Circuit breakers are an essential safeguard to electrical systems, but they can be vulnerable to mechanical damage. When a circuit breaker trips to open the circuit, the arm that carries the contact can move violently due to magnetic repulsion forces. The moveable contact can over-travel or bounce back, causing damage. Circuit breaker builders typically incorporate shock absorber elements into their designs to address the problem. Here’s how one manufacturer uses an ACE Controls miniature shock absorber in a circuit breaker design to dampen the impacts:
The circuit breaker — which will open in various emergency situations — operates in a medium voltage range between 7.2 and 38 kilovolts, and the lever’s impact speed is 4.25 feet per second. In this particular unit, the shock absorber is used to reduce forces over a wide and low temperature range.
The manufacturer chose an ACE Controls SC300-3 miniature shock absorber, part of the SC190 to SC925 product family. The “SC” stands for “soft contact,” which is made possible by the damper’s 0.75-inch long strokes. It features an energy capacity of 300 inch-pounds per cycle, and it can handle impact velocities from 0.5 to 12 feet per second. These self-compensating shock absorbers react to changing energy conditions without adjustment. SC190 to SC925 product family features and specifications include:
- Overlapping effective weight ranges, covering loads of 3 to 4,400 pounds.
- Units can be set up with a linear or a progressive braking curve.
- Impact angles up to 25 degrees using a side load adapter.
- Integrated positive stop.
- Maintenance-free and ready to install.
Using the SC300-3 miniature shock absorber, the circuit breaker manufacturer was able to achieve smooth arcing and bounceback at the end of an opening operation whenever fault conditions occur. And thanks to the shock absorber’s wide operating temperature range of 32 to 150°F, the shock absorber functions reliably in harsh temperatures.
Ensure a Safe, Functional Electronic System
Because circuit breakers are critical to keeping electronic systems safe and functional, people and personnel must have confidence in their reliability. A damaged circuit breaker due to over-travel and bounce-back issues is unacceptable. The ACE Controls SC190 to SC925 shock absorber family exhibits low reaction forces and provides smooth deceleration to ensure circuit breakers operate reliably over a long lifetime.
For more information about the ACE Controls SC190 to SC925 family of soft-contact miniature shock absorbers, visit the product page.