An industrial panel uses a cartridge fuse rated at 250V, 32A. If a technician replaces it with a 16A fuse of the same voltage rating, what is the likely outcome during normal operation at 28A?
The fuse will blow even during normal load conditions.
A fuse is a protective device whose thin element melts and breaks the circuit when the current through it exceeds its rated value for a sufficient time; the rating is chosen a little above the normal load current.
Here the circuit normally operates at 28 A, and the original fuse was correctly rated at 32 A, comfortably above the running current so it does not blow in normal use.
Replacing it with a 16 A fuse sets the trip level well below the 28 A working current, so the element carries almost twice its rating during ordinary operation.
At 28 A through a 16 A element the fuse wire overheats and melts, so the fuse blows even under normal load conditions, causing nuisance tripping and loss of supply.
It certainly cannot let the equipment run at higher current safely; a lower rating means less current capacity, not more.
It does not give improved overload protection without drawback, because a fuse that opens during normal running is unusable, and the voltage rating (unchanged at 250 V) has nothing to do with the melting, so no insulation breakdown occurs.
Hence, the answer is The fuse will blow even during normal load conditions.
Similar Questions
L series MCBs can be used effectively in:
Fusing factor of fuse is always
Which component in an MCB is responsible for detecting a short circuit?
- A shunt release in an MCCB is commonly used for:
A single device that ensures efficient protection from electrical hazard of shock and fire caused by over current, short circuit, earth leakage, and earth fault is:
- What is used as a Circuit breaker?
Which component in a wiring diagram is specifically used to protect against overcurrent?
Which statement best describes an isolating switch?
A domestic MCCB is marked 25A, 6 kA, 230V AC. Which fault current will this MCCB safely interrupt?
If an ELCB in a domestic installation trips occasionally without any apparent fault, what could be a probable reason?
Important Questions from Circuit Breakers
L series MCBs can be used effectively in:
Fusing factor of fuse is always
What is one of the functions of circuit breakers in a substation?
- For below 400 KV systems, the circuit breaker is designed to withstand ______above the normal system voltage.
If Ic is the critical current and Zo is the surge impedance, the basic impulse insulation level can be calculated as
