Load Bank Testing for Generators
A Load Bank test will provide timely identification of any problems with your generator and the remedial actions necessary.
Do you rely on your Generator as part of a Critical Power System?
If you do, then a periodic load bank test is essential to ensure that it will run smoothly and efficiently when you need it. Why? Because just starting up your generator every now and again is not enough.
Imagine just starting up a car and not driving it. Would you be confident it would perform for 500 miles? No? So why assume a Generator will from a simple auto start test? Full resistive Load Bank testing will push the unit to its limits so you can be sure it will work efficiently when you need it.
What does a Load Bank Test?Generator
* The engine and its ability to provide the required power over time by using an artificial load
* The alternator’s ability to provide the required voltage stability
* Frequency stability
* Efficient Control systems under varying conditions of load
* The performance of whole system
* Oil and fuel pressure to make sure the engine is well lubricated and gets enough fuel to produce the power you need it to provide
What else will a Load Bank test provide?
* Remove deposits from pistons, engine casings & exhausts
* Identify potential weaknesses
* Record results and remedial work to be done
Full testing of the generator under load will ensure that all the components within the system will work and perform together as intended when called upon to support a critical load.
To discuss Load Bank Testing Services, request service information sheets or pricing, please call our service team on (270) 519-3093 (270) 642-2177
Load Bank Testing – This is usually done at the same time as the oil change, if the generator is not tested at least twice per month with the manufacturers’ recommended minimum load. It is recommended to load test the generator once per year. The following are the recommended test lengths.
Generator output Length of 100% Load Bank Test
100 kW and less. 1 hour
100 to 200 kW 2 hours
200 kW and larger 4 hours
LOAD BANK TESTING
"Be Ready for Your Next Building Inspection"
Load Bank Testing will prolong the life of your power equipment and reduce the risk of unnecessary engine or generator failure.
Load Bank Testing allows a standby or prime power system to be tested and exercised under load to verify its overall reliability to perform in an emergency power situation.
Load Bank tests the engine's ability to produce kW and the generator's ability to produce kVA. It confirms the generator's ability to come up to full load and stay there without overheating and possibly shutting down. Testing also includes evaluation of other critical system spec's, such as oil and fuel pressure, to make sure the engine is well lubricated and gets enough fuel to produce the power your system requires.
Testing results are furnished with any recommendation for repair, and are added to your Service History.
Load Bank Testing
Don't wait until the power goes out to learn that your generator isn't working properly. Even if you test run your generator regularly, there can still be problems that won't appear until your generator is run with a load. Load Bank Testing allows the generator to be tested at its rated capacity. While it is being tested, our technician will be monitoring the generator for proper output, oil and fuel pressure, and proper cooling. Generators that are run with little or no load can experience "Wet Stacking". Wet Stacking is caused when carbon builds up in the cylinders. It will cause the engine to bog down and smoke. Load Bank Testing burns off this carbon and allows your generator to run at maximum performance rating. Call today to schedule a Load Bank Test!
Testing and Load Banking
Routine testing of the generator builds confidence in the equipment's ability to perform and is vital in ensuring that the generator remains in full working order. In circumstances where testing the generator on building load is not appropriate or not possible, we can provide temporary load banks to simulate full generator output and subsequently provide a written report with any recommendations that may be necessary.
Our portable resistive load banks are available to meet the requirement for testing generating sets, uninterruptible power supplies (UPS) and battery systems at the site of installation with a minimum of disruption. No change over of electrical supplies is required and the equipment under test is electrically isolated from the building, which it normally supports.
The load bank test is able to provide a full rated load test of the generator and tests the equipment under controlled conditions. It thus provides the user with the peace of mind that the equipment has been tested to its maximum capability as installed, and may be considered suitable for continued operation under any emergency conditions. It may further be used to test equipment by simulating the application and removal of large and small transient loads and monitoring the response of the generator under such loads.
We can supply the load bank, cables and with the ability to assess the performance of the equipment throughout the test. Test periods normally last for between one and four hours.
LOAD BANK TESTING
of Engine/Generator Sets
Engine/generator sets, or gensets, represent a sizeable capital investment, and they are seldom installed as amenities of convenience. Their failure to perform properly when pressed into service is almost always accompanied by actual or potentially dangerous conditions and/or significant financial loss. Periodic maintenance and testing are essential to ensuing that the unit unfailingly performs its duties when called upon to do so.
Plant engineers with genset responsibilities are well aware of the need for preventive/predictive maintenance and periodic operational test-running of their units. If the genset is an emergency unit required by building safety code (as opposed to a standby unit installed at the owner's discretion), required minimum test conditions and frequency of testing are prescribed by applicable codes.
Periodic load bank testing is an important element of a comprehensive genset predictive maintenance program, but it is seldom specifically required by code. An example of one of the rare exceptions is found in NCPA 110 Emergency and Standby Power Systems, which requires load bank testing for mandated emergency units serving critical areas in hospitals.
A load bank is a stationary or mobile piece of equipment that provides operator-adjustable electrical resistance or resistance and reactance to simulate the actual electrical load the genset is intended to power. Load bank testing simulates the electrical demands of one or more items of electrical equipment, specific processes within the plant, or an entire facility. The test monitors the engine and generator to ensure that each is doing its job.
Circuit resistance and reactance combine vectorially to form total circuit impedance. Current flow through the load resistive component yields kW, which, in turn, determines the horsepower load that will be imposed on the engine. Current flow through the total circuit impedance yields kVA, which translates into the heating that will be imposed on the generator.
The following recommendations for an overall engine/generator PM program are general guidelines only, to be modified in accordance with specific circumstances.
The system should be started and operated for 30 to 40 min, either with or without electrical load imposed on the unit. A visual check should be made for fuel and oil leaks, and any abnormal noises investigated. Engine fluids, gauges, and instruments should be checked.
The unit should be run for 30 to 40 min under actual load, and all weekly-check items observed. (Scheduled load bank testing increases in importance in cases where it is unfeasible to test gensets under load on a regular basis.) Engine cranking battery electrolyte levels should be checks, and battery specific gravity hydrometer readings should be taken.
Every six months or 250 engine-operating hr, a thorough inspection should be made of the entire cooling, fuel, starting, lubricating oil, and air intake/exhaust systems. Oil should especially undergo spectrophotometry and infrared analysis to confirm its integrity. System safety control systems and unit control panels should also be checked. The generator and exciter stator and rotor windings should be checked with a megohmeter to detect any insulation degradation.
Every year or 250 engine-operating hr, engine oil, and oil, air, and furl filters should be changed. An engine coolant condition analysis should also be performed. The engine/generator should undergo a resistance/reactance load bank test over its full load range for a minimum of 2 hr.
Every 2 yr, the engine coolant system should be thoroughly flushed and refilled. Upper and lower radiator hoses, belts, and block heater hoses should be replaced.
Bank Test Verification of Voltage Regulator Operation
Testing with a resistance/inductance load bank permits block loads to be introduced having the same impedance characteristics as actual in-service loads.
Problems Eliminated by Periodic Load Bank Testing
It is advisable to perform load bank testing on an annual basis, because it can eliminate problems brought on by neglect and underutilization. Weekly test operation under no-load or light-load conditions does not permit engine fluids to attain proper operating temperature. Cooling system controls will not be properly exercised, preventing coolant from circulating through radiators, and inviting failures stemming from inactivity. Engine safety shutdown systems are not subjected to actual operating conditions, and are therefore not fully tested.
Diesel-driven units are subject to a particular malady known as "wet stacking" or "slobbering" that stems from operation under no-load or light-load conditions. Such operation causes fuel deposits to collect on the combustion chamber, injector nozzles, piston rings, turbocharger, and exhaust system. The result is diminished engine output capacity. Regular load bank testing burns off accumulated deposits and preserves engine output capability.