Eng. B. M Solutions

Eng. B. M Solutions EPRA C1 | EPRA T3
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đź‘· Electrical Engineer & Consultant
âś… Power & Backup Solutions Specialist
✅ UPS • Inverters • AVRs
âś… Solar PV Design & Consultancy
âś… Protection, LV boards & Control Panels
âś… Data center power infrastructure specialist.

WHAT HAPPENS WHEN A TRANSMISSION LINE TOUCHES THE GROUND?A fallen transmission conductor is extremely dangerous — even i...
24/09/2026

WHAT HAPPENS WHEN A TRANSMISSION LINE TOUCHES THE GROUND?

A fallen transmission conductor is extremely dangerous — even if there are no sparks.

When an energized conductor contacts the ground, a ground fault occurs. Large fault current can flow from the conductor into the earth and back through the grounding system, depending on the system configuration and fault impedance.

🚨 But the danger doesn't stop at the contact point.

The current spreading through the soil creates different voltages at different points on the ground. This is called ground potential rise.

That means two points on the ground can have different voltages.

đź‘Ł Step potential:
If you stand near the fault with your feet separated, each foot can be at a different voltage. Current can then flow through your body from one foot to the other.

That's why you should NOT run away from a fallen power line.
Move away by shuffling with very small steps, keeping your feet close together, or hop away if necessary.

What happens on the grid?

Protection systems detect the fault using devices such as overcurrent and earth-fault protection. The associated circuit breaker should trip and disconnect the faulty line.

However, never assume the line is dead just because the breaker has tripped. Automatic reclosers may attempt to re-energize the line, and the conductor can remain dangerous.

👉 Stay far away, warn others, and contact the electricity utility/emergency services. Never approach or touch the conductor.

One fallen transmission conductor can make the surrounding ground dangerous. Electricity doesn't need to visibly spark to be deadly.

Cable management Eng. B. M Solutions
21/09/2026

Cable management
Eng. B. M Solutions

UPS Installation – ATM UPS installation completed for the ATM to provide backup power and ensure uninterrupted operation...
21/09/2026

UPS Installation – ATM UPS installation completed for the ATM to provide backup power and ensure uninterrupted operation during power outages.

WHAT REALLY HAPPENS AT THE NATIONAL GRID CONTROL CENTRE?Ever wondered how Kenya keeps millions of electrical loads suppl...
19/09/2026

WHAT REALLY HAPPENS AT THE NATIONAL GRID CONTROL CENTRE?

Ever wondered how Kenya keeps millions of electrical loads supplied with power every second?

The National Grid Control Centre is essentially the control room for the electricity transmission system.

Here, operators continuously monitor and manage the grid, including:

🔹 Generation – They monitor how much power is being produced by hydro, geothermal, wind, thermal and other generating plants.

🔹 Power flows – They monitor how electricity is flowing through transmission lines and substations and watch for overloaded equipment.

🔹 Frequency – Grid frequency must remain close to 50 Hz. A major imbalance between generation and demand can cause frequency to rise or fall.

🔹 Voltage – Operators monitor transmission voltages and coordinate actions to keep them within acceptable operating limits.

🔹 Circuit breakers & equipment – The control centre receives information from substations and can remotely operate certain grid equipment when required.

🔹 Faults & alarms – If a transmission line, transformer or other equipment trips, alarms immediately alert operators, who assess the situation and coordinate restoration.

🔹 Generation–load balance – Electricity cannot simply be stored in the transmission grid. Generation must continuously match demand.

🔹 System security – Operators study changing grid conditions and coordinate switching, generation dispatch and other actions to prevent disturbances from spreading.
In simple terms:
👉 Power stations generate the electricity.
👉 Transmission lines move it.
👉 Substations transform and switch it.
👉 The National Grid Control Centre monitors and coordinates the whole system.

It's basically the "control room" of the national electricity network.

NO BRUSHES, NO SPARKS! — HOW DOES A BRUDHLESS DC MOTOR WORK?A Brushless DC (BLDC) motor does something interesting: it p...
18/09/2026

NO BRUSHES, NO SPARKS! — HOW DOES A BRUDHLESS DC MOTOR WORK?

A Brushless DC (BLDC) motor does something interesting: it produces continuous rotation without brushes or a mechanical commutator.

1. DC power enters the controller
The DC supply is switched electronically by an inverter/controller, which creates the required current sequence in the motor windings.

2. The stator creates a rotating magnetic field
The stator has coils. By energizing these coils in the correct sequence, the controller creates a rotating magnetic field.

3. The permanent-magnet rotor follows the field
The rotor contains permanent magnets. It continuously tries to align with the rotating magnetic field, producing torque and rotation.

4. Electronic commutation replaces brushes
In a brushed DC motor, brushes and a commutator switch the winding current mechanically.
In a BLDC motor, semiconductor switches do this electronically.

5. How does the controller know when to switch?
It can use Hall-effect sensors, or in sensorless designs, it can estimate rotor position from electrical signals such as back EMF.

THE BIG IDEA:

DC supply → electronic controller → sequentially energized stator windings → rotating magnetic field → permanent-magnet rotor follows → rotation.

That is why BLDC motors generally have less mechanical wear, no brush sparking, and high efficiency compared with conventional brushed DC motors.

đź’¬ Question: If there are no brushes, what actually performs the commutation?

POWER LINE FALLS NEAR YOU? DON’T RUN!A fallen high-voltage line can send fault current into the ground, creating a volta...
16/09/2026

POWER LINE FALLS NEAR YOU? DON’T RUN!

A fallen high-voltage line can send fault current into the ground, creating a voltage gradient around the point of contact.

This means two points on the ground can be at different electrical potentials — a danger known as STEP VOLTAGE.

⚠️ The line will also produce a strong magnetic field when carrying current, but the magnetic field itself is not the main cause of the step-voltage hazard.

If you are already close to the fallen line:

🔹 Never touch the conductor — assume it is LIVE.
🔹 Keep your feet together and shuffle away using small sliding steps.
🔹 Do NOT run or take large steps — this increases the voltage difference between your feet.
🔹 If shuffling is impossible, hopping away on one leg can reduce the distance between your contact points with the ground, but be extremely careful not to fall or put the other foot down.
🔹 Stay away from poles, fences, trees, vehicles and other conductive objects that may be energized.
🔹 Once safely away, keep others away and report the line to the electricity utility/emergency services.

WHY SHUFFLE?

The smaller the distance between your feet, the smaller the potential difference that can be applied across your body.

🚨 A fallen power line is never “just a wire on the ground.” The ground itself can become part of the electrical circuit.

Stay away. Keep your feet together. Let qualified personnel make it safe.

16/09/2026

If your electrician’s price is your first concern, safety probably isn’t your first concern

WHY DO OVERHEAD POWER LINES SAG? — AND WHY DOES CLEARANCE MATTER?An overhead conductor is not installed perfectly straig...
16/09/2026

WHY DO OVERHEAD POWER LINES SAG? — AND WHY DOES CLEARANCE MATTER?

An overhead conductor is not installed perfectly straight. It naturally forms a curve between two supporting structures.

🔹 1. SAG

Sag is the vertical distance between the conductor's support level and its lowest point.

Why is sag necessary?

âś…Temperature: When a conductor heats up, it expands and sags more.
âś…Current: Higher current can increase conductor temperature and therefore sag.
âś…Wind & ice: Environmental loading can change the conductor's position and tension
Mechanical tension: Increasing tension reduces sag, but excessive tension can overstress the conductor and structures.

🔹 2. CLEARANCE

Clearance is the minimum safe distance between the conductor and something else—such as:

Ground
Roads
Buildings
Trees
Other electrical circuits

As the conductor sags, ground clearance decreases. Therefore, lines must be designed for the maximum expected sag, not just how they look on a cool, calm day.

🔹 3. SPAN / INTERVAL

The span is the horizontal distance between two consecutive supports.

Generally:

Longer span → greater sag for the same conductor and tension.

But making the span shorter means more towers/poles and therefore higher construction cost.

So engineers have to balance:

Safety + conductor tension + sag + clearance + structure cost.

CAN THE NEUTRAL CONDUCTOR BE SMALLER THAN THE PHASE CONDUCTORS?Yes — but only under specific conditions.Many people beli...
15/09/2026

CAN THE NEUTRAL CONDUCTOR BE SMALLER THAN THE PHASE CONDUCTORS?

Yes — but only under specific conditions.

Many people believe the neutral must always be the same size as the phase conductors. That is not always true.

For a three-phase circuit, the neutral can be reduced in size when the load is sufficiently balanced and the neutral current is demonstrated to be within the safe current-carrying capacity of the smaller conductor.

Under IEC 60364-5-52:2024, for example, where the phase conductors are larger than 16 mm² Cu or 25 mm² Al, a reduced neutral may be permitted provided the required conditions are met, including:

🔹 The load is balanced between phases.
🔹 Third-harmonic and other triplen harmonic currents are sufficiently low.
🔹 The reduced neutral is adequately protected against overcurrent.
🔹 The neutral is still at least 16 mm² Cu or 25 mm² Al and generally not less than 50% of the phase conductor size under the stated provision.

⚠️ But harmonics can change everything.

In buildings with many electronic loads—such as UPS systems, computers, LED lighting and other non-linear loads—third-harmonic currents can add together in the neutral instead of cancelling. The neutral can therefore carry a very high current, sometimes higher than the phase current.

So don't reduce a neutral simply because the three phases are balanced.

Correct principle: Size the neutral according to the actual expected neutral current, including harmonics, and the applicable installation standard—not by guesswork.

Single-phase circuits: the neutral is generally required to be the same cross-sectional area as the phase conductor.

A smaller neutral can be compliant. An undersized neutral is not.

WHY GRID TIED SOLAR SYSTEM SWITCH OFF WHEN UTILITY POWER GOES OFF?You have solar panels producing electricity, so why ca...
14/09/2026

WHY GRID TIED SOLAR SYSTEM SWITCH OFF WHEN UTILITY POWER GOES OFF?

You have solar panels producing electricity, so why can’t a grid-tied solar system continue powering your house during a blackout?

The answer is anti-islanding protection.

A grid-tied inverter is designed to work in synchronization with the utility grid. It continuously monitors the grid’s voltage, frequency and other conditions.

When the grid fails, the inverter detects the abnormal condition and disconnects from the grid automatically.

WHY?

Imagine a power line has been switched off for maintenance. If your solar inverter continued feeding electricity into that line, it could energize the supposedly dead network.

That creates a serious safety hazard for utility workers and can also cause problems when grid power is restored.

So the inverter is required to stop exporting power when the grid is no longer present.

BUT THE SUN IS STILL SHINING!

Yes! The panels may still be producing DC power.

The problem is that a normal grid-tied inverter is not designed to create and maintain its own independent AC grid. It needs the utility grid as its reference for synchronization.

Want solar power during blackouts?

You need a properly designed hybrid/off-grid system, typically with battery storage and the necessary switching/islanding protection, so the inverter can safely create a local supply when the utility grid is unavailable.

So remember: Solar panels can produce power during a blackout—but a standard grid-tied inverter will normally shut down to prevent dangerous islanding.

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