5X00481G01 analog output module

For example, assume there is a 480 volt line-to-line generator set operating in a system that uses 4:1 voltage transformers to feed the EGCP-2. The input AC line to line voltage at the EGCP-2 is 118 volts due to primary to secondary losses across the voltage transformers. The EGCP-2 Generator Status menu will display a generator voltage of 472 Vac L-L for each phase, which is not truly what the generator is producing. In this case, the Calibration tuning menu would be used to adjust the A/D converters on the three generator voltage transformer inputs until the Generator Status menu reads 480 Vac L-L for each phase. This is how the calibration menu is used to compensate for losses in signal between the source, and the EGCP-2. The calibration menu allows adjustment of all the analog inputs and outputs of the EGCP-2.

Calibration of Generator PTs and CTs 

The Calibration menu of the EGCP-2 contains calibration adjustments for three phase generator voltage and current. These calibration adjustments are labeled as follows: PT Phase A Scale Calibrates the A phase generator PT input. Menus Affected Changes in the calibration set point will change the generator A phase voltage as seen on the Generator Status screen. Changing this value will also have an effect on generator kW and kVAR levels. The generator A phase voltage is also used as part of the function that determines when the generator is stable as shown in the System Status menu by a ++ following the GEN label. If the generator A phase PT is not properly calibrated, the level at which the generator is shown as stable may not be a true indication of a stable condition.

Operations Affected 

The EGCP-2 uses the A phase generator voltage for voltage matching when synchronizing across the generator breaker. Accurate calibration of the Generator A phase PT is critical for proper voltage matching operation. The sensed generator voltage on the A phase is used in Power Factor/VAR sharing mode when the EGCP-2 is in parallel with other units on an isolated bus. The EGCP-2 uses the Voltage Reference as found in the Configuration tuning menu as a generator voltage reference point when balancing the reactive load on the bus between generators. If the A phase PT voltage is out of calibration at the EGCP-2 the bus voltage may be off of this reference when in Power Factor/VAR sharing mode. Also, poor VAR/PF sharing may occur if the A phase PT is not properly calibrated. Generator Voltage is also used in real and reactive load calculations. These calculations are used in all real and reactive power control functions.