Wednesday, April 12, 2017

Energy Meter connection;Single Phase; Three Phase; CT operated Energy meters

In every domestic, industrial and commercial establishment there is need of electricity and for measuring power consumption energy meters are installed in all establishments.

For domestic connections usually direct meters are used means power supply wires are directly connected at input and output is withdrawn from its output and for large and commercial establishments CT operated energy meters are used as direct meters are not feasible to install as size of these energy meters will be very high. It is usually recommended to install CT operated meters if load requirements from energy meters are more than 15 KW.
CT operated meter is most preferable meters in all establishments as they are easy to install and operation is very simple.
In this article we study about installation of energy meters both Houses and as well as commercial and industrial establishments:-

In Domestic connections both single phase and three phase energy meters are used:-

For single phase meters wiring is quite simple there are 4 terminals at the meter, 2 No’s for input power supply and 2 no’s for output power supply. Wiring diagram for installation of single phase energy meter is as below:-


Single Phase energy meter connections



For Three phase Energy meters:-
For installation of these meters there are 12 No.s terminals 6 no.s for three phase power supply at Input and 6 no’s for output power supply .
Connection for three phase energy meters are as below:-


Three Phase energy meter connections

CT operated energy meter installation:-
For installation of CT operated energy meters 1st you have to install CT’s at Input cable as per your load requirements. These energy meters can be used for measurement of consumption for any load only CT’s are required to be selected according to load. As power consumption indicated in energy meter is multiplied by CT ratio of energy meter.
Various Connection diagram for energy meter
(i)                 3 CT, 4 wire connections
(ii)               3 Wire, 2 CT connections
are as below:-

CT Operated Three phase energy meter connections


In these meters there are no output terminals as these energy meters are serving the purpose of measuring the energy consumed in circuit. CT output wires are connected at terminals provided for connections of CT’s and apart from CT connections there are three terminals provided for connections for three phase voltages.
Now after doing all connections CT ratio needed to be entered into energy meter so that energy meter reads the correct power consumption consumed in system. If you don’t enter correct CT ratio then you may not get correct results.
Now after doing all connections and programming in energy meter , energy meter starts working when power supply get charged.
There are energy meters also available where you need not enter CT ratio in energy meters instead energy consumption displayed on energy meter needed to multiplied by CT ratio to arrive at actual consumption.


There are many parameters which can be monitored through these energy meters. There are energy meters available in market which works on 2 Quadrant and 4 quadrant. 4 quadrant meters works on both lead and lag power factors i.e. energy meter reading keeps on increasing in case of lead power factor also. But on the other hand in 2 quadrant energy meters , energy meter works on lag power factor only i.e. these energy meters don’t work in lead power factor.