21750045 Volvo.Penta Thermostat housing

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.
Illustration 1 g01195134
Connections for the Voltage Regulator
(G) Generator
(ST1) The jumper wire ST1 must be removed for correct operation of the R 731.
(ST9) The jumper wire ST9 must be removed for a permanent magnet generator.
(ST10) The jumper wire ST10 must be removed for correct operation.The R438 voltage regulator and the R731 module for sensing three-phase voltage are located in the enclosure for the control panel.The supply for the excitation system is provided to the R438 by the PMG. An additional R731 module for sensing three-phase voltage is connected to the low voltage output .The voltage regulator has a remote potentiometer for voltage adjustment. This potentiometer is on the control panel.R438 Adjustments
Table 1
R438 Automatic Voltage Regulators
Maximum current for short circuit 3 x In for 10 seconds
Standard power supply PMG
X1, X2, Z2
Rated overload current 8 amperes for 10 seconds
Electronic protection for overload and short circuit opening on voltage sensing Excitation ceiling current for 10 seconds and return to approximately 1 ampere
THE GENERATOR MUST BE STOPPED IN ORDER TO RESET THE PROTECTION.
Fuse "F1" on input side "X1" and "X2"
Fuse "F2" on output side "E+" and "E-"
Voltage sensing 5 VAC that is isolated by the transformer
Terminals for 0 to 220 VAC 170 to 260 ACV
Voltage regulation 1%
Rapid response time or normal response time from the location of jumper "ST2"
Voltage adjustment via potentiometer "P2"(other voltages via the step down transformer)
Underspeed protection and adjustment of frequency threshold via potentiometer "P4"
Maximum adjustment for excitation via potentiometer "P5" (4.5 to 10 amperes)
50 or 60 Hz selection with jumper "ST3"(1).
(1) The engine speed setting must be changed to change the frequency of the generator set.
Illustration 2 g00952512
Illustration 3 g00952515
R438 connections
Use the following procedure to adjust the R438 voltage regulator.
Remove wire ST4.
Connect an analog voltmeter that is calibrated for 50 VDC on terminal E+ and terminal E-.
Connect a voltmeter that is calibrated for 300 VAC to 500 VAC or 1000 VAC.
Make sure that the ST3 wire is positioned on the desired frequency.
Turn potentiometer (P2) to a full counterclockwise position.
Turn potentiometer (P4) to a full clockwise position.
Turn potentiometer (P3) counterclockwise to about 1/3 of the total rotation for the potentiometer.
Start the engine and set the engine speed to a frequency of 48 Hz for 50 Hz or 58 Hz for 60 Hz.
Adjust the output voltage to the correct value with potentiometer P2. This voltage should be the rated voltage UN for single operation or UN plus 2% to 4% for parallel operation. Use potentiometer P3 to make adjustments if the voltage oscillates. Adjust potentiometer P3 in both directions while you observe the voltage between E+ and E-. The voltage between E+ and E- should be approximately 10 VDC. The best response times are obtained at the limit of the instability. Try cutting or replacing the wire ST2 if no stable position can be obtained.
Check the LAM operation. ST5 must be closed.
Turn potentiometer (P4) slowly counterclockwise until there is a significant voltage drop. The voltage drop should be approximately 15 %.
Vary the frequency of both parts between 48 Hz or 58 Hz according to the operating frequency. Check the change in the voltage that was previously observed.Use the following procedure to run the generator set in parallel operation.
Preset the unit for parallel operation by connecting the current transformer to S1 and S2 of the connector J2. Set potentiometer P1 for quadrature droop in the center position. Apply the rated load. The voltage should drop for 2% to 3%. Switch the positions of the two incoming secondary wires of the current transformer if the voltage increases.
The no-load voltages should be identical for all the generators that are operating in parallel. Connect the generators in parallel. Try to obtain a 0 kW power exchange by adjusting the speed of the generat