CORE AS-RADIATOR 4226988 - Caterpillar

"AREP" Excitation System
The electronic AVR is powered by two auxiliary windings which are independent of the voltage sensing circuit.The first winding has a voltage proportional to the alternator main voltage ("SHUNT" characteristic). The second winding has a voltage proportional to the stator current (compound characteristic: Booster effect).The power supply voltage is rectified and filtered before being used by the AVR monitoring transistor. The excitation principle provides the generator set with a short circuit current overload capacity of 3 IN for 10s. The rotating switch should be in the "SHUNT/AREP" position."PMG" R 450 AVR
Illustration 5 g02173879"PMG" Excitation System
With PMG excitation, a PMG added to the alternator supplies the AVR with voltage which is independent of the main alternator winding. The AVR monitors the alternator output voltage by adjusting the excitation current. Excitation principle provides the machine with a short circuit current overload capacity of 3 IN for 10s. The rotating switch should be in the PMG position.Set-up
A qualified engineer must make adjustments during tests of the AVR. The drive speed specified on the nameplate must be reached before starting the adjustment. After operational testing is completed, replace all access panels and covers.The AVR adjusts the equipment.
Before using the AVR, correctly configure the rotating switches with AREP/SHUNT or PMG excitation.
Initial Potentiometer Settings
"P1" - Voltage minimum fully anti-clockwise (Factory setting 400V - 50 Hz)
"P2" - Stability (Not set)
"P3" - Excitation ceiling (Factory-sealed) 10 Amp maximum
"P4" - Voltage quadrature droop (Operation with current transformer) 0 quadrature droop fully anti-clockwise (Not set (fully anti-clockwise))Stability Adjustments (Stand Alone Operation)
Install a DC analogue voltmeter (needle dial) calibrated 100 V on terminals "F+", "F-" and an AC voltmeter calibrated 300 to 500 V or 1000 V on the alternator output terminals.
Check the rotating switch selection.
Voltage potentiometer "P1" at minimum, fully anti-clockwise.
Stability potentiometer "P2" around 120° from the anti-clockwise stop.
Start the engine. Set the speed to a frequency of 48 Hz for 50 Hz or 58 Hz for 60 Hz.
Set the output voltage to the desired value using "P1".
Rated voltage for solo operation (such as 400 V)
Or rated voltage (such as 410 V−)
If the voltage oscillates, use "P2" to make adjustments. Adjustments may be made in both directions. Observe the voltage between "F+" and "F−", which is approximately 10 VDC. The best response time is obtained at the limit of the instability. If no stable position can be obtained. select the fast position.
Check the LAM operation depending on the rotating switch selection.
Vary the frequency below 48Hz or 58 Hz according to the operating frequency. Check the change in voltage from the voltage observed previously.
Readjust the speed of the generator set to the rated no-load value. Stability Adjustments (Parallel Operation)
Note: Make sure that the speed droop is identical for all engines before working with the alternator.
Preset for parallel operation with the current transformer connected to "S1", "S2". Note: Potentiometer "P4" (quadrature droop) in 1/4 position in the case of 5A CT and at 1/2 position in the case of 1A CT.Apply the rated load (PF = 0.8 inductive). The