Basler Electric CBS 212A - Manual (Page 19)

9270700990 Rev F 13
Calibration
CBS 212A calibration consists of positioning the Sensing Voltage Select and Output Limit Select jumpers,
and adjusting the Output Limit Adjustment and Operating Point Adjustment controls. The following
procedures should be performed before placing the CBS 212A into service.
Sensing Voltage Selection
Configure the CBS 212A for the level of sensing voltage that will be applied to terminals TB1-3 and 4.
•
For sensing voltage of 90 to 139 Vac, use the 120 Vac jumper position. Connect the Sensing
Voltage Selection jumper across terminals TB2-10 and 11.
•
For sensing voltage of 180 to 277 Vac, use the 240 Vac jumper position. Connect the Sensing
Voltage Selection jumper across terminals TB2-9 and 11.
Output Limit Selection
Configure the CBS 212A for the level of field forcing voltage required to support a short-circuited
generator output.
1. Determine the level of field current required to sustain generator output during a short-circuit
condition. This value of current can be found in the generator manufacturer’s short-circuit
saturation data (plot of exciter field current versus line current with the generator output short-
circuited).
2. Obtain the hot exciter field resistance from the manufacturer’s data for your generator.
3. Calculate the Current Boost System field forcing voltage by multiplying the field current value
obtained in Step 1 by the resistance obtained in Step 2.
4. Position the Output Limit Select jumpers for the voltage range that most closely matches the field
forcing voltage calculated in Step 3. Jumper positions are summarized in the following
paragraphs.
•
60 Vdc Output Limit: jumper terminals TB2-7 to 5 and jumper terminals TB2-8 to 6.
•
120 Vdc Output Limit: jumper terminals TB2-7 to 3 and jumper terminals TB2-8 to 4.
•
220 Vdc Output Limit: jumper terminals TB2-7 to 1 and jumper terminals TB2-8 to 2.
Output Limit Adjustment
Set the output voltage limit of the CBS 212A. The Output Limit Adjustment control has an adjustment
range of 50 to 100 percent of the voltage selected by the Output Limit Selection jumpers.
A coarse adjustment of the CBS 212A output voltage limit can be made by approximation. The following
example illustrates the technique.
•
If the desired voltage limit is 90 Vdc and the Output Limit Selection jumpers are in the 120 Vdc
position, set the Output Limit Adjustment control to the midpoint (halfway between 50 percent and
100 percent).
If a more precise setting of the output limit is desired, the adjustment must be performed during short-
circuit testing of the generator. Refer to the generator manufacturer’s recommended procedures for short-
circuit testing and perform the following steps.
1. Rotate the Output Limit Adjustment control fully counterclockwise.
2. Connect a dc voltmeter to terminals TB1-P (+) and N (–).
3. Apply a three-phase short-circuit to the generator output in accordance with the generator
manufacturer’s procedures.
4. While observing the voltmeter, slowly rotate the Output Limit Adjustment control clockwise until
the desired output voltage at terminals TB1-P and N is obtained.
CBS 212A Installation