How To Size Generators

1. How To Size Generators

2. What do Generators have to do with Quantum Controls? Sizing of diesel generators is critical to avoid low-load or a shortage of power and is complicated by modern electronics, specifically non-linear loads.

3. What is a generator? • A diesel generator is the combination of a diesel powered engine with an electric generator (often an alternator) to generate electrical energy • Why would we use diesel over grid mains? • No mains available from grid • Temporary installation / application • Not enough power from existing mains grid supply • Loss of grid supply

4. Generators & Variable Speed Drives Have you the right size? Generating sets are selected based on the electrical load they are intended to supply, the electrical loads total characteristics (kWe, kVA, var's and Harmonic Content including starting currents (normally from motors) and non-linear loads. Sized too small….. Generators stall’s, trips on overload and Ultimately will not power the application Sized too big.....Look what the experts say!

5. Generators & Variable Speed Drives • Does size matter…Yes!! • Diesel engines should be run at least 60% to 75% of their maximum rated load. Short periods of low load running are permissible providing the set is brought up to full load, or close to full load on a regular basis. • Why? Internal glazing and carbon build up is due to prolonged periods of running at low speeds or low load • Such conditions may occur if the engine powering the set is over-powered for the load applied to it, causing the diesel unit to be under-loaded, or as is very often the case, when sets are oversized to accommodate a motor starting peak current

6. So back to the motors… • How does over sizing occur and how do we size a generator for motor starting? Normally: • DOL Starting = up to 7 x Peak full load current • Star delta = up to 6 x Peak full load current • Auto TX = up to 5 x Peak full load current • Soft start = up to 4 x Peak full load current So with a DOL motor starter rated at 110KW a generator set rated to approximately 850Kva would be required Motor absorbed running = 150Kva approximately Result = Generator is oversized by 80%

7. VSD Control & Implications • Motor control using variable speed drives will typically give you 100% torque from zero speed and as the unit controls frequency rather than voltage then most motor applications such as pump, fan etc. can be started within the full load current of the motor. • Generator sizing can be vastly reduced to match the maximum required power the drive requires for the load • Low harmonic option drives to further reduce sizing of generator sets from Quantum Controls Ltd

8. VSD V’s DOL • So to compare to the DOL example: • 110KW VSD motor starter, a 200Kva generator could be used • Motor absorbed running = 150Kva approximately Generator oversized by 25% (should be run at least 60% to 75% ) Sizing is acceptable: Generator size reduction V’s DOL = 75% reduction

9. Would you power this? Low power requirement car With this amount of power?

10. Only if you want to end up in trouble!!

11. So why would we power this? 22KW Fan Motor with DOL Control With this oversized generator set..

12. We worry about mpg, so why not fuel per kWh? • A generator typically will use between 0.28 to 0.4 litres of fuel to per KWH • Fact – A larger generator set will cost you more to run, bigger the engine the more fuel it consumes! • More space to store • More CO2 Used • More generator rental costs

13. Here Is a typical Saving Example • 110KW DOL Motor with an 850Kva set example: • Per hour operation = 110KW x 0.4 litres of fuel = 44 litres of fuel per hour • 44 litres x 70p per litre (approx.) = £30.80p per hour to run • CO2 = 61kg per hour • Rental cost for set of approximately £950 per week

14. Here Is a typical Saving Example • 110KW VSD Motor with an 200Kva set example: • Per hour operation = 77KW x 0.28 litres of fuel = 21.56 litres of fuel per hour • 21.56 litres x 70p per litre (approx.) = £15.09p per hour to run • CO2 = 43kg per hour • Rental cost for set of approximately £450 per week

15. Here Is a typical saving example • So the summary of savings: VSD V’s DOL • Per hour operation = 33KW of power saved • Litres x 70p per litre (approx.) = £15.71p saved per hour to run • CO2 = 18kg per hour saved • Rental cost for set of approximately £500 per week

16. Here Is a typical guide from QC

17. What else can we offer? The latest new technology from The UK’s largest VSD, motor and Power options hire fleet Fractional to 1500KW, 240V to 11Kv as standard Not just motors we control but power Supplies too.. How?

18. Power Supplies: • As an example; Client requires: 200Kva at 3,300V variable frequency 0-70Hz supply is required on a test rig from a 415V generator supply • How do we do it? We can offer: 415V 250Kva generator → 250Kva 415V VSD → 250Kva sine filter → 415/3300V 250 KVA TX → 250Kva @ 3300V variable frequency supply with a clean wave form and voltage stabilisation capabilities Result = a medium voltage variable frequency supply at low voltage pricing!

19. Our Newest panels..IP65 VSD 400KW

20. What can we Hire? • Variable speed drives IP65 rated • Soft start panels IP65 rated • AC motors up to 500KW • Motor control starters • Diesel Generators • Mains cable • Flow meters • Switchgear • UPS • Turn key solutions

21. So what is your best practice? Lower cost diesel power: Lower CO2 Lower running costs Lower rental rates Smaller generator sets Higher voltage at lower costs Wider supply range A viable solution A one stop solution Use Quantum Controls VSD

22. Confused? Ask us… Quantum Controls have hired VSD units over 10 years with an unrivalled fleet of units We have won 3 national energy reduction awards in last two years, all evolving around hire trials How can you hire 24/7/365 Call 0330 900 0247

23. Quantum Controls Ltd