Generators are shaft-driven machines that produce electric power. Broadly speaking, they range in size and capacity from the tiny devices used as sensors to the extremely large machines used at commercial power plants. The term “alternator” is also used and means essentially the same thing. The term “generator set” or “genset” is sometimes used to describe a generator along with a diesel or gasoline engine or other power source.

The stated or guaranteed net electric output which is obtainable continuously from a Generating Set when it is functioning at rated conditions. If the set is equipped with additional power producing devices, then the stated or guaranteed net electric power must take into consideration that the auxiliaries are delivering their respective stated or guaranteed net output simultaneously, unless otherwise agreed to.

That source of supply of electrical energy utilised by the user which normally available continuously day and night, usually supplied by an electric utility company but sometimes by owner generation.

An independent reserve source of electrical energy which upon failure or outage of the normal source provides electric power of acceptable quality and quantity so that the user’s facilities may continue in satisfactory operation

In selecting an Alternating Current (A.C.) generating set consider the following points:

1. Total electrical load connected - including any motors i.e. Bore hole pump etc.
2. Voltage, frequency and phase
3. Special requirements
4. Does the Generator need to start automatically?
5. Acceptable sound emissions
6. Altitude and Running time


CONNECTED LOAD or ASSESSED LOAD

Having assessed the total connected load, consider next the portion of the load that is likely to be switched on at any time. A Generator set with an output a little in excess of the figure should be selected to allow for contingencies. Always allow for future expansion.


VOLTAGE, FREQUENCY AND PHASE

A.C. current is usually supplied by Public Electricity undertakings in sub-Saharan Africa at 230volts and a frequency of 50 cycles (Hertz). The normal supply to the average house is single phase being a two wire systems. The three phase four wire system is usually taken to factories to give higher voltage (The voltage between phases, known as the line voltage has a direct relationship to the phase voltage. 1.73 to 1, i.e. - 230 volt phase voltage, 400 volt line voltage). It is advantageous to use a three - phase supply for electric motor loads both on consideration of price and starting characteristics. Single phase sets with outputs up to 12kW or 15kVA are normally sufficient for domestic installations.


Manual change over:

This is a manual switch normally with a pilot light wired so that when the mains is on the light shows. It would have a Mains/Neutral/Generator switch to ensure that it is either mains on or generator on but never both.


Automatic Standby to Mains:

Sets can normally be supplied which start automatically and take up the load when the mains fail. On restoration of the mains supply the load is automatically transferred to mains and the generator set shuts down. There will always be a delay between mains failure and the generator starting up and supplying full load so if sensitive equipment is being used or computer systems an Uninterrupted Power Supply (UPS) should be installed to ensure no loss of Data. Time delay on switch over can be between 3 seconds and 30 seconds dependant on the generator system installed.


Altitude and Running time

When sizing your generator it is imperative that you take your altitude into account. In general you lose 1% efficiency for every 100m above sea level. If you are in Johannesburg, about 1600m above sea level, you would lose 16% output. A 100kVA unit will therefore produce about 84kVA.

In addition to upsizing the generator based on the altitude, it is important to consider how long the generator will run for.

A generator running as prime power (24 Hours a day) should not run at more than 80% load. Simply put, if you are driving a car, you would not have your foot flat on the accelerator all the time.

A generator running as a standby unit, the unit can run at 110% load for 1 hour out of every 12 hours. Using the Johannesburg example again, a 100kVA generator, de-rated for altitude (1600m = 16%) would be a 84kVA. If used as a standby unit you would be able to run the unit at 110% load for 1 hour out of every 12. Giving you 92.4kVA. This additional power is allowed to start up things such as electric motors and fridges which use more power to start than when they are running.

Using the Gencor ATS (Automatic Transfer Switch) Panel, you can connect the Diesel Generator to the Main Power Supply. The ATS will be ON / OFF automatically when the power comes back / fails from the main source without the risk of feedback.

Our highly skilled maintenance team is always ready and equipped. We have the required tools and vehicles to reach the fault site on time and do the repairing or preventive maintenance.

Electrical appliances which have metal casings can sometimes become "live" or electified due to the cable touching the housing or something conducting the electricity to the outer case. This could cause a nasty shock if it isn't earthed.

This included Oven's / Stove's, fridges, microwaves, kettles, refrigerators, washing machines and dish washers. Basically anything with a metal outter housing. The earth wire prevents this from happening by taking the current through the earth cable to the point where the earth has been grounded. The earth cable is low resistance and hence when the current flows through it, it breaks the fuse and disconnects the appliance. It can also trip the circuit breaker at the main distribution board.
 

SAE Standard J620 defines Flywheel configuration for industry standardization, interchangeability, and compatibility.

SAE Standard J617 specifies the major dimensions and tolerances for Engine Flywheel Housings and the Mating Transmission Housing Flanges. It also locates the crankshaft flange face or the transmission pilot bore (or pilot bearing bore) stop face in relation to housing SAE flange face. This document is not intended to cover the design of the flywheel housing face mating with the engine crankcase rear face of the design of housing walls and ribs. Housing strength analysis and the selection of housing materials are also excluded. This standard applies to any internal combustion engine which can utilize SAE No. 6 through SAE No. 00 size flywheel housing for mounting a transmission.

The following graphical picture shows the typical configuration and their respective SAE denomination. To determine the SAE adaption in your specific application, simply match dimensions XD, XB, XE, XF and XG to arrive at a combination of SAE adaptions for the engine housing and engine flywheel. For example, SAE No. 3 Housing with SAE No. 11-1/2 Flywheel.

Class-A Maintenance (Daily Care)

• Check generator working condition on daily basis.
• Check the generator lube oil level, radiator water level.
• Generators daily inspection for damage, leakage, whether the belt is loose or worn.
• Check the air filter, clean the air filter core and replace if necessary.
• Release of the fuel tank and fuel filter in the water or sediment.
• Check the smooth oil flow through filters.
• Check the starter battery and battery fluid, if necessary, adding replenisher.
• Start the generator and check for abnormal noise.
• Clean the tank with an air gun, coolers and cooling network dust.

Class-B Maintenance (100-250 Operation Hours)

• Class-A repeated daily inspection.
• Every 100-250 hours, to replace the diesel filter;All diesel filter can not be cleaned. Only can be replaced. 100-250 hours is a flexible time must be based on actual Clean Diesel and replaced.
• Every 200-250 hours, to replace the generator oil and oil filter;Oil must meet API CF or above U.S.
• Replace the air filter (unit running 300-400 hours);Room environment should pay attention to while the time decided to replace the air filter, this filter can be cleaned with an air gun.
• Replace the water through filter and add DCA concentration.
• Cleaning crankcase breather valve strainer.

Class-C Maintenance (2000-3000 Operation Hours)

• Repeat Class A & B level maintenance.
• Remove the valve cover, cleaning oil, sludge.
• Fastening screws ministries (including running part, the fixed part).
• With the engine crankcase Jie Ba cleaning, sludge, iron and sediment.
• Check the wear on the turbocharger and clean coke, if necessary, adjust.
• Check and adjust valve clearance.
• Check the PT pump, fuel injector work, adjusting injector stroke, when necessary adjustments.
• Check and adjust fan belt, water pump belt tension, if necessary, adjust or replace: cleaning water tank cooling network and check the thermostat performance. Minor repairs (i.e, D-level maintenance) (3000-4000 hours) check valve, valve seat and other wear and tear, if necessary, repair or replacement.
• Check the PT pump, fuel injector working conditions, if necessary, repair, adjustment.
• Check and adjust linkage and the fastening screws of torque;Check and adjust valve clearance.
• Adjust injector stroke;Check and adjust fan belt tension charger.
• Cleaning the intake manifold of coke;Cleaning intercooler core.
• Clean the whole engine oil lubrication system.
• Cleaning rocker chamber, oil pan sludge and metal filings.

Reparing (6000-8000 Operation Hours)

• Containing a small repair projects.
• Resolution engine (except crankshaft outside).
• Check the cylinder, piston, piston rings, intake and exhaust valves, etc. crank, valve, lubrication system, cooling system, wearing parts and replace if necessary.
• Check the fuel supply system, adjustable oil pump nozzle.
• Generator power ball repair detection, clean oil deposits, lubricated electric ball bearings.

Overhaul (9000-15000 Operation Hours)

• Included in the repair project.
• All engine disintegration.
• Replacement of the cylinder block, pistons, piston rings, size bearings, crankshaft thrust pad, intake and exhaust valves, complete engine overhaul kits.
• Adjust the oil pump, fuel injector, replace pump core, fuel injection head.
• Replace turbocharger overhaul kits, water pump repair kits.
• Calibration rod, crankshaft, and other parts of the body, if necessary, repaired or replaced.

Generating Sets are rated in terms of the amount of power they can produce. This is measured in Watts (W) or Kilowatts (kW) and Volt Amperes (VA) or Kilovolt Amperes (kVA). A Kilowatt is equal to 1,000 Watts

kW = kVA x Power Factor
e.g.

If kVA = 25 and Power Factor = 0.8 then kW=?
Answer:
kW = kVA x Power Factor
kW = 25 x 0.8
kW = 20

Here’s some basic advice on Generating Set safety. Read the instructions for your Generating Set or check with a dealer or licensed electrician for authoritative safety rules.

1. Follow the safety instructions that come with the Generating Set.
2. Keep the Generating Set outside so you don’t breathe carbon monoxide. Protected locations, such as a garage with the garage door open, are helpful if the weather is bad.
3. Don’t refuel a hot engine. If you refuel at night, use a source of light that won’t ignite the gas.
4. Don’t overload extension cords.
5. Use a transfer switch.
6. Store fuel outside, in a safe container

Because of the way diesel engines are built they will last many times longer than a gasoline powered engine.