Product Manual A

4. Operation11-2017

4.4.2.1 Generator Set Under-Voltage and Under-Frequency Set Points

TABLE 4. GENERATOR SET UNDER-VOLTAGE AND UNDER-FREQUENCY SET POINTS

Description Set Point

Under-voltage Pickup

(% of Nominal)

90%

Under-voltage Dropout

(% of Nominal)

75%

Under-frequency Pickup

(% of Nominal)

90%

Under-frequency Dropout

(% of Nominal)

75%

4.4.3 Phase Check Sensor

The phase check sensor can be enabled (set to ON) for applications that require a fast transfer of a load

between two live sources (both Power Source Available LEDs are lit). The phase check sensor

determines when the relative phase difference (less than 25° and approaching 0°) and the frequency

differences (less than 1 Hz) of the two sources are within specified limits. When all conditions are met, a

transfer is initiated.

If enabled, the phase check sensor is activated after all time delays have expired, just before the transfer

switch transfers the load, and only when both sources are available.

4.4.4 Return to Programmed Transition

This feature can be used in conjunction with the phase check sensor. If, for some reason the two sources

do not fall within the specified limits of the phase check sensor for a period of two minutes, then the

control bypasses the phase check sensor, returns to the Programmed Transition sequence of operation

and transfers the load.

If this feature is enabled, the Programmed Transition Time Delay (TDPT) should be set greater than zero.

The actual setting depends on your load.

4.5 Generator Set Exerciser

There are two exercise clock options, A049B864 and 0307-3053. Please refer to the appropriate section

for further details on your model: Section 4.6 for A049B864 and Section 4.7 for 0307-3053.

4.5.1 General Information

Run the generator for at least 30 minutes once each week with at least 50% load (if possible). If you do

not want to use the exerciser, use the Test switch, to test the generator set each week.

The control includes an integrated exerciser that is set by pressing the Set Exercise pushbutton. In

addition, there may also be an optional fully programmable external exerciser clock installed and wired to

a control input.

If both types of exercisers are available, only one exerciser can operate at a time. The control panel must

be configured for the type of exerciser being used. This is done by setting the External Exerciser function

ON or OFF.

• If the integrated exerciser is used, the External Exercise ON/OFF function must be set to OFF.