FG Bans Use Of Substandard Transformers, 33KV Feeder Lines To Convey Power From Transmission Substations

MD/CEO NEMSA, Engr.  Peter Ewesor

By CLEMENT NWOJI, Abuja

The Federal Government has banned the use of substandard transformers without the specified vector group just as it insisted that all prepaid meters must be subjected to test before deployment to ensure compliance to standards.

Also banned is the use of 33KV primary feeder lines to convey power from the transmission substation to 33/11 KV injection substation for point load.

The Managing Director of the Nigerian Electricity Management Services Agency (NEMSA), Engr. Peter Ewesor, who disclosed these to Journalists, said that the measures were necessitated by the need to ensure safety of lives and properties.

He cited that the permissible and allowed transformer vector group specifications are contained in the extant Nigeria Electricity Supply and Installation Standards (NESIS) regulations.

According to the regulations, “Standard power Transformers (TSs) capacities shall be 2.5 MVA, 5MVA, 7.5MVA, 15MVA and up to 30MVA suitable for 33/11KV operation with 11KV at secondary side of the transformer, at a nominal frequency of 50Hz and vector group of Dyn1.

“Distribution Transformers shall be 25KVA, 50KVA, 100KVA, 200KVA, 500KVA, 1000KVA, 1500KVA and 2500KVA suitable for 33/0.415KV or 11/0.415KV operation with 400V at secondary side of the the transformer, at a nominal frequency of 50Hz with vector group Dyn11.”

Ewesor who doubles as the Chief Electrical Inspector of the Federation, warned the Ministries, Departments and Agencies (MDAs), electricity contractors and importers to ensure compliance to acquiring the specified standard transformers, adding that no waiver would be granted to anyone who violates the extant regulations.

He explained that a lot of transformers short of the specified standards which are imported into the country are associated with dangers including: overheating of the transformer and other electrical equipment; high energy wastage; generation of harmonics that can distort the smooth flow of power supply and the transformer could explode and cause havoc due to excessive overheating.

On the ban in use of 33KV primary feeder lines conveying power from transmission, the NEMSA Managing Director noted that use unnecessarily increase the line loads on the 33KV feeder lines to the detriment of delivery of bulk power to the 33/11KV injection substations thus the customers on the 11KV/0.415KV network who are in the majority are deprived of adequate and reliable power supply.

Further, he said that the 33KV points load locations are potential fault points along the 33KV primary feeder lines and causes frequent tripping of power lines and power system equipment.

On metering, he urged the electricity consumers to ensure that their meter are tested by NEMSA to avoid the consequences of using such untested/uncertified meters.

The consequences include electrical accidents; possibility of fire outbreak; inaccurate reading of energy supplied and consumed; improper or crazy billing and short life span of the meter, among other consequences.

Stressing that no meter is exempt from being tested before deployment to the consumers, he advised electricity consumers to check for a plastic seal of NEMSA to confirm that their meters had been tested and certified for use.