Abuja Electricity Distribution Company (AEDC) says the report by the Transmission Company of Nigeria(TCN) that one of its feeders caused the fire incident on Sunday at TCN ‘s Apo Transmission Station is incorrect.
AEDC’s General Manager, Corporate Communications, Mr Fadipe Oyebode, in a statement on Tuesday said the claim by TCN was against any known engineering practice.
The Apo Transmission Substation was engulfed with fire on Sunday afternoon, destroying a 45MVA Power Transformer and several other transmission equipment.
TCN had in press statement claimed that the incident was caused by AEDC’s feeder at the substation, noting that the feeder had a history of trippings.
Fadipe, however, said “We are saddened, instead of doing a root cause analysis of the immediate and remote causes of the fire outbreak, which destroyed an expensive and critical asset with the intention of preventing a re-occurrence. “
“TCN has resorted to a blame game with a defence that is not in tune with standard engineering practice.
“The basic engineering explanation is that, whereas the 33kV line belongs to AEDC, the protection system at the source belongs to TCN.
“For a transformer to go up in flames, both the line and transformer protection apparatus belonging to TCN failed completely.
“ It is the reason for the total failure of their protection architecture that should be investigated.
“The transformer that caught fire belongs to TCN, the protection apparatus is in the custody and under the maintenance and ownership of TCN.
“In any power system all over the world, tripping from outgoing circuits of feeders as a result of fault is an expected component of operations.
“Hence elaborate protection system is provided for such transformers against faults from outgoing feeders.
“These basic protection schemes are expected to fence the transformer from internal and external faults that usually occurs while in circuit.
“For such a facility, there are four levels of protection, there is the protection at the feeder level of feeder H13 accused of causing the fire and property of AEDC.
“ The 2nd level of protection is the protection that exists on the 33kV incomer ,property of TCN and this exists between the secondary side of the transformer and the busbar in the control room of TCN.
“The 3rd level of protection which is in-built in the transformer are of various types and they include winding temperature.
“Others are oil temperature, pressure relief, buckholz, standby earth fault and restricted earth fault,this is also within the control of TCN.
“The fourth level of protection for such a facility is the protection on the 132kV side of the 45MVA, 132/33kV side of the transformer.
“ This is also under the control of TCN, of the four levels of protections, three of them which are the most critical are owned, controlled and maintained by TCN.
“The essence of these multilayer protection schemes is to ensure that where one of the protection devices fail, the others will come to the rescue of the electrical apparatus.
“But in the logic of TCN, failure of one is the failure of others whereas the activation and performance of the other three, under its control is not dependent on feeder H13 alleged to have triggered the fire incident.’’
Fadipe commended the Fire Service of the NNPC and FCT for saving AEDC customers from what could have been a calamity of immense proportion.
Fadipe said AEDC would continue to invest in its network to provide customers with world class service.
He called for a complete overhaul of the protection architecture of TCN’s facility at the Apo and and other substations within AEDC’s coverage areas.(NAN)