Basic knowledge of diesel generator

1. What are the six systems included in the basic equipment of a diesel generator set?

A:

(1) Oil lubrication system;

(2) Fuel system;

(3) Control and protection system;

(4) Cooling and cooling system;

(5) Exhaust system;

(6) starting system;

2. Why do you advise customers to use oil recommended by professional companies in sales work?

A:

Oil is the blood of the engine. Once customers use unqualified oil, it will lead to serious accidents such as bearing bush bite, gear tooth beating, crankshaft deformation and fracture, until the whole machine is scrapped.Specific engine oil selection and use

3. What new machine needs to change the oil and oil filter after a period of use?

A:

New machine in the run-in period will inevitably have impurities into the oil pan, so that the oil and oil filter physical or chemical quality change.In the process of after-sales service and package for the units sold by Wuhan Jieli, we will have professional staff to carry out related maintenance for you.

4. Why should the smoke exhaust pipe incline 5-10 degrees downward when customers install the unit?

A:

Mainly to prevent rain water into the exhaust pipe, leading to major events.

5, general diesel engines are equipped with manual oil pump and exhaust bolts, what is their role?

A:

Used to remove air from fuel line before starting.

6. How to divide the automation level of diesel generator sets?

A:

Manual, self-start, self-start with automatic mains conversion cabinet, long distance three remote (remote control, telemetry, remote monitoring).

7. Why is the outgoing voltage standard of the generator 400V instead of 380V?

A:

Because the outgoing line has voltage drop loss.

8, why the use of diesel generator set must be smooth air?

A:

The output of the diesel engine is directly affected by the quantity and quality of the air inhaled, and the generator must have sufficient air to give cooling.So the use of the site must be smooth air.

9, why in the installation of oil filter, diesel filter, oil and water separator should not use tools to screw the above three devices too tight, and only need to use hand to avoid oil leakage can be?

A:

Because if it is too tight, the sealing ring will expand thermal under the action of oil bubble and heating of the body, resulting in great stress.Causes damage to the filter shell or separator shell itself.More seriously, the screw of the machine can not be repaired.

10. How to identify fake and shoddy domestic diesel engines?

A:

First check whether there is a factory certificate and product certificate, they are the factory of the diesel engine “proof of identity”, is a must.

Check the three numbers on the certificate again

(1) Name plate number;

(2) Body number (physically, it is generally on the plane machined by the flywheel end, and the font is convex);

(3) Nameplate number of oil pump.These three numbers must be checked with the actual number on the diesel engine.If any doubt is found, the three numbers can be reported to the manufacturer for verification.

11. After the operation electrician takes over the diesel generator set, what three points should be verified first?

A:

(1) Verify the real useful power of the unit.Then determine the economic power, and reserve power.Verification unit of real useful method is: the power of diesel engine 12 hours reach by 0.9 rated power (kw), a data generator power rating if less than or equal to the data, with real useful power generator power rating as the unit, if the generator power rating is more than the data, you must use the data as a real useful power of the unit.

(2) Verify what kind of self-protection function the unit has.

(3) Verify whether the power wiring of the unit is qualified, whether the protective grounding is reliable, and whether the three-phase load is basically balanced.

12. There is an elevator starter motor of 22KW. How large a generator set should be equipped?

A:

22*7=154KW (elevator is a direct load starting model, the instant starting current is generally 7 times of the rated current,

To ensure that the elevator for uniform motion).(i.e. at least 154KW generator set)

13. How to calculate the optimal power (economic power) of the generator set?

A:

P Best =3/4*P rating (i.e., 0.75 times rated power).

14. How much does the state stipulate that the engine power of the general generator set should be larger than the power of the generator?

A:

10 ℅.

15, some generator set engine power is expressed by horsepower, horsepower and international unit kilowatts between how to convert?

A:

1 horsepower =0.735 kW, 1 kW =1.36 horsepower.

How to calculate the current of three-phase generator?

A:

I = P / 3 Ucos phi) () the current = power (watts) / 3 * 400 () (v) * 0.8).The simple calculation formula is: I (A) = the rated power of the unit (KW) * 1.8

17. The relationship between apparent power, active power, rated power, maximum power and economic power?

A:

(1) The unit of apparent power is KVA, which is used to express the capacity of transformer and UPS in China.

(2) the active power is 0.8 times of the apparent power, the unit is kW, our country is used for power generation equipment and electrical equipment.

(3) The rated power of a diesel generator set refers to the power that can be operated continuously for 12 hours.

(4) The maximum power is 1.1 times of the rated power, but it can only be used for 1 hour within 12 hours.

(5) the economic power is 0.75 times of the rated power, which is the output power of the diesel generator set that can be operated for a long time without time limitation.At this power operation, the fuel is the most economical, the lowest failure rate.

18. Why not allow the diesel generator set to operate for a long time at less than 50% of the rated power?

A:

Increased oil consumption, diesel engine easy to carbon, increase the failure rate, shorten the overhaul cycle.

19. The actual output power of the generator during operation shall be subject to the power meter or the ammeter?

A:

The ammeter shall prevail, and the power meter is for reference only.

The frequency and voltage of a generator set are unstable. The problem lies in the engine or the generator.

A:

It’s in the engine.

The frequency of a generator set is stable, and the voltage is not stable. The problem lies in the engine or the generator?

A:

It’s in the generator.

What is the generator loss of magnetism, how should be dealt with?

A:

The power generation is not used for a long time, leading to the loss of residual magnetism contained in the iron core before delivery, and the excitation coil can not establish the due magnetic field. At this time, the engine runs normally but can not generate electricity. This kind of phenomenon is a new machine.Or long-term use of the unit is more.

Treatment method:

(1) If there is an excitation button, press the excitation button.

(2) If there is no excitation button, magnetize it with a battery;

(3) with a bulb load, overspeed operation for a few seconds.

After a period of time, the generator set found that everything else is normal but the power is down. What is the main reason?

A:

A, the air filter is too dirty, inhaled air is not enough, then the air filter must be cleaned or replaced.

B. The fuel filter device is too dirty and the amount of fuel injection is not enough, so it must be replaced or cleaned.

C. Ignition time is not correct and must be adjusted.

There is a generator set with load after its voltage and frequency are stable, but the current is not stable, where is the problem?

A:

The problem is that the customer’s load is erratic and the generator quality is absolutely fine.

The frequency of a generator set is not stable, where is the main problem?

A:

The main problem is that the speed of the generator is not stable.

What are the most important points that must be paid attention to in the use of diesel generator sets?

A:

(1) The water in the water tank must be sufficient and keep working within the allowable temperature range.

(2) the lubricating oil must be in place, but not excessive, and keep working within the allowable pressure range.

(3) The frequency is kept at about 50Hz and the voltage is kept at about 400V.

(4) The three-phase current is within the rated range.

27. What are the parts and components that need to be replaced or cleaned regularly in a diesel generator set?

A: diesel filter, oil filter, air filter.(Individual units also have water filters)

28. What are the main advantages of brushless generators?

A 1) from the maintenance of the brush;

(2) anti-radio interference;

(3) reduce the loss of magnetic fault.

29. What is the insulation grade of domestic generators?

Answer: domestic machine B grade;Marathon brand, Lilythamar brand and Stanford brand are H class.