Summary of the SLT earth connection diagram

 

Summary of the SLT earth connection diagram

summary of the SLT earth connection diagram
The earth connection diagram defines the method of earthing the neutral point of a distribution transformer and the user-side earths to ensure protection of people and equipment against insulation faults.

there are 5 different neutral regimes namely:
isolated neutral
resistance grounding
low reactance grounding
earthing by compensating reactance (due to the capacitive effect of HV lines)
direct earthing (not used on European networks)

an earth connection diagram is characterized by two letters. The first indicates the transformer neutral connection, it can be:

T for earthed
I for isolated (or impedant) with respect to the earth.

The second letter indicates the way of connecting the masses of users, it can be:

T for earthed
N for connected to neutral, which is connected to earth.

TT earth connection diagram

.

this connection is used by ONE for public low voltage distribution
the transformer neutral is earthed via an earth electrode with resistance Rn
all the earths of the equipment protected by a same protection device must be interconnected and connected by a protective conductor named PF to a same earth socket

TN-C earth connection diagram

.

TN-S earth connection diagram

.

IT earth connection diagram

.

TN-C-S earth connection diagram

.

 

Summary of the SLT earth connection diagram

summary of the SLT earth connection diagram
The earth connection diagram defines the method of earthing the neutral point of a distribution transformer and the user-side earths to ensure protection of people and equipment against insulation faults.

there are 5 different neutral regimes namely:
isolated neutral
resistance grounding
low reactance grounding
earthing by compensating reactance (due to the capacitive effect of HV lines)
direct earthing (not used on European networks)

an earth connection diagram is characterized by two letters. The first indicates the transformer neutral connection, it can be:

T for earthed
I for isolated (or impedant) with respect to the earth.

The second letter indicates the way of connecting the masses of users, it can be:

T for earthed
N for connected to neutral, which is connected to earth.

TT earth connection diagram

.

this connection is used by ONE for public low voltage distribution
the transformer neutral is earthed via an earth electrode with resistance Rn
all the earths of the equipment protected by a same protection device must be interconnected and connected by a protective conductor named PF to a same earth socket

TN-C earth connection diagram

.

TN-S earth connection diagram

.

IT earth connection diagram

.

TN-C-S earth connection diagram

.