Discuss ELCB,s.How do they work? in the Electrical Forum area at ElectriciansForums.net

Status
Not open for further replies.

La Poste

Regular EF Member
Messages
992
Location
South east
I know they are a bit old now but they are still used a lot in countries like Thailand.

As far as I understand it an ELCB would be used on a TT system or where there is a high impedance earth loop.
A remote rod is put down into the ground say outside the property and this is then connected to the properties MET/ earthing/CPC system.

During an earth fault the fault current will try to make its way through the property CPC and then to the rod, the fault current will then try to find its way
through the ground and back to the star point of the transformer.

Because the resistance of the rod is quite large a voltage or volt drop will develop between the metalwork in the house and the rod and when this voltage
rises above say 50 Volts the ELCB will switch off the supply.

Inside the ELCB is a sensing coil that measures the difference in voltage between the metalwork inside the house and the ground rod outside.

Is this correct, is this the best way of looking at it?

Any comments appreciated.

Thanks.
 
OP
La Poste

La Poste

Regular EF Member
Messages
992
Location
South east
I'm guessing inside the ELCB is a coil, a coil that has a certain resistance and when a current flows through that coil a volt drop will appear across it, the more current that flows through the coil the higher the volt drop will be between both ends of the coil.

When the volt drop between both ends of the coil becomes 50 Volts or greater the ELCB will switch off the supply.

Is that correct?
 
Status
Not open for further replies.

Permanent unswitched live colour?

  • Brown

    Votes: 63 67.0%
  • Black

    Votes: 31 33.0%

Electrician Talk

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
Top