How to decide supply voltage for electricity connection
When an applicant applies for a new connection then the supply voltage for electricity connection depends on the type of category(like- domestic, commercial, industrial, ptw) and how much load (kw/kva) the new connection is applied for. For example, for a domestic connection of 5 kw load, voltage shall be released at 230 v and single phase. As the sanctioned load of the connection increases, the supply voltage also increases accordingly. All connections above 5 kw are issued at 3 phases. the reason for issuing all connections above 5 kw in 3 phases is the load(in ampere) should remain the same on each phase R Y B. Hence, the grid also has the same load across every three phases R Y B.
Benefits of 3 phase connection
The benefit of a three-phase connection is that by using 3 phase supply you to split a load of a house in a setup into every three phases (R Y B). If there are three air conditioners in a house, for example, each should be installed on one of the phases, without overloading any one phase. If one of the phases fails due to any electrical point malfunction, the remaining two phases continue to work. Due to which a complete breakdown of supply could be prevented. So in a house, if there is 3 phase supply then if one phase goes from the transformer only a few parts of the housing supply shall be disturbed and the rest of the supply shall be continued.
The frequency range of supply-
The electricity department shall be responsible for maintaining an uninterrupted electricity supply at a frequency between 49.02 and 50.5 Hz, which is the also frequency range for operation of the national grid which is decided Central Electricity Regulatory Commission.
The supply voltage for electricity connection
When an applicant applies for connection then on what voltage connection will be released it depends on the types of category and load of new connection applied.
First, we will see types of voltage on which supply is used to be released in the electricity department. these voltages of the AC supply shall be as follows:
(1) Low Tension (LT) –
- in case of Single Phase: 230 volts between phases and neutral.
- In case of Three Phase: 400 volts between phases.
(2) High Tension (HT) –
Always in Three-Phase: 6.6 KV / 11KV / 33 KV. For ongoing Railway Traction supply shall be single-phase at 25 KV.
(3) Extra High Tension (EHT) –
Three Phase: 66 KV / 132 KV / 220 KV.
Two-Phase at 132 KV / 220 KV for ongoing Railway Traction.
The Licensee, unless the technical conditions of the distribution system otherwise permit, shall give supply at a voltage and phase indicated as below:
Category & Supply Voltage-
When an applicant applies for a connection then, for what category and load what will be voltage for supply shall be as follow-
(i) Low Tension
(a) load less than 5 KW – Single phase at 230 V and below 5 kw –
All type of category ( light and fan, Domestic connection, Commercials, Private Tube wells and Pump sets(1 HP and 3 HP load) with a contracted load less than 5 KW – Single phase at 230 V
(b) 3 Phase, 4 wire at 400 V and 5 kw above connection–
Private Tube wells and Pump sets and all category connection (domestic and commercial connection) with a contracted load of 5KW or more and up to 50 KW / 56 KVA – 3 Phase, 4 wire at 400 V
(ii) High Tension connection
(a) 3 Phase at 6.6 / 11 KV above 56 kva connection– all category connection with a Contracted load exceeding 56 KVA and up to 3000 KVA – 3 Phase at 6.6 / 11 KV]
(b) 3 Phase at 33 KV above 3000 kva connection – all category connection with a Contracted load exceeding 3000 KVA and up to 10000 KVA – 3 Phase at 33 KV
(iii) Extra High Tension
3 Phase at 132 / 220 KV – all category connection including railways traction with a Contracted load exceeding 10000 KVA – 3 Phase at 132 / 220 KV
So from here applicant /consumer can get full knowledge regarding voltage supply according to his category and load(kw).