDC
2½ amps: 2,800 amps at 120 VAC, 400 Hz
3–10 amps: 2,500 amps at 120 VAC, 400 Hz

2,500 cycles: 120 VAC, 400 Hz inductive
5,000 cycles: 120 VAC, 400 Hz resistive
2,500 cycles: 30 VDC inductive
5,000 cycles: 30 VDC resistive
10,000 cycles: Mechanical, no load

1125 VAC Min (1MA)

900 VAC (1MA)

Trip Time in seconds

25

115%

138%

5–20

0.5–2.00

0.12–0.53

-54

115%

165%

7–40

0.60–3.00

0.16–0.80

121

90%

138%

3–13

0.33–1.10

0.07–0.30