what happens when a transformer loses its connection with earth?

Answer 1

Are you talking about Distribution transformers ? Then that 3-phase transf. becomes free floating, which means the 'nutral' line receives ALL the phases WITHOUT nutralising them to the Earth reference potential (Standard 0 volts) and hence all the SINGLE PHASE equipment connected to power will experience the 3-phase voltage (up to 440 volts) rather than single phase (about 230 volts). You know what it will do. In case of single phase transformers, and looking at most common load-connection configurations, not much will happen. But you may find more interference on the electronic equipment connected to it.

Answer 2

In theory the system will continue to work ok with no earth connected. However in some situations it is dangerous as the voltage difference between the neutral and ground and the phase and ground could be anything, 100 200 300V etc.
Transformers in bathrooms are used(isolation transformers) with a 1:1 turns ratio (240V in 240V out and no earth connected on the secondary. this is done intentionally in order that the electric has no return path. in larger systems this is not practical.
In domestic properties loss of earth can cause fires as the neutral voltage rises above earth and any earth faults within the installation create a path to earth. Also danger of electric shock.
quite a lot you could say on the subject star and delta connected transformers, tncs distribution systems and tns systems. domestic property earthing etc.

Answer 3

Hi >
If you mean, say the local sub-station, then a couple of things occur.
At an average sort of distance to a domestic property, the neutral to earth voltage should ideally be zero, but usually around 5-7Vac.
Which is OK, but If the thing totally loses it's earth rod, then that will shoot up a considerable amount, rendering earthed appliances & equipment with a potential difference between the earthed casing and a true earth.
Usually harmless, though.
Just don't fiddle with the power transformer until the earthing is fixed up.
Ouch.

Answer 4

The purpose of the earth connection is for safety. If a transformer looses it's earth connection then there's no path way for any leakage currents to travel, if leakage currents should arise. To come in contact with these leakage currents could be potentially dangers for people and livestock.
If leakage currents arise and there is an earth connection in place a person could still get a shock, but because of the earth connection being in place, it could be the differences in saving the person life.

Answer 5

We used to connect welding transformers to 440 VAC and if we didn't have a ground wire attached, the laminations of the transformer would float to 220 VAC. But if you touched the laminations, the current was so small, you didn't get a shock and your body just grounded it.
From a safety point of view, if the primary should ever short out to the laminations, it could be lethal. The ground wire would ensure that enough current would flow to blow a breaker.

Answer 6

In short terms the output voltage would stay the same but the potential to earth on the output side would rise to whatever the input voltage is, assuming that it is a step down transformer.

Answer 7

You will find one part of the circuit lit up like Blackpool on a Saturday night and another part imitating glow worms?
Exciting for some and costly for others.

Answer 8

It will continue to work but there will be inherent dangers to be near it or touching it.

Answer 9

doesn't it become an electric chair?