Why should a safety ground have very low impedance?

So fault current is large enough to trip the fuse/breaker quickly

So it carries signal return current

So it limits fault current to a tiny value

So it isolates the chassis from earth

How much current does a safety ground carry in normal operation?

None; it conducts only during a fault

Which is a proper characteristic of a safety ground path?

Continuous, with no switch or fuse in the path and adequate conductor size

Thin conductor to limit current

2071 Chaitra · 2 marks

Characteristics of a safety ground

Short answer

A safety ground is a low-impedance (<1 Ω) path connecting exposed metal parts to earth, carrying no current normally but enough fault current to trip protection. It must be reliable, continuous, with adequate ampacity, and isolated from signal returns.

What are the characteristics of a safety ground?

A safety ground is a path that carries fault current to earth to protect people and equipment from shock. Its characteristics:

Very low impedance (resistance, typically below 1 ohm) so that a fault current is large enough to trip the fuse/breaker quickly.
Connected to earth and to exposed metal parts (chassis, enclosure) of the equipment, normally via the green/yellow earth wire.
Carries no current in normal operation; it conducts only during a fault.
Adequate current capacity (thick conductor) to carry the maximum fault current without melting.
Continuous and reliable: no switch or fuse in the path, with secure mechanical connections.
Not shared with signal returns, to avoid injecting noise into the circuits.

✓ Answer checked by Claude Sonnet 5.5

Ionosphere structure and ground wave · Propagation and Antenna, chapter 4
Radio wave types and band characteristics · Propagation and Antenna, chapter 4 · asked 2×

All Instrumentation II chapter 6 questions →

Characteristics of a safety ground

Related questions