Standby Generator Checklist - useful for data centre standard operating procedures

 

This checklist is based on a checklist from the University of Manitoba. (the link to the original document is not available).

• Documentation
  
  • Site drawings.
    
    • Engine: make and model, with specifications.
    • Generator: make and model, with specifications.
    • Battery: make, type and capacity.
    • Battery charger: make, type and model.
    • Automatic transfer switch: make, model and type.
    • Engine/generator control panel: make and type of meters and controls.
    • Governor: type and model.
    • Radiator: type, model and capacities.
  • Dimensioned drawings showing complete generating set mounted on steel base, including interconnect points for fuel system, exhaust system, cooling system, and load leads.
  • Prototype testing data.
  • Performance characteristics based on standard conditions of 100 KPA and 25°C.
  • Wiring diagrams showing interconnection points of all electrical components.
  • Operating instructions:
    
    • Automatic starting and transfer to load and back to normal power, including time in seconds from start of cranking until unit reaches rated voltage and frequency.
    • Manual starting.
    • Automatic shut down.
  • Prototype test certificate.
  • Factory test results.
• Operation and maintenance data
  
  • Operation and parts manual
    
    • Operation instructions - with description and illustration of all switchgear controls and indicators and engine and generator controls.
    • Parts book - that illustrate and list all assemblies, sub-assemblies and components, except standard fastening hardware (nuts, bolts, washers, etc..).
    • Preventative maintenance instructions - on the complete system that covers daily, weekly, monthly, bi-annual and annual maintenance requirements and includes a complete lubrication chart.
    • Troubleshooting chart - covering the complete generator set showing description of trouble, probable cause, and suggested remedy.
    • Recommended spare parts list - showing all consumables anticipated shall be required during routine maintenance and test.
    • Wiring diagrams and schematics - showing function of all electrical components.

• Maintenance manuals
  
  • Maintenance materials
    
    • Fuel filter replacement elements.
    • Lube oil filter replacement elements.
    • Air cleaner filter elements.
    • Set of fuses for control panel.
    • Battery hydrometer.
• Prototype testing
  
  • The power system consisting of prime mover, generator and all necessary controls shall be tested as complete systems on representative engineering prototype models. The tests, being potentially damaging to the equipment tested, shall not be performed on equipment sold, but on separate prototype models. A certificate certifying that this prototype testing has been performed, should be submitted. These tests shall have included, but not have been limited to:
    
    • Maximum power level (maximum kW).
    • Maximum motor starting capacity (maximum kVA).
    • Structural soundness.
    • Torsiograph analysis. A torsional analysis shall be calculated using data from actual tests by the engine-generator set manufacturer to verify freedom from torsional stresses with ±10% of rated speed. Results shall be made available to Consultant upon request. Actual torsional fatigue test shall be performed on the complete prototype generator-set. Calculations based on engine and generator data separately are not acceptable.
    • Engine-alternator cooling air flow.
    • Transient response and steady-state governing.
    • Alternator temperature rise by embedded thermocouples and by resistance method.
    • Harmonic analysis and voltage wave form deviation.
    • Three-phase short-circuit test for mechanical and electrical strength. With system operating at rated volts, amps, power factor, and speed, the generator terminals shall be short circuited ten times on all three phases for a duration of thirty seconds. Generator set shall build up and perform normally without manual interventions of any kind such as re-setting of circuit breakers or other tripping devices when the short circuit is removed.
    • Failure mode test for voltage regulator. With generator set operating at no load, rated speed and voltage, the AC sensing circuit to the regulator shall be disconnected for a period of at least one hour. The generator set shall be fully operative after the test, and without evidence of any kind of damage.
    • Endurance testing at rated load and speed is required without significant damage or failures of electrical or mechanical components.
• Factory testing
  
  • Before shipment of equipment, factory test generator set including engine, alternator, control panels, transfer equipment and accessories for performance and proper functioning of control and interfacing circuits.
  • Test procedures shall include:
    
    • Load test at rated load and power factor for a continuous 2 hour time period to observe engine blow by, slobber, combustion gas leaks, inlet air leaks, excessive vibration and unusual noise.
    • Single step load pickup.
    • Transient response and steady state governing.
    • Alternator temperature rise by resistance method.
    • Functional compatibility between generator set controls and transfer switch controls (start, transfer, re transfer, stop, with all time delays).
    • Fuel consumption.
• Field testing
  
  • Prior to the official field test, the following related items shall be completed and operational:
    
    • The ventilation system and related damper controls for the generator room.
    • The fuel tank, float sensors and related pumps.
    • The insulation on the exhaust system.
    • The remote radiator, related piping and electric fan with controls.
    • The door to the generator room shall be in place, complete with hardware.
    • Sealing of the generator room from the other rooms in the building.
    • The complete standby power system shall be initially started and checked out for operational compliance by factory-trained representatives of the manufacturer of the generator set. The initial start-up shall be performed at least two days in advance of the Field Test to allow the factory representative time to correct any part of the system which may not be functioning properly.
  • Upon completion of the above items the standby power system shall be ready for a Field test which shall be performed by the generator set supplier and witnessed customer designated consultant.
  • Advance notification of the Field test.
  • Test procedure:
    
    • Prepare blank forms and check sheet with spaces to record data. At top of first sheet record:
      
      • Date.
      • Generator set serial number.
      • Engine make, model, serial number.
      • Alternator make, model, serial number.
      • Voltage regulator make and model.
      • Rating of generator set kW, kVA, V, A, RPM, Hz.
    • Mark check sheet and record data on forms in duplicate as test proceeds.
    • Submit test results with the Maintenance Manuals.
    • With a portable resistive load bank at 100% rated load of generator, operate set for 6 hours, taking readings at 30 minute intervals, and 110% rated load for 1 hour and record following:
      time of reading
      
      • Running time.
      • Ambient temperature in °C.
      • Lube oil pressure in kPa.
      • Lube oil temperature in °C.
      • Engine coolant temperature in °C.
      • Exhaust stack temperature in °C.
      • Alternator voltage, Phase A, B, C, AN, BN, CN.
      • Alternator current, Phase A, B and C.
      • Power in kW.
      • Frequency in Hz.
      • Power factor.
      • Battery charger current in A.
      • Battery voltage.
      • Alternator stator temperature in °C.
  • Disconnect load bank and reconnect generator to the building distribution.
  • Demonstrate automatic starting of set and automatic transfer of load on failure of normal power and transfer on resumption of normal power.
  • Demonstrate operation of manual bypass switch in both directions.
  • Demonstrate automatic cool down and shut down of engine on resumption of normal power.
  • Demonstrate that battery charger reverts to high rate charge after cranking. Demonstrate two minute total cranking capacity and recharge cycle.
  • Demonstrate low oil pressure and high engine temperature shutdowns.
  • Simulate loss of normal power by de-energizing main distribution feeder breaker. Allow generator to operate with building loads. R-energize main distribution feeder breaker. Note operation of transfer switch and controls during the simulated power failure test.
  • All testing shall conform to testing standards - total of 6 hours.
• Guarantee
  
  • After the site testing is completed and all systems are operating satisfactorily, the system supplier shall submit a certification report and letter stating that the complete standby generator installation complies with the requirements of the manufacturer.
  • The standby generator equipment, as supplied and installed, shall be guaranteed for a period of two years from date of acceptance and turnover to the customer.
• On-site instructions.The generator set supplier shall provide on-site instruction to familiarize personnel with the operational techniques and preventative maintenance procedures for the system.
  • System description.
    
    • The standby diesel electric generating system shall include, but not necessarily be limited to, the following:
      
      • Diesel engine - generator set as described herein.
      • Starting batteries, exhaust silencer and manifold, flexible fuel lines, etc.
      • Engine/generator control and console and output disconnect breaker.
      • Transfer switch arrangement shall transfer the load from normal supply to emergency supply.
      • All necessary controls and devices to provide a complete operable automatic standby power system.
  • System operation.
    
    • Upon failure of the normal power supply the engine-generator set shall automatically start. Once generator voltage and frequency are within acceptable limits, the transfer switch shall operate to allow emergency power to be supplied to the emergency loads. Upon return of the normal power the load shall be re transferred to the normal power supply and the engine-generator set shall cool down and stop.
    • Engines shall start, achieve rated voltage and frequency, and transfer to the load within ten seconds of loss of normal power.
  • Engine.
    
    • Diesel engine.
    • Prime mover: full diesel 4 cycle, turbo charged, synchronous speed, 1800 rpm. Engine shall be capable of recovery from 0% to 100% instantaneous step load with maximum transient speed deviation of 10% (6 Hz) and recover to rated speed within 5 seconds.
    • Capacity: engine shall be capable of driving the specified generator on a continuous standby basis for duration of normal utility source interruptions for ambient conditions of 30°C, 101 kpa barometric pressure and 3000m elevation.
    • Cooling system: engine shall be liquid cooled via engine mounted radiator, engine driven fan and engine driven water pump. Provide a 50% ethylene glycol antifreeze/water coolant. Cooling system shall maintain manufacturer’s recommended engine temperature range at 10% continuous overload in ambient temperature of 38°C.
    • Engine coolant heaters: engine mounted, jacket water heater type, thermostatically controlled, 240V AC, single phase power liquid coolant heaters shall allow engine to start in room ambient temperature of 0°C.
    • Fuel system: solid injection, mechanical fuel transfer pump with hand primer, replaceable element fuel filters, fuel rack solenoid energized when engine running, fuel rail line check valve and fuel return line check valve. Fuel system shall be complete with all necessary valves, restrictors, check valves, seals, etc., as required and recommended by the supplier to suit the actual site fuel system. Engine shall operate on diesel fuel.
    • Governor: Electronic to provide isochronous regulation.
    • Lubrication system: pressure lubricated by engine driven oil pump with pressure regulation valve, replaceable element lube oil filter, lube oil cooler and engine sump drain valve. Engine shall have an oil level indicator, oil pressure gauge and low oil pressure shutdown switch.
    • Air cleaners: large capacity replaceable dry element type.
    • Starting system:
      
      • Positive shift, gear engaging stator 24V DC.
      • Cranking limiter to provide 3 cranking periods of 10s duration, each separated by 5s rest.
      • Lead acid, 24V heavy duty batteries with sufficient capacity to crank engine for 3 minutes at 0°C without using more than 25% of ampere hour capacity. Provide corrosion resistant mounting rack.
      • Battery charger: constant voltage, solid state, two stage from trickle charge at standby to boost charge after use. Regulation: +1% output for +10% input variation. Equipped with DC voltmeter, DC ammeter and ON-OFF switch.
    • Engine instrument panel: shall include lube oil pressure gauge, lube oil temperature gauge, coolant temperature gauge, running time meter.
    • Guards shall be integrally mounted on unit to protect personnel from hot and moving parts.
    • Drip tray.
    • Engine shall have water jacketed exhaust manifolds.
  • Generator.
    
    • Standard: to CSA C22.2 No. 100 and NEMA MGL.
    • Rating: 347/600V, 3 phase, 4 wire, 60 Hz, at 0.8 pf with 105°C temperature rise, 1800 RPM. Output capacity shall be as indicated on the drawings.
    • Generator: single-bearing, four-pole, drip-proof construction, synchronous type, revolving field, with direct drive centrifugal blower for cooling and minimum noise. Stator shall be skewed design and twice impregnated with high-temperature polyester varnish. Generator shall be directly connected to engine flywheel housing. Rotor shall be driven through a flexible coupling to insure permanent alignment. Rotor shall have amortisseur windings, and be vacuum impregnated with 100% solid epoxy resin, and shall be dynamically balanced.
    • Exciter: shall include a DC stator field with three-phase rotor, full wave, rectified, with heavy-duty encapsulated silicon diodes mounted on the common rotor shaft and sized for maximum motor starting.
    • Insulation: EEMAC Class F.
    • Voltage regulator: temperature compensated solid state, silicon controlled rectifiers with phase controlled sensing circuit:
      
      • Frequency regulation ±3% no load to full load.
      • Steady state voltage regulation ±1% no load to full load.
    • Voltage waveform deviation factor and telephone influence factor shall meet NEMA standards. Total harmonic content of the output waveform shall not exceed 5%.
    • A permanent magnet generator shall provide excitation power to the AVR to provide immunity from voltage distortion from non-linear loads.
  • Control panel.
    
    • Provide a unit mounted control console that is factory built, wired, tested and shock-mounted by the unit manufacturer. Control console shall be a rigid, ‘sprinkler proof’, metal enclosure, mounted on the generator end of the set, containing all devices as specified herein, and as required for described functions. Control console shall include a control section and control panel with required access to all components. Control wire shall have termination identification on each wire for ease of tracing. Control wires which run between generator set controls and automatic transfer switches shall have identical termination identification on both ends. Lamacoid nameplates shall be provided to identify each device or function..
    • Instruments:
      
      • Analogue indicating type 2% accuracy, rectangular scale, flush panel mounting: voltmeter: AC, scale 0 to 600V, ammeter: AC, scale 0 to 600 amps, frequency meter: scale 55 to 65 Hz.
      • Voltmeter selector switch, rotary, panel mounting, round notched handle, four position, labelled “OFF-AB-BC-CA”.
      • Ammeter selector switch, rotary, maintained contacts, panel mounting, designed to prevent opening of current circuits, round notched handle, four position labelled “OFF, A-Phase, B-Phase, C-Phase”.
      • Fuses for indicating instruments: miniature, glass, fast acting.
      • Oil pressure gauge.
      • Coolant temperature gauge.
      • Running time (hour) meter.
    • Controls:
      
      • Engine run-stop-auto switch..
      • Engine emergency stop button plus provision for remote emergency stop button.
      • Lamp test switch and reset switch.
      • Voltage adjusting control.
      • Frequency adjusting control..
    • Automatic shut-down lights and alarms:
      
      • Engine over crank (shutdown after 3 cranking attempts).
      • Engine over speed shutdown at 115%).
      • High engine temperature (shutdown at 120%).
      • Engine - low lube oil pressure (shutdown at 40%).
      • Short circuit and over current.
      • Low battery voltage continuously monitored even when engine not running. Auto reset alarm.
      • Alternator over voltage and under voltage (shutdown at 115% and 85% sustained for 5 seconds).
      • Low fuel level (alarm: connect to the building management system and remote annunciator).
      • Low coolant temperature (alarm at 20°C to 30°C).
      • Auxiliary contact for “not in auto” (alarm).
      • No battery voltage: provide a separate relay audible device and 240V AC power source.
      • Common alarm contacts (connect to the building management system and remote annunciator).
    • Remote annunciator:
      
      • Provide a remote annunciator with common alarm signal, low fuel alarm signal and silence switches. Locate in data centre operations area, unless otherwise indicated.
      • Wire and connect the following signals to Fire Alarm System Annunciator via Remote Addressable Monitoring Modules:
        
        • Low Fuel Alarm.
        • Generator Running.
        • Common Alarm.
    • Auxiliary contacts:
      
      • Three sets of N/O and N/C contacts for remote annunciator connection and control of mechanical ventilation within the generator room.
  • Automatic transfer switch.
    
    • Include two-single, 4-pole contactors mounted on common frame, in double throw arrangement, mechanically and electrically interlocked. Three switch positions shall be provided: normal, emergency and neutral.
    • Rated: [347/600V], 60 Hz. Current rating as indicated.
    • Main contacts: silver surfaced, blow on construction protected by arc disruption means including separate arcing contacts, arc splitters and blow out coils for load current.
    • Switch and relay contacts, coils, spring and control elements accessible for inspection and maintenance from front of panel without removal of switch panel or disconnection of drive linkages and power conductors.
    • Auxiliary contacts: to initiate emergency generator start-up upon failure of normal power.
    • Fault withstand rating: 42 kA symmetrical.
    • Selector switch - three position “Test”, “Auto”, “Manual”.
      
      • Test position - normal power failure simulated. Engine starts and automatic transfer takes place. Return switch to “Auto” to retransfer and stop the engine as per the control sequence.
      • Auto position - allows automatic operation of transfer switch to emergency upon failure of normal power; retransfers on return of normal power and shuts down engine, as per the control sequence.
      • Manual position - transfer switch may be operated by manual handle but transfer switch will not operate automatically and engine will not start.
    • Control transformers: dry type with a fused 24V secondary to isolate control circuits from:
      
      • Normal power supply.
      • Emergency power supply.
    • Relays: continuous duty, industrial control type, with wiping action contacts rated 10A minimum:
      
      • Voltage sensing, one per phase, solid state type: adjustable drop out (75%) and pickup (95%) close differential, 2V minimum under voltage, over voltage protection.
      • Time delay on engine starting to override momentary power outages or dips: adjustable from 1 to 6s; set at 3 seconds.
      • Time delay to initiate signal to transfer from standby to normal power, once normal power is available: adjustable 5 minutes to 30 minutes; set at 10 minutes.
      • Time delay on transfer from the neutral position to normal power to allow the residual voltage on motor loads to decay to a safe level before retransfer: adjustable 0.5 seconds to 5 seconds; set at 1.0 seconds (ASCO switches shall be provided with an in-phase monitor for retransfer operation).
      • Time delay for engine cool-off shall permit standby set to run unloaded after retransfer to normal power: adjustable 5 minutes to 30 minutes. Set at 5 minutes.
      • Frequency sensing, shall prevent transfer from normal power supply until frequency of standby unit reaches preset value.
    • Pilot light shall indicate switch position, green for normal, red for emergency.
    • Three normally open and three normally closed auxiliary contacts.
    • Sheet steel “sprinkler proof” enclosure.
  • Bypass isolation switch.
    
    • As shown on the drawings, specified transfer switches shall be included in a factory assembly with bypass-isolation switch equipment. The bypass-isolation switch shall provide a safe means for manually bypassing the transfer switch from either source (Normal or Emergency) to the load, while under load if necessary, and isolating the transfer switch from both sources for maintenance or repair. Two source bypass is a requirement. Designs which bypass to only one source are not acceptable under this specification.
    • By-pass isolation switch equipment shall be certified with continuous current rating, voltage and frequency ratings, and withstand and closing ratings equal to the transfer switch ratings at the specified conditions of ambient temperature, humidity and altitude.
    • Bypass switch shall be a fully rated, manually operated switch, rated for the same loads as the automatic transfer switch.
    • Positive mechanical interlocks shall prevent all possible source to source connections. Designs depending on electrical interlocks to prevent source to source connections, or which intentionally interconnect the sources are not acceptable.
    • Isolating contacts in the draw out isolation mechanism shall allow the automatic transfer switch to be separated electrically and mechanically. The isolation mechanism shall be interlocked so that either the transfer switch must be bypassed or the transfer switch must be open before the mechanism shall permit transfer switch isolation. The draw out mechanism shall provide for three-position operation; CONNECTED, TEST and ISOLATED. These positions shall be shown on the draw out position indicator. In the CONNECTED position isolation contacts shall be fully engaged and closed with the automatic transfer switch control cable connected. In the TEST position isolation contacts shall be open, with the transfer switch control cable connected. The TEST position shall allow operational testing of the automatic transfer switch and the controls without power disruption to the load. In the ISOLATED position the automatic transfer switch and the control shall be completely isolated from all power sources. In this position safety shutters shall close to cover bypass power terminals for operator safety. Once isolated, the automatic transfer switch shall be capable of being completely withdrawn from the cabinet for inspection or service without disconnection of power cables. When re-installing the transfer switch from the isolated position, the isolation mechanism shall not permit connection of the transfer switch unless it is in the open position, and shall automatically open the transfer switch if necessary regardless of the availability of electrical power. When the transfer switch is fully connected and locked in place, the mechanism shall move the transfer switch from the open position to the closed position on the same source as the bypass switch.
    • The free-standing enclosure shall be a welded construction sprinklerproof steel cabinet. Wire bend space shall comply with electrical standards for the maximum size and number of conductors the terminal lugs will accept. A key locking handle shall be provided. Front panel mounted controls shall require use of a key.
  • Generator output disconnect.
    
    • Provide a [600V] output circuit breaker, complete with shunt trip as indicated, to disconnect the output circuit of the generator.
  • Charger and batteries.
    
    • Provide solid state, duel rate, automatic battery charger with voltmeter and ammeter.
    • Provide a battery rack and 24V DC lead acid battery and cables.
  • Structural steel mounting base
    
    • Complete generating set mounted on structural steel base of sufficient strength and rigidity to maintain proper alignment between components during transportation, installation and under operating conditions. Include vibration isolators to isolate moving parts from the steel base. Steel spring isolators shall be provided on the base to provide suitable mounting to a level surface.
  • Exhaust system.
    
    • Include heavy duty, critical type, horizontally mounted exhaust silencer, with condensate drain, plug and flanged couplings.
    • Include suitable length of heavy duty flexible exhaust hose with flanged couplings for connection between exhaust manifold and exhaust line.
  • Fuel system.
    
    • Include flexible connections for connecting fuel lines to engine. Include auxiliary float controlled fuel reservoir on engine to accommodate mounting of the main fuel tank above line of injectors (if applicable).
    • Provide a day tank with float switch of minimum capacity as recommended by generator set manufacturer. Tank shall be new and unused and shall not be galvanized.
    • A 1000 litre main fuel tank, complete with rack, shall be provided. The tank shall be provided with a float switch for low level alarm indication (set float at point where 3/4 hour of fuel is left). The low level alarm shall be connected to an audible and visual indicator on the engine control panel and remote annunciator. The audible indicator at the remote annunciator shall have a silence switch. The tank shall also be provided with an exterior weatherproof high level alarm, complete with weatherproof silence switch, activated by a high level float switch for filling purposes.
    • Fuel transfer pumps that may be required shall be provided. Pumps shall be of sufficient lift and capacity to deliver fuel in excess of maximum fuel consumption rate of the engine from the main storage tank to the day tank. Day tank float switch shall cycle pumps to control fuel level in day tank.
  • Cooling system.
    
    • Remote mounted industrial radiator, complete with electric fan. Assemble unit on steel frame. Include vibration isolators. Size of radiator, fan and motor shall be compatible with cooling capacity required.
    • Provide an LCL sensor to shutdown the engine in the event of a total loss of coolant.
  • Accetable manufacturers.
    
    • Caterpillar.
    • Onan.
    • Midwest Detroit Diesel.
    • Kohler.
    • John Deere.
    • Perkins.
  • Equipment Identification.
    
    • Provide equipment identification.
    • Control panel and transfer switch:
      
      • Nameplates for controls..
      • Nameplates for meters, alarms, indicating lights.
  • Fabrication.
    Shop assemble generating unit including:
    
    • Base.
    • Engine.
    • Generator.
    • Control panel.
    • Remote radiator.
  • Fluids.
    
    • Provide lube oil and antifreeze.
    • Provide diesel fuel, as recommended by the manufacturer.
• Installation.
  
  • Locate generating unit, remote radiator and all associated equipment and install as indicated.
  • Wire and connect all equipment and controls.
  • Installation of exhaust fan, ventilating air duct system, motorized dampers on air intake and discharge grilles, and room temperature controls.
  • Installation of main fuel tank, pumps and supply, vent and fill lines.
  • Wire and connection of float controls.
  • Installation of silencer, exhaust piping and high temperature insulation.
  • Silencer shall be mounted such that its weight is not supported by the engine. Condensate drain on the silencer shall be connected to the nearest floor drain.
  • Provide branch circuit wiring for block heaters, battery charger, fuel transfer pumps and remote radiator fan.
  • Provide all required fuel for testing. Top up fuel tank upon completion of testing.
  • Install, wire and connect remote annunciator.
  • Installation shall meet the requirements of the building standards.
  • Coordinate with the contractor to mount the generator set on a 100 mm high concrete housekeeping pad.
  • Coordinate installation with site conditions. Disassemble and reassemble as required to place genset as indicated.
• Testing
  
  • Furnish all necessary equipment, labor, instruments, etc. as needed to perform testing.
  • Verification Report.
• Sign-off
  
  • Conformance of installation, wiring, protection and grounding of the electrical equipment with electrical standards.
  • Conformance with relevant engine standards.
  • Conformance with relevant safety standards.
  • Location of generator set in conformance with building code.
  • Vibration.
  • Ventilation.
  • Temperature.
  • Unit equipment for emergency lighting.
  • Control Sequence.
  • Engine horsepower rating.
  • Fuel supply.
  • Engine control panel.
  • Cranking cycle.
  • Storage batteries.
  • Compressed air pressure.
  • Generator construction.
  • Generator performance.
  • Exciter.
  • Voltage regulator.
  • Voltage build-up.
  • Overcurrent protection.
  • Generator controls.
  • Transfer switch.
  • Manual by-pass switch.
  • Initial installation performance test.

A mindmap of the Standby generator Checklist.

This article was originally published over at LinkedIn: Standby Generator Checklist - useful for data centre standard operating procedures