stamford avr AS480
This AVR is specifically designed to fit into and work with the P0 &P1 generator, it is the only AVR that fits into the terminal box and is capable of working with the optional Excitation Boost System (EBS).
The following 'jumper' connections on the AVR should be checked to ensure they are correctly set for the generating set application.
Control Function Direction
VOLTS Generator output voltage setting Clockwise raises voltage
STABILTY Output voltage stability Clockwise increases stabilization effect
DROOP Voltage droop for paralleling Clockwise increases drooping effect
UFRO Under-frequency 'Knee' point Clockwise decreases 'Knee' point
Refer to the Generator Wiring Diagrams for all Connection detail
Main Stator Powered AVR
The main stator provides power for excitation of the exciter field via the SX480 AVR which is the controlling device governing the level of excitation provided to the exciter field. The AVR responds to a voltage-sensing signal derived from the main stator winding. By controlling the low power of the exciter field, control of the high power requirement of the main field is achieved through the rectified output of the exciter armature. The AVR senses average voltage on two phases ensuring close regulation. In addition it detects engine speed and provides voltage fall off with speed, below a pre-selected speed (Hz) setting, preventing over-excitation at low engine speeds and softening the effect of load switching to relieve the burden on the engine. The detailed function of the AVR circuits and their adjustment are covered in the load testing section.
Optional excitation Boost system (EBS)
The EBS is a single, self-contained unit, attached to the non-drive end of the generator.
The EBS unit consists of the Excitation Boost Controller (EBC) and an Excitation Boost Generator (EBG).
Under fault conditions, or when the generator is subjected to a large impact load such as a motor stating, the generator voltage will drop. The EBC senses the drop in voltage and engages the output power of the EBG. This additional power feeds the generator's excitation system, supporting the load until breaker discrimination can remove the fault or enable the generator to up a motor and drive the voltage recovery.