Identify the figures and explain their use.
Answers
The figure seems to be of a FUSE
The first is a broken fuse as u can see a small separation b/w wires in middle
The 2nd is a working fuse
FUSE is a safety device which prevents appliances from getting damaged due to fluctuations in voltage. It does so by breaking the circuit (the wore inside gets heated and gets apart, breaking the circuit)
Answer:
1. Safety
Overcurrent protective devices that have tripped are often reset without first investigating the cause of the fault. Electromechanical devices may not have the reserve capacity to open safely when a second or third fault occurs. When a fuse opens it is replaced with a new fuse, so the protection level is not degraded by previous faults.
2. Cost-effective
Fuses typically are the most cost-effective means of providing overcurrent protection. This is especially true where high fault currents exist or where small components such as Control Transformers or DC power supplies need protection.
3. High interrupting rating
With most low voltage current limiting fuses (< 600 volts) having a 200,000 amp interrupting rating, you are not paying a high premium for a high interrupting capacity.
4. Reliability
Fuses have no moving parts to wear out or become contaminated by dust or oil.
5. Component protection
The high current limiting action of a fuse minimizes or eliminates component damage.
6. Extended protection
Devices with low interrupting ratings are often rendered obsolete by service upgrades or increases in available fault current.
7. Selectivity
Fuses can be easily coordinated to provide selectivity under both overload and short-circuit conditions.
8. Minimal maintenance
Fuses do not require periodic recalibration as do some electromechanical overcurrent protective devices.
9. Long life
As a fuse ages, the speed of response will not slow down or change. It’s ability to provide protection will not be adversely affected by the passing of time.