850047 Volvo.Penta Electric motor

Personal injury or death can result from high voltage.When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present.Improper test equipment can fail and present a high voltage shock hazard to its user.Make sure the testing equipment is designed for and correctly operated for high voltage and current tests being made.When servicing or repairing electric power generation equipment:
Make sure the unit is off-line (disconnected from utility and/or other generators power service) , and either locked out or tagged DO NOT OPERATE.
Remove all fuses.
Make sure the generator engine is stopped.
Make sure all batteries are disconnected.
Make sure all capacitors are discharged.Failure to do so could result in personal injury or death. Make sure residual voltage in the rotor, stator and the generator is discharged.
Accidental engine starting can cause injury or death to personnel working on the equipment.To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system.Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.
The voltage regulator is located in the enclosure for the control panel or in the terminal box on the generator.The Automatic Voltage Regulator (AVR) may control any of the following excitation systems: AREP, PMG and SHUNT. The AVR monitors and corrects the alternator output voltage by adjusting the excitation current.
Illustration 1 g03368326
The voltage regulator is located in the terminal box on the generator or in the enclosure for the control panel.
(1) Terminal Box on the Generator
(2) Enclosure for the Control PanelThe generator set may include one of the following voltage regulators.SHUNT excitation system
The generator with SHUNT excitation is auto-excited with an R220, R250, or R251 voltage regulator. The regulator monitors the exciter excitation current as a function of the alternator output voltage.AREP excitation system
For both AREP and PMG excitation systems, the AVR is the R438. With AREP excitation, the R438 electronic AVR is powered by two auxiliary windings which are independent of the voltage match circuit.The first winding has a voltage in proportion to that of the generator (characteristic SHUNT), the second has a voltage in proportion to the stator current (compound characteristic: Booster effect).The power supply voltage is rectified and filtered before being used by the AVR monitoring transistor. This principle ensures that regulation is not affected by distortions generated by the load.R250 Adjustments
Table 1
R250 and Regulator
Voltage regulation 0.5%
Voltage detection range 85 to 139 V (50/60 Hz)
Rapid response time for a transient voltage variation amplitude of 20% 500 ms
Voltage setting "P1"
Stability setting "P2"
8 Amp Fuse for protection of the power supply 10 amperes for 10 seconds
50 or 60 Hz selection is made using the frequency selector shown in illustration 3.
Illustration 2 g03361909Use the following procedure to adjust the R250 voltage regulator.
The engine speed must be changed from the factory setting in order to change the frequency of the generator.
Turn potentiometer P1 to the full counterclockwise position.
Turn the potentiometer ST4 to the middle of the total rotation for the potentiometer , if equipped. Run the generator at the rated speed. If the voltage does not increase, the field may need to be energized. Refer to the "Special Use" section.
Turn potentiometer P1 until the rated output voltage is obtained.
Adjust the stability with potentiometer P2.U/F Function and LAM
Illustration 3 g03363529
Frequency selector
The threshold position (50 Hz - 60 Hz) to activate the U/F function, as well as the LAM setting, is selected using the frequency selector.Operating at 50 Hz: (U/F gradient)
0 - Threshold at 48 Hz without LAM for impacts between 30 and 40% of the rated load.1 - Threshold at 48 Hz with LAM 13% for impacts between 40 and 70% of the rated load.2 - Threshold at 48 Hz with LAM 25% for impacts greater than 70% of the rated load.Operating at 60 Hz: (U/F gradient)
3 - Threshold at 58 Hz without LAM for impacts between 30 and 40% of the rated load.4 - Threshold at 58 Hz with LAM 13% for impacts between 40 and 70% of the rated load.5 - Threshold at 58 Hz with LAM 25% for impacts greater than 70% of the rated load.Special operating
6 - Threshold at 57 Hz without LAM for speed variations at a steady state greater than 2 Hz.7 - Threshold at 65 Hz without LAM for variable speed and tractelec/gearlec (U/F gradient).8 - Special. The factory setting 48 Hz 2 U/F gradient.9 - Threshold at 47.5 Hz without LAM for speed variations at a steady state greater than 2 Hz.R450 Adjustments