Mell Why must a transformer neutral be grounded?
Neutral earthing resistors are used to limit the fault current in transformers When a phase to earth occurs, the fault current is limited only by the soil resistance. This current, which can be very high, can damage the windings.
Should neutral be connected to ground?
No, the neutral and ground should never be wired together. This is wrong, and potentially dangerous. When you plug in something in the outlet, the neutral will be live, as it closes the circuit. If the ground is wired to the neutral, the ground of the applicance will also be live.
Why do you ground the secondary side of a current transformer?
Secondary grounding of current transformers To prevent the secondary circuits from attaining dangerously high potential to ground, these circuits have to be grounded. Connect either the S1 terminal or the S2 terminal to ground. For protective relays, ground the terminal that is nearest to the protected objects.
Do you have to ground a transformer?
It is necessary to keep the grounded (neutral) conductor separated from the metal parts of equipment, except as required for service equipment and on transformers. Making the proper neutral-to-case connections is the key. Consequences of improper neutral-to-case transformer grounding connections.
What happens if you connect neutral to ground?
If the neutral breaks, then plugged in devices will cause the neutral to approach the “hot” voltage. Given a ground to neutral connection, this will cause the chassis of your device to be at the “hot” voltage, which is very dangerous.
Can neutral and ground be on same bar?
If the main service panel happens to be the same place that the grounded (neutral) conductor is bonded to the grounding electrode, then there is no problem mixing grounds and neutrals on the same bus bar (as long as there is an appropriate number of conductors terminated under each lug).
Are current transformers grounded?
The single grounding of current transformers eliminate the problems of the voltage generated at different ground points of the current transformer. The secondary of the CTs must be grounded at a single point.
Why is PT primary grounded?
Neutral point of primary is solidly earthed. If primary neutral is not earthed the zero sequence component of voltages (due to earth fault) cannot flow through primary windings. Hence the earth fault on system cannot be sensed on secondary side of VT.