INSULATION 4435006 - Caterpillar

Illustration 1 g00844487
R438 Voltage Regulator
Illustration 2 g00844489
R438 Voltage Regulator with components
The voltage regulator is powered by two auxiliary windings. These windings are independent from the circuit for detection of voltage. The first winding is labelled as "X1" and "X2" in illustration 2. This winding has a voltage that is proportional with the output voltage of the generator. The second winding is labelled as "Z1" and "Z2" in illustration 2. This winding has a voltage that is proportional to the current of the stator. The voltage from the power supply is rectified and filtered before being used by the regulator monitoring transistor. This principle ensures that regulation is not affected by interference that is generated by the load.
Table 1
Short circuit current 3 x In for 10 seconds
Standard power supply Two auxiliary windings
Shunt supply max 48V at 50/60 Hz
Rated overload current 8 amperes for 10 seconds
Electronic protection (overload, short-circuit opening on voltage detection) Excitation ceiling current for 10 seconds than 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 detection 5 ACV isolated by the transformer
0-110 ACV terminals 95 to 140 ACV
0-220 ACV terminals 170 to 260 ACV
0-380 ACV terminals 340 to 520 ACV
Voltage regulation 1%
Rapid or normal response time via strap "ST2"
Voltage adjustment via potentiometer "P2"(other voltages via the step down transformer)
Underspeed protection and frequency threshold adjustment via potentiometer "P4"
Maximum excitation current adjustment via potentiometer "P5" (4.5 to 10 amperes)
50 or 50 Hz selection via jumper "ST3" The voltage regulator has an optional remote voltage adjustment potentiometer. This potentiometer is 450 ohms, 0.5W minimum. The adjustment range is 5%. The range is limited by the internal voltage potentiometer "P2". Remove "ST4" to connect the potentiometer. A 1000 ohm potentiometer can also be used to extend the adjustment range.