2a762 Volume 1 Ure Part 2

The injector pump is the component on the B809A generator set fuel system that distributes and delivers an accurate amount of fuel to the engine cylinders. It is responsible for pressurizing the fuel and delivering it to the injectors, which then atomize the fuel and inject it into the engine cylinders for combustion. The injector pump plays a crucial role in ensuring the proper fuel-air mixture for efficient engine operation.

The best point to check voltage to the -86D exciter field is at J8, terminal D-F. This is because J8 is the designated terminal for checking voltage in this circuit, and the D-F terminals specifically correspond to the exciter field. Therefore, checking voltage at J8, terminal D-F would give the most accurate and relevant measurement for the exciter field.

The torsion shaft is specifically designed to break if the engine locks up. This component is responsible for transmitting torque from the engine to the compressor and fan blades. If the engine locks up, it can cause a sudden increase in torque, which can lead to catastrophic failure of the engine. By designing the torsion shaft to break, it acts as a safety mechanism, preventing further damage to the engine and reducing the risk of a complete engine failure.

The probable cause of the excessively high exhaust gas temperature in a -60A could be a malfunctioning pneumatic thermostat. The pneumatic thermostat is responsible for regulating the temperature of the engine by controlling the flow of air or fuel. If it is not functioning properly, it may result in an imbalance in the fuel-air mixture, leading to higher exhaust gas temperature.

The scavenge pump is responsible for drawing excess oil from the gear case in the -60A lubrication system on a gas turbine engine. This pump is designed to remove any oil that is not being used for lubrication and return it to the oil tank for recirculation. By doing so, the scavenge pump helps to maintain the proper oil level and prevent any potential damage or malfunction caused by an excess of oil in the gear case.

The low coolant light (DS50) illuminates but the unit does not shut down because S55 is closed and S48 is closed.

Switch S15 to the L-N position. This is the correct answer because when an AC voltmeter is reading 200 VAC on all three phases, it indicates that the voltmeter is connected in a delta configuration. Switching S15 to the L-N position will change the configuration to a wye configuration, which is the correct configuration for measuring voltage in this scenario. Adjusting VR1 or R61 would not address the issue of incorrect configuration.

The probable cause of the voltage not building up when operating -86D at governed speed is that the K23 contacts are open.

The probable cause of the undervoltage light coming on when placing S13 in the build-up position while operating a -86D at governed speed is the memory time delay relay. The memory time delay relay is responsible for delaying the response of the undervoltage relay to prevent false alarms during momentary voltage fluctuations. In this case, it seems that the memory time delay relay is not functioning properly, causing the undervoltage light to come on when it shouldn't.

The correct answer is low lube pressure. The low lube pressure safety circuit in the B809A generator set engine incorporates a seven-second time delay before activation. This delay allows the engine to reach a safe operating temperature before shutting down due to low lubrication pressure. This feature helps prevent unnecessary engine damage and ensures the longevity of the generator set.

Apparent power is a measure of the total power in an electrical circuit, taking into account both the real power (in kilowatts) and the reactive power (in kilovolt-amperes). It is denoted as kilo-volt-amperes (KVA). This measurement is important in determining the overall power capacity and efficiency of electrical systems, as it considers the effects of both active and reactive components of power. Kilovolts (KV) and kilowatts (KW) are not accurate measurements for apparent power as they do not account for the reactive power component. Kilo-watt-amperes (KWA) is not a standard unit of measurement for apparent power.

CR2 supplies 28 VDC to operate the panel lights, wind switch assembly, and AC voltmeter. The blower motor B2 is also supplied by CR2. Therefore, the correct answer is blower motor B2.

The voltage regulator VR1 controls the strength of the -86D exciter field L2. This means that VR1 is responsible for regulating the voltage supplied to the exciter field, which in turn determines the strength of the field. By adjusting the voltage, VR1 can control the level of excitation in the field, allowing for precise control over the generator's output.

A probable cause of the trouble is that S30 is shorted. This means that there is a direct connection between the terminals of S30, causing a short circuit. As a result, the fault lights on the -86D power unit remain on even after attempting to reset S23. This suggests that the issue lies with S30 rather than S23 or any other component mentioned in the options.

When the B809A generator set AC card senses an AC supply fault, the AC contactor opens and the generator output stops. This means that the AC contactor, which is responsible for connecting and disconnecting the generator set to the AC supply, opens to disconnect the generator from the faulty AC supply. As a result, the generator output also stops because it is no longer connected to the AC supply. This action helps to prevent any further damage or issues that may arise from the faulty AC supply.

The probable cause of the trouble is the governor trim control. The governor trim control is responsible for adjusting the speed of the engine to maintain a constant RPM. If the unit is only operating at 97 percent, it suggests that the governor trim control is not functioning properly and is not able to maintain the desired speed.

The contacts on the annunciator card of the B809A generator set that control the AC power input to the voltage regulator are the generator fault contacts. These contacts are responsible for detecting any faults or issues with the generator, which in turn affects the power input to the voltage regulator. If there is a fault with the generator, it can disrupt the AC power input to the voltage regulator and potentially cause issues with the overall functioning of the generator set.

The DC card on the B809A generator set senses the condition of overtemperature. This means that the card is designed to detect and monitor the temperature of the generator set, and if it exceeds a certain threshold, it will trigger an alarm or shutdown to prevent any potential damage or malfunction caused by overheating.

The probable cause of the fuel coming out of the main tank fuel cap is that S20B failed to close.

The probable cause of the DC voltmeter on a -60A failing to indicate during operation is that TR1 is defective.

The power factor meter is used during performing resistive and reactive load tests simultaneously. This is because resistive load tests only measure true power, while reactive load tests measure both true power and apparent power. The power factor meter is necessary in this scenario to accurately measure the power factor, which is the ratio of true power to apparent power. By using the power factor meter, it is possible to determine the efficiency and effectiveness of the load bank in handling both resistive and reactive loads simultaneously.

The probable cause of the blower motor not working on the load bank after connecting a -60A to the -8 load bank is CR2.

The correct answer is S5, run/idle toggle switch. When operating a B809A generator, closing the run/idle toggle switch will provide potential to the exciter field. This switch controls the generator's operation by toggling between the run and idle modes. By closing this switch, the exciter field is energized and allows the generator to produce power.

The oil pressure relief valve controls the output of the main oil pump by bypassing excess oil back to the main pump inlet. This means that if the oil pressure exceeds a certain limit, the relief valve opens and allows the excess oil to flow back into the pump inlet, preventing any damage or malfunction due to excessive pressure. By diverting the excess oil, the relief valve helps to regulate and maintain a consistent oil pressure within the lubrication system of the gas turbine engine.

The probable cause of the trouble is that D1 is open. This means that the diode D1 is not allowing voltage to reach R6, which could be causing the dead batteries.

The shutdown solenoid energizing immediately after the engine run indicator illuminates could be caused by S49 being shorted. This means that there is a direct connection between the two components, causing the solenoid to activate as soon as the engine run indicator turns on.

If S46 shorts during operation of a -86D generator, 12 VDC would be present at terminal A of S55.

The operating voltage of the blower motor and control relays on a -8 load bank is 28 VDC.

The probable cause of the trouble is that the memory time-delay relay is energized. This relay is designed to introduce a delay in restoring power after a power interruption or fault. In this case, the relay has been activated, causing a delay in the restoration of voltage to M2. This could be due to a malfunction or a deliberate activation of the relay.

The regulator card output pulse sent to the exciter field of the B809A generator is powered by 110 VDC.

The probable cause of the trouble is that the contacts C and D of K11 have opened. This means that there is a break in the circuit, preventing the flow of electricity to the AC contactor light. As a result, even though S3 is closed, the light does not come on.

The probable cause of the trouble is that R46 is open. This can be inferred from the given information that when S5 is placed in the closed position, the contactor light illuminates, but when the switch is released, the contactor opens. This behavior indicates that there is an issue with the circuit, and the most likely cause is that R46, which is responsible for maintaining the closed circuit, is open.

The probable cause of the trouble is that S53 is open. This means that the switch S53, which is responsible for generating a response when placed in the GENERATE position, is not functioning properly. This can be deduced from the fact that there is a 12-volt direct current (VDC) at J8, terminal N, indicating that the power supply is working fine. Therefore, the issue lies with the open switch S53, which is preventing the desired response from occurring.

The rate adjustment screw in the -60A is used to adjust the rate at which chamber 4 depressurizes.

The probable cause of this trouble is that CR1 is malfunctioning. CR1 refers to a component or relay that is responsible for controlling the shock load switches. If CR1 is malfunctioning, it means that it is not functioning properly and is unable to activate the shock load switches, resulting in nothing happening when they are turned on.

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If CB2 opens on the -8 load bank, it will cause the AC load selection switches (S15 through S20) to not work.

The probable cause of the engine rotating but no combustion during operation of the -60A is issue with the ignition system.

When operating a -60A, resetting the AC contactor switch should have caused the K11B relay to energize, closing the N and P contacts. This means that the correct answer is K11B energized, closing N and P contacts.

CB2 supplies 28 VDC to the variable load selector switches on a -8 load bank.

The probable cause of the trouble is that S18 is closed. This means that the switch S18, which is responsible for starting the unit, is in the closed position. This would prevent the unit from starting as it should be in the open position for the unit to start.

The probable cause of the trouble is the turbine control relay K18. When the start switch S7 is released, the turbine engine shuts down immediately. This suggests that the turbine control relay K18 is not functioning properly and is not able to maintain the power to the engine after the start switch is released.

You should start troubleshooting at K2.