Its has become imperative that much informations about diesel generator and their simple maintenance techniques and safety tips are so scarce in this platform. So, I decided to be of an helping hand to those who are of need.

Erratic power supply or total darkness in Nigeria is not news any more. Most homes,businesses and manufacturing industries all relied on alternative source of power supply to run their machines. This machine cost lot of money, also, needs adequate attention and knowledge. So,feel free to post your technical questions, enquiery, maintenance tips, overhauling,electrical faults etc here.

PRINCIPLES OF DIESEL ENGINE OPERATION
A reciprocating engine is an internal combustion power unit,in which the heat of burning fuel is converted into work in the cylinder of the engine. In the diesel engine, air is compressed in the cylinder; then, after the air has been compressed, a charge of fuel is sprayed into the cylinder and ignition is accomplished by the heat of compression. The resulting expanding gas provides the force to turn the crank-
shaft.
THE FOUR CYCLE PRINCIPLE
The four piston strokes of the cycle occur in the following
order: Intake, Compression, Power and Exhaust.

1.Intake stroke
During the intake stroke, the piston travels downward, the intake valve is open, and the exhaust valve is closed.The downstroke of the piston permits air from outside to enter the cylinder through the open intake valve port. The turbocharger (when fitted) increases air pressure in the engine intake manifold and forces it into the cylinder. The intake of air is never restricted by carburetion or mixing valves such as those used on spark-ignited, automotive-type The intake charge consists of air only with no fuel mixture.

2. Compression Stroke
At the end of the intake stroke, the intake valve closes and the piston starts upward on the compression stroke. The
exhaust valve remains closed. At the end of the compression stroke, the air in the combustion chamber has been compressed by the piston to occupy a space about one-sixteenth in volume as it occupied at the beginning of the stroke. Thus, the compression ratio is 16:1. Compressing the air into a small space causes the temperature of that air to rise. Near the end of the compression stroke, the pressure of the air above the piston is approximately 470 to 585 psi (3240 to 4034 kPa) and the temperature of that air is approximately 1000 ̊ F (538 ̊ C).
During the last part of the compression stroke and the early part of the power stroke, a small metered charge of fuel is injected in the combustion chamber.Almost immediately after the fuel charge is injected into the combustion chamber, the fuel is ignited by the hot air and starts to burn. By the time the piston reaches the end of the compression stroke, the burning fuel causes a further increase in the pressure above the piston. As the more fuel is added and burns the gases get hotter, the pressure increases, pushing the piston downward and adds impetus to crankshaft rotation.

3. Power Stroke
During the power stroke, the piston travels downward and torque power is translated to the rotating crankshaft through the connecting rods. Both intake and exhaust valves are closed.

4. Exhaust Stroke
During the exhaust stroke, the intake valve is closed, the
exhaust valve is open, and the piston is on its upstroke. Burned gases are forced out of the combustion chamber through the open exhaust valve port by the upward travel of the piston. From the preceding description of the Diesel Cycle, it is apparent that the proper operation of the engine depends upon the two separate functions - first compression for ignition, and, second, that fuel be measured and injected into the compressed air in the cylinder in the proper quantity and at the proper time.

Next we shall talk about normal maintenance check of diesel generator.

DoctorGenerator:
Next we shall talk about normal maintenance check of diesel generator.

NORMAL MAINTENANCE CHECKS
Fuel System
Drive Belts
Battery
Oil Pressure
Coolant Temperature & Level
Crankcase
Running Inspection

Fuel System
Periodically check fuel tank to assure it is full. Keep the fuel tank filled to reduce condensation to a minimum and to assure full running time during emergency operation. Per NFPA 25 specifications the fuel level should never be below 67% of tank capacity. Engine fuel filter should be changed annually or when fouled with contaminations. If contaminated, locate the source and correct. Check the gauze strain-
er of the fuel pump and clean if necessary

Drive Belts
All drive belts should be checked every six months. Belts can be inspected by pressing down the belt with the thumb at the center of the longest free length and check the deflection. With moderate thumb pressure (10 lbs./70kPa) the deflection of the belt should be 3/8"(10mm)

Battery
Check the batteries to insure they are clean and dry, the terminals tight and protected, and the electrolyte must be at the proper level. They should be tested weekly to determine the condition of cells, and the state of charge.

Oil Pressure
Normal engine operating oil pressure is 40-60 psi (276-414kPa). If operating pressure falls below 40 psi (276 kPa), stop engine and investigate cause

Coolant Temperature & Level
When the engine is not running, the jacket water heater maintains the coolant between 120 -140 degrees F (49-60 C). When running, engine coolant temperature should register between 160-200 degrees F (71-93 ̊ C)Coolant levels should be checked weekly by assuring that the level is filled to the bottom of the heat exchanger fill neck. If the level is not there, check for the reason then refill
system.

Crankcase
The oil level should be maintained between the Full mark and Low mark. Check the oil level weekly prior to normal exercise. Do not check oil level when the engine is running.If the engine crankcase was refilled, stop the engine after normal operating temperature has been reached, allow the oil to drain back into the crankcase (approximately 10 minutes) and check the oil level. Add oil, if necessary, to bring
it to the proper level on the dipstick.
NOTE:DO NOT OVER-FILL CRANKCASE.
Use only the recommended lubricating oil.

Running Inspection
While the engine is running at operating temperature, check for coolant, fuel or lubricating oil leaks. If any leaks are observed shut the engine . Correct problem as necessary and re-run engine.

first to comment. Anyway, thanks Op, your thread is very insightful and educative. At least one can learn the basic principles behind diesel engines.

Thanks Op. I wish a saw this last 2 weeks. My generator Perkins, 250kva started changing sounds whenever it's refilled why running. Brings out white smoke, till u shut it down

AnaCheks:
Thanks Op. I wish a saw this last 2 weeks. My generator Perkins, 250kva started changing sounds whenever it's refilled why running. Brings out white smoke, till u shut it down

White smokes occurs when raw diesel comes through the exhaust completely intact and unburned. This can happened with
1. Damaged or faulty injectors
2. Incorrect injection timing, worn timing gear or faulty crankshaft key way
3. Low cylinder compression
4. Water entering the combustion spaces can also cause this.

Sir, your Perkins generator needs intensive mechanical repair.

What do you think about Hyundai 150Rpm diesel generators? Do they have their parts in available in Lagos?

FG Wilson and Mikano 20Kva diesel generators now selling at 3.6 - 3.8 million naira while Hyundai 30kva is being sold for 2.4 million naira and Hyundai 40Kva selling for mere 2.8 Million naira.

Do you think it's safe and sensible to go for Hyundai instead of FG Wilson or Mikano?

DoctorGenerator:


White smokes occurs when raw diesel comes through the exhaust completely intact and unburned. This can happened with
1. Damaged or faulty injectors
2. Incorrect injection timing, worn timing gear or faulty crankshaft key way
3. Low cylinder compression
4. Water entering the combustion spaces can also cause this.

Sir, your Perkins generator needs intensive mechanical repair.

Thanks so much, it's a new generator that haven't worked up to 6months.I was told to change the oil filter, but I washed the follow come filter, it's working normal for now, even though I'm scared.

[quote author=AnaCheks post=55019291] Thanks so much, it's a new generator that haven't worked up to 6months.I was told to change the fuel filter, but I washed the follow come filter, it's working normal for now, even though I'm scared.

fastestshipper:
What do you think about Hyundai 150Rpm diesel generators? Do they have their parts in available in Lagos?

FG Wilson and Mikano 20Kva diesel generators now selling at 3.6 - 3.8 million naira while Hyundai 30kva is being sold for 2.4 million naira and Hyundai 40Kva selling for mere 2.8 Million naira.

Do you think it's safe and sensible to go for Hyundai instead of FG Wilson or Mikano?

Hyundai generators are manufactured in South Korea while Perkins generators such as Mikano, FG Wilson, Jubaili etc are manufactured in UK. Perkins generator parts are more affordable and can be easily get in Nigeria,especiallly place like Lagos. You can purchased their parts in Oregun Ikeja, Ilasa, Ladipo and many other smaller markets in Lagos but Hyundai generators parts are very scarce and expensive. Even as per maintenance sake, engineers self dey avoid them.

How do you maintain a Perkins engine?


Maintaining your Perkins engine is the key to its optimum performance. Slight changes in performance can easily go un-noticed, often a drop of 20% in performance can happen before the operator notices. Missing service intervals can lead to reduction in performance, let alone the worst case of a vital part failing.

Each engine supplied comes with a detailed list of checks for you to carry out at set intervals.The performance checks required will vary buy engine type and operating conditions, so it is wise to ensure the checks and frequency are right for your engine.

The regular checks that you need to carry out fall into daily and weekly categories, along with regular servicing and others at various specified intervals. They all have the same aim of ensuring that your engine runs as long as possible at the maximum efficiency. No two schedules are exactly the same, so you should always check the schedule for your particular engine.

Every Perkins engine has its own maintenance schedule.
It’s also worth noting that the checks either relate to the calendar time or the hours your engine has been running. Checks should take place far more often on an engine in almost constant use than for one used occasionally. So, for example, changing the cooling system engine coolant is recommended every two years – but it will need attention sooner if your engine runs for 3,000 hours, which is the equivalent of running 24/7 for just over four months.

Remember, the daily checks are just as important as the regular servicing

Daily checks include:

Cooling system coolant level
Driven equipment
The engine air cleaner service
Engine air pre-cleaner, cleaning it if necessary
Engine oil level
Fuel system primary filter/water separator
V-belts
Walk-around inspection
Every 50 service hours or weekly checks include:

Fuel tank water and sediment, draining if necessary

Troubleshooting Guide
Brief introduction
Troubleshooting can be difficult, and the possible problems are listed below. To handle the failures, please refer to the cause of the problem and its solution.
The following problems listed below are provided the following:

Known problems
Possible causes of the known problems
Repair to correct the known problems
Generally, in addition to the methods proposed in the form, the other repair works are also needed.
Remember that, in general, a problem is caused by more than one component. Cause of the problem may be related to the other components. All the problems that may occur and solutions are not included in the following table. Maintenance personnel must identify the problem and find the reason of the problem. Once the reason is found, the technician can make the necessary repairs.

Fault diagnosis
1). When the starting switch is in the (ON) position, the engine crankshaft does not rotate.
Possible causes:
1. Low battery output voltage
Check the battery status and, if necessary, charge or replace the battery.
2. Wire or switch is damaged.
If necessary, repair or replace the parts.
3. Solenoid coil of the starter motor is damaged.
Install the new solenoid coil.
4. Starting motor is damaged.
Repair or replace the starting motor.

2). The engine can be not started (when the starting switch is in (ON) position, the engine crankshaft rotates)
Possible causes:
1. There is no the oil in the fuel tank
Fill the oil with the fuel tank
2. Poor fuel quality
Drain the fuel in the fuel tank, install new fuel filter element. Fill the high quality fuel with the fuel tank
3. Too dirty fuel filter
Install the new fuel filter
4. Ruptured or dirty fuel pipeline
If necessary, clean or replace the fuel pipeline
5. Too low fuel pressure
Replace the fuel filter, and check if the fuel delivery pump is working normally. If necessary, install a new fuel delivery pump.
6. There is the air in the fuel system
Locate the leaks in the fuel system, and repair the leaks. Remove the air in the fuel system
7. The fixed drain valve is turned on (insufficient fuel pressure, unable to start the engine)
Replace the fixed drain valve
8. Slow starting speed
Check the battery status, if necessary, replace the battery
9. The oil supply solenoid valve can be not opened
If the solenoid valve is damaged, replace or check the circuit system
When starting (such as starting the system at 12V), the start voltage shall be not less than 10V, 24V, and the system voltage shall be not less than 18V. Charge the accumulator or replace the accumulator.

3). The engine is not running smoothly
Possible causes:

1. Low fuel pressure
Ensure that the fuel tank is provided with the enough fuel. Check whether the fuel system is leaked. Check if the fuel pipeline between the fuel tank and fuel delivery pump is seriously bent. Check whether there is the air in the fuel system. Check the fuel pressure. Under full load speed, check if the fuel delivery pump is normal. Check the pressure difference between the front and back of fuel filter element. If the fuel pressure is reduced, install a new fuel filter element.
2. There is the air in the fuel system
Locate the leaks in the fuel system, and repair the leaks. Remove the air in the fuel system
3. The fuel pipeline between the fuel injection pump and fuel injection valve is leaked or broken.
Install the new fuel pipeline.
4. The valve clearance is incorrect.
Adjust the valve clearance. Refer to the Test and Adjustment Section.

4). Engine stalling at low speed
Possible causes:

1. Low fuel pressure
Ensure that the fuel tank is provided with the enough fuel. Check whether the fuel system is leaked. Check if the fuel pipeline between the fuel tank and fuel delivery pump is seriously bent. Check whether there is the air in the fuel system. Check the fuel pressure. Under full load speed, check if the fuel delivery pump is normal. Check the pressure difference between the front and back of fuel filter element. If the fuel pressure is reduced, install a new fuel filter element.
2. Low engine idle speed
Adjust the speed governor
3. The valve clearance is incorrect.
Adjust the valve clearance.

5). The engine speed is changed abruptly
Possible causes:

1. There is the air in the fuel system
Locate the leaks in the fuel system, and repair the leaks. Remove the air in the fuel system.
2. Governor tie rod is unable to move freely
Clean all the connecting rods. Clean the interior of the housing of the speed governor. Replace all damaged parts with new parts.

6). Underpowered engine
Possible causes:

1. Poor fuel quality
Drain the fuel in the fuel tank, install new fuel filter element. Fill the high quality fuel with the fuel tank
2. Low fuel pressure
Ensure that the fuel tank is provided with the enough fuel. Check whether the fuel system is leaked. Check if the fuel pipeline between the fuel tank and fuel delivery pump is seriously bent. Check whether there is the air in the fuel system. Check the fuel pressure. Under full load speed, check if the fuel delivery pump is normal. Check the pressure difference between the front and back of fuel filter element. If the fuel pressure is reduced, install a new fuel filter element.
3. There is the air in the fuel system
Locate the leaks in the fuel system, and repair the leaks. Remove the air in the fuel system
4. The air intake system is leaked
Check the intake pipe pressure. Check the air resistance of the air filter
5. The fuel is set incorrectly
If necessary, adjust the fuel adjustment and setting
6. Fuel adjustment tie rod
Adjust the tie rod to the full stroke. Replace the damaged or failed parts
7. The valve clearance is incorrect.
Adjust the valve clearance.
8. The filter screen of the filter of the fuel delivery pump is blocked
Remove and clean the filter screen

DIESEL GENERATOR SMOKES (REASONS AND SOLUTION)

Is your generator embarrassing you by smoking up the neighbourhood? Reading this writeup could be the solution you need

Basically, smoke from a diesel engine indicates that something is not right , this will potentially shorten the engine life, or result in unnecessary costs.
A diesel engine in good condition should produce no visible smoke from the exhaust, under most operating conditions. A short puff of smoke when an engine is accelerated under load may be acceptable.

There are three basic types of smoke, as identifiable by their colour.

1. Black smoke is the most common smoke emitted from diesel engines. It indicates poor and incomplete combustion of the diesel fuel. There are many causes, including
Incorrect timing
Dirty or worn injectors
Injectors sticking open too long
Over-fuelling (yes this is possible)
Faulty turbocharger (ie not enough air to match the fuel)
Incorrect valve clearance
Incorrect air/fuel ratio
Low cylinder compression
Dirty air cleaner
Carboned up intake manifolds
Other engine tune factors
Poor quality fuel
Excessive carbon build up in combustion and exhaust spaces
Cool operating temperatures

2. Blue smoke is an indication of oil being burnt. The oil can enter the combustion chamber for several reasons.
Worn valve guides or seals
Wear in power assemblies (cylinders, piston rings, ring grooves)
Cylinder glaze
Piston ring sticking
Incorrect grade of oil (eg oil too thin, and migrating past the rings)
Fuel dilution in the oil (oil thinned out with diesel)

3.White smoke occurs when raw diesel comes through the exhaust completely intact and unburned. Some causes of this include
Faulty or damaged injectors
Incorrect injection timing (could be a worn timing gear or damaged crankshaft keyway).
Low cylinder compression (eg caused by leaking or broken valves, piston ring sticking, cylinder and/or ring wear, or cylinder glaze)
Water entering combustion spaces will also create white smoke

Op, please my 80 KvA Perkins generator is developing black smoke problem, how can you help me in effecting repair ?

are you freelance or you work with a generator company

jacqo:
Op, please my 80 KvA Perkins generator is developing black smoke problem, how can you help me in effecting repair ?

.

Just PM me on my signature, Send your contact address. I will come for inspection.

Op, we bought a 20kva gen from mikano in Lagos. It was a new one,after rarely using it for a year.it started giving issues and I decided to check the engine body. There is no inscription on the engine block or any part to show engine make,only a sticker on it. Pls is the gen a genuine one and how does one identify a original diesel generator.

id4sho:
Op, we bought a 20kva gen from mikano in Lagos. It was a new one,after rarely using it for a year.it started giving issues and I decided to check the engine body. There is no inscription on the engine block or any part to show engine make,only a sticker on it. Pls is the gen a genuine one and how does one identify a original diesel generator.

Check very well, u will see Perkins logo on d engine block. There is no fake Perkins engine, we have UK and China assembled one. Definitely, the U.K. Is more standard. We have inferior quality Perkins spare parts that are manufacture in China while the high quality Perkins parts are manufacture in UK. I strongly believe Mikano can't assembly less quality parts. More so, the durability of your generator depends on how you handle it. Pls,endeavor to read the safety and maintenance tip I have posted.

Thanks op, pls when will I know my generator is due for service ? I really found this thread interesting.

Please, what is or are the diference(s) between Mikano, Jubaili, Marapco,MANTRAC, FG Wilson generators. Oga, which one is better.

Today we shall discus Diesel Generators – Troubleshooting Cooling System Issues

Diesel Generators – Troubleshooting Cooling System Issues

Diesel Generators can have issues with the cooling systems.
Here we offer advice for on site checking of what to check before calling an engineer.
Operator’s Maintenance
The most important link in the maintenance chain is the engine operator. His daily and weekly checks of the cooling system and reports on any questionable conditions he observes will help prevent engine breakdown on the job and provide valuable information to engine repair people.
Each must be recorded and reported as and when they are found.


Diesel Generator Checks Before Start-up
1. Water level.
2. Cleanliness of coolant.
3. Radiator cap gasket.
4. Hose and connections for leaks or hose collapse.
5. Engine lubricating oil level.
Note
Oil level too low or too high will cause overheating and possible loss of the coolant.
6. Check for water in the oil and vice versa.
7. Inspect the fan for bent or damaged blades.
8. Check the belt for tension and condition.
9. Inspect the radiator for bent core fins or accumulation of debris. Check shutters for
damage or linkage wear.
10. Check for leaks at the cooler, water pump, or other accessories.

Diesel Generator Complaints and Causes
Loss of coolant due to external leakage.
1. Leaking pipe plugs, such as core plugs, which seal off coolant passages.
2. Loose clamps, faulty hose and piping.
3. Leaking radiator: Core hole plugs are sometimes loosened by corrosion or vibration.
These same conditions, or frozen coolant, can cause core seals to open up.
4. Leaking radiator, de-aeration top tank or surge tank.
5. Leaking gaskets due to improper tightening of cap screws, uneven gasket surfaces or
faulty gasket installation.
6. Leaking drain cocks.
7. Leaking water pump: Badly worn or deteriorated seals are the cause of leaks at the
pump. Premature failure of the pump seals often results from suspended abrasive
materials in the cooling system, or excessive heat from lack of coolant or cavitation.
8. Leaks at engine cylinder head gasket.
9. Leaks at upper cylinder liner counter bore.
10. Leaking engine or auxiliary oil cooler.
11. Leaking air intake after cooler (intake air heater in some cases).
12. Leaking water manifold and/or connections.

Tibeyjo:
Thanks op, pls when will I know my generator is due for service ? I really found this thread interesting.

I will answer this question with a table

Maintenance Service time

Items
Daily (D) Weekly( W ) Monthly ( M ) 6 Months (6M) Yearly (Y)
Inspection
Check coolant heater D
Check coolant level D
Check oil level D
Check fuel level D
Check charge-air piping W
Check/clean air cleaner W
Check battery charger. W
Drain fuel lter W
Drain water from fuel tank W
Check coolant concentration M
Check drive belt tension M
Drain exhaust condensate M
Check starting batteries M
Change oil and lter 6M
Change coolant lite 6M
Clean crankcase breather 6M
Change air cleaner element 6M
Check radiator hoses Y
Change fuel lters Y
Clean cooling system Y

But better still, do service your generator every 200 working hours

Anijo1:
Please, what is or are the diference(s) between Mikano, Jubaili, Marapco,MANTRAC, FG Wilson generators. Oga, which one is better.

Sir, Mikano,Jubaili,FG Wilson,Marapco are all Perkins engines manufactured in UK, they uses same spare parts, the only difference is the product name which is the brand. Those names are just the registered brand name,they don't manufacture generator but only assemble. While MANTRAC is caterpillar.

Though CAT product are ore durable and rugged and also more expensive.

In terms of which one is better, Oga, that depends on your purpose of purchasing them. If it's for home use, I strongly believe Perkins engines generator are ok because of cost effectiveness and maintenance but if it's for industrial purposes, you can go for CAT.

DoctorGenerator:
Its has become imperative that much informations about diesel generator and their simple maintenance techniques and safety tips are so scarce in this platform. So, I decided to be of an helping hand to those who are of need.

Erratic power supply or total darkness in Nigeria is not news any more. Most homes,businesses and manufacturing industries all relied on alternative source of power supply to run their machines. This machine cost lot of money, also, needs adequate attention and knowledge. So,feel free to post your technical questions, enquiery, maintenance tips, overhauling,electrical faults etc here.

morning sir

great job you are doing

I would like to know if you accept trainees for apprenticeship.

am a graduate of electrical and electronics engineering

and would love to acquire this great skill

please reply me with your contact details thanks

DoctorGenerator:
.

Just PM me on my signature, Send your contact address. I will come for inspection.

Engineer, thanks you for a good work well done job. Na you go dey do my generator from now

WE OFFER RELIABLE AND EFFECTIVE MAINTENANCE AND REPAIR OF DIESEL GENERATORS @ JT Engineering Services

Reliability is our watch word, why don't you off load your diesel generator maintenance and repair on our shoulders. You won't be disappointed because we have experienced professional to handle the task. 10kvA to the maximum ? Don't worry,we handle it.

Call 08152821022

Dr, please can you prescribe a good 5kva diesel generator?

AnaCheks:
Dr, please can you prescribe a good 5kva diesel generator?

Am not fronting for any brand of generator online sir. I only share my technical knowledge.
You can pm me to get my advice.

Thanks

very nice thread uve started here, pls am interested in buying a 15kva perkins or caterpiller gen set, if u have any for sale, pls let me know also what price can i get a fairly used one.

zamirikpo:
very nice thread uve started here, pls am interested in buying a 15kva perkins or caterpiller gen set, if u have any for sale, pls let me know also what price can i get a fairly used one.

Pls kindly give me a call on 08152821022, we can talk about it. Thanks