A fuse in a neutral safety switch is there to protect the circuit from overloading. If the switch were to malfunction and allow too much current to flow, the fuse would blow and break the circuit, preventing further damage.
Full Answer
What is a fuse neutral?
A single fuse in the phase conductor provides protection for both kinds of faults. A single fuse in the neutral conductor provides protection for neutral-to-phase faults, but not for phase-to-ground faults. This is one reason why a single fuse in the neutral is not permitted.
Why do we not fuse the neutral?
If it is connected to neutral wire, the fuse will melt when excess current flow, but the appliance will still be connected to high potential through live wire. Thus, if a person touches the appliance, he receives shock.
Do you fuse a neutral in disconnect?
In order to avoid only the neutral being disconnected, it must never be protected by a fuse. Equally, the neutral conductor will not be disconnected automatically if a fuse on one of the phases blows.
Is live or neutral fused?
Fuse is always connected to a live wire. If fuse wire is connected to neutral wire instead of live wire then even when the fuse burns out the appliance remains connected to the live wire and the current supplied will not be disrupted due to overloading.
Can I fuse the neutral wire?
Watch out: it is unsafe to fuse the neutral wire in addition to or rather than the "hot" wire in an electrical circuit because an over-current may blow the "neutral" fuse while leaving the circuit's hot or feed side wire electrically live.
Why a switch is connected in phase wire and never in neutral wire?
If the switch or fuse is placed in the neutral wire, the electrical appliance is still connected to the high voltage live wire even when the switch is open, or the fuse is blown. This could cause the user to get an electric shock if they touched the inside of the appliance.
Can you switch a neutral in a disconnect?
For most applications there is no requirement to break the neutral with the disconnect switch. If you do break it, it must be simultaneously or after the ungrounded conductors are opened, as well as simultaneous or first make when closing the switch.
Does main breaker disconnect neutral?
All "low power" circuit breakers must interrupt the live wire. Only "high power" circuit breakers interrupt both live and neutral.
Is a neutral allowed to be switched?
Wiring for 3-way and 4-way switching must be done so that only the ungrounded conductors are switched [404.2(A), as shown in the Figure below. In other words, the neutral conductor must not be switched.
Should fuse be on hot or neutral?
In the US if you fuse or switch only one wire it has to be the hot wire.
Where do we connect a fuse with live or neutral wire?
(l) A fuse is connected to the live wire.
Which wire is live neutral?
The live wire of domestic circuits is usually red and is at high voltage. The neutral wire is black and has voltage close to that of the ground. The potential difference between these two wires in India is about 220 V. The earth or ground wire provides safety against faults and current leaks.
Why is a fuse connected to the live wire instead of neutral wire in a 3 pin plug?
Fuses must be fitted onto the live wire so that when it blows, it will disconnect (isolate) the appliance from the high voltage live wire. (If the fuse is placed in the neutral wire, the electrical appliance is still connected to the high voltage live wire even when the switch is opened.)
Why fuse is always connected in phase wire?
A fuse is a circuit element made of highly resistance material such that melts when there is overloading in the circuit. It is always connected in the live wire as to break the circuit preventing the connected devices from damage.
Why is a switch connected to the live wire?
The switch should always be connected to the live wire so that when it is off, no current flows through the appliance. If it is connected to the neutral wire, the circuit always remains on even when it is off.
Is potential of live and earth wire same?
The live wire of domestic circuits is usually red and is at high voltage. The neutral wire is black and has voltage close to that of the ground. The potential difference between these two wires in India is about 220 V. The earth or ground wire provides safety against faults and current leaks.