1. Reasons you might not be having light
Defined below are Engineering terms for comprehensive and professional
digestion;
-Operator: The qualified man (Engineer) that closes and opens feeders in a Control
Room.
- Injection Substation: A structure or building from which Control Room is created.
- Control Room: The room housing the Feeders and the Operator.
-Feeder: Electricity source of the Substation (Transformer) on your street from the
Control Room.
-Substation: Transformer on your street.
-Line: The path (Wire) along which Electricity travels from the feeder to your
Substation (Transformer).
-Relay: A part of the feeder that serves as eyes. It gives/shows reason(s) of trip
when there is/are fault(s).
-Trip: Feeder opening due to normal or abnormal situation as a result of either external
or internet fault(s)
- Power Transformer: This is the transformer at the Injection Substation from which
Feeders feeding Transformers (Substations) receive supply.
-Opening: Switching off
-Closing: Switching on
-Load shedding: Sharing of Electricity among consumers on 2 or more Feeders with a
common Power Transformer.
-Local load shedding: Sharing of Electricity among consumers on 1 Feeder.
Please, you should know that no Operator derives pleasure in Closing and Opening of
Feeder. Operators do not have time and supposed energy for that. So, stop cursing and
abusing when your light keeps going on and off within minutes. The Operator is only
making effort you have light.
Besides, it is against the code of conduct of an Operator to close a Feeder
after tripping if he hasn't informed the linesmen to patrol and locate area of
fault and make amend.
Constant operation of Feeder is said to wear out the spring thereby resulting to
replacing or repairing or managing (this also takes efforts in operating).
Here are few main reasons why you might not have been having light.
1. Load Shedding And Local Load Shedding:

2. (Note: Among reasons, this is the most important you need to understand clearly. I'm
going to take my time explaining this)
Load Shedding (L/S) happens when power needs to be shared among consumers on
a Building, Street, Neigbourhood, Local Government, State or Country as the case may
be in order to relief the related Transformer from overloading. We can simply call Load
Shedding “Damage Control” operation.
Case study:
An Injection Substation (Control Room) with Power Transformer of 15MVA has 4
Feeders. Namely;
Feeder 1 (Lagos)
Feeder (Anambra)
Feeder (Kano)
Feeder (Ogun)
-Lagos has 10 Substations (Transformers) with total sum capacity of 12MVA. And
let's assume Lagos consume about 8MVA on full load (i.e. Lagos consumes less than
the Transformers’ summed capacity)
-Anambra has 15 Substations (Transformers) with the total sum capacity of
17MVA. And let's assume Anambra consumes about 17MVA on full load (i.e. Anambra
consumes equal to the Transformers’ summed capacity)
-Kano has 25 Substations (Transformers) with the total sum capacity of 5MVA.
Let’s assume Kano consumes 5MVA on full load (i.e. Kano consumes equal to the
Transformers’ summed capacity)
-Ogun has 7 Substations (Transformers) with the total sum capacity of 7MVA.
While Ogun consumes only 1MVA on full load (i.e. Ogun consumes far less than
Transformers’ summed capacity)
N.B: A transformer shouldn't be operated on 100%, but 75% capacity as
factor of longevity.
But, let's assume all Transformers here work on 100% full load capacity.
Summary:
-Injection S/station Power Transformer: 15MVA
-Lagos: 12MVA (Consumes 8MVA)
-Anambra: 17MVA (Consumes 17MVA)
-Kano: 5MVA (Consumes 5MVA)

3. -Ogun: 7MVA (Consumes 1MVA)
Note: The sum of total consumption by States must not exceed 15MVA of the
Injection Sub-station’s Transformer to avoid damage or tripping as a result
of Over-load.
Since Anambra (17MVA) consumes more than Injection Substation Power Transformer
of 15MVA, then LOCAL LOAD SHEDDING is going to be employed on the Feeder to
avoid damage or trip on the Injection Substation Power Transformer due to over-load.
At this point, some Substations (transformers) will be out of service.
This is a major reason you see some parts of your neighbourhood having
light when you have not, and vice versa
This method is also applicable in Area that consumes more than the summed
substations (transformers) supplying the Area.
A case study of an Area consuming 20MVA when the summed capacity of the
substations (transformers) supplying the Area is 10MVA. This means that at least
10MVA load must be dropped so as to balance the grid so as to avoid damage of
substations (transformers)
These are possibilities of operations on per day schedule;
(Giving out 15MVA)
After Anambra has been Locally load-shedded to 10MVA.
-Lagos (8MVA) + Ogun (5MVA) + Kano (1MVA) = 14MVA
-Anambra (10MVA) + Kano (5MVA) = 15MVA
Days Of Enjoyment On Each Feeder.
-Lagos: 3-4 days a week
-Anambra: 3-4 days a week, while local load-shedding goes on. It means some parts
will have supply for 2-3 days a week.
-Ogun: 3-4 days a week
-Kano: 7 days a week
Note: Kano enjoys more supply because it has the lowest consumption rate,
as Anambra suffers more as a result of Load Shedding and Local Load
Shedding it suffers from.
2. Bypassing:

4. Like the happenings in some states, some Distribution Companies have decided to stop
giving constant power supply due to shortage of revenue. Customers bypassing Pre-
paid meter. Hence, consume more than they pay for.
What is the essence of the Company paying much when profit is not maximized.....they
are still looking into the matter.
Note: Distribution Company pays Transmission Company (TCN), and
Transmission Company (TCN) pays Generation Company.
3. System collapse:
This could be as a result of fault from Injection Substation or from TCN Station or from
Generation Station (e.g. Shiroro)
4. Devil-May-Care Attitude:
Carelessness over the state of supply in your environment by not reporting to a nearby
office if supply deteriorates. The efficiency and togetherness of the landlords and
landladies go a longer way in this regard.
5. Damage:
Cases of Earth Fault, Over Current, Line-cut, dropped J&P, damaged fuse, damaged
transformer, and the likes which could be due to vandalism, weather factor, etc
6. Unit Exhaustion:
Running out of Unit without knowing
7. Disconnection:
Termination of service cable as to non-remittance of bill.
8. Violence:
Fighting the officials on patrol, especially those conducting disconnection and. This
could lead to black-out punishment.
You are free to add yours and ask questions.