Completing In-Field Recalibrations

This is intended to provide information on how to recalibrate zeros the output current, output voltage, input current, and input voltage. 

Note:
In-field recalibrations should be completed only upon necessity. Changing the calibration values may result in hazardous conditions within the field circuit or damage to equipment.

How to Determine if Recalibration is Needed 

If you suspect that the CCR measurements are not accurately reflecting the actual conditions of CCR input or output, complete the following steps:

To Verify Output Current  

• Using a True RMS clamp meter, clamp on one leg of the output circuit wire. 
• Put the CCR into Local mode and turn it on to the first brightness step. 
• Check the DMM-measured value against the CCR-measured value. Due to a difference in the fidelity of measuring in the different equipment, you may see a slight difference.
• Log the measured numbers. 
• Put the CCR on the highest brightness step. Log the measured numbers. 
• If the numbers are consistently more than .5 amps different, you may want to consider recalibration. 

To Verify Output Voltage 

• Put the CCR into Local mode and turn the output power off. 
• Open the CCR door and pull the door switch plunger toward you laterally to bypass the safety interlock. 
• Turn the CCR on to any brightness step. 
• Using voltage probes on a known, calibrated DMM, measure the AC voltage across V1 and V2 on the 11-pin firing card terminal block by probing the screw heads. Multiply the measured voltage by the “V1-V2 Output Voltage Measurement Factor” provided on the CCR Datasheet at the end of this manual. If the factor is not available, contact Airport Lighting Company. 
• If the calculated voltage is not within 5% of the CCR-displayed output voltage, you may want to consider recalibration. 

To Verify Input Current

• Perform this only with an Input CT. 
• Using a True RMS clamp meter,  place the clamp on the input circuit wire.
• Put the CCR into Local mode and turn it on to the first brightness step. 
• Check the DMM-measured value against the CCR-measured value. Due to a difference in the fidelity of measuring in the different equipment, you may see a slight difference.
• Log the measured numbers. 
• Put the CCR on the highest brightness step. Log the measured numbers. 
• If the numbers are consistently more than .5 amps different, you may want to consider recalibration.

To Verify Input Voltage

• Put the CCR into Local mode and turn the output power off.
• Open the CCR door and pull the door switch plunger toward you laterally to bypass the safety interlock.
• Turn the CCR on to any brightness step.
•  Using voltage probes on a known, calibrated DMM, measure the input voltage. It may be measured at the contactor, at the power-side fuse block, or on the control transformer.
• Log the measured numbers.
• Put the CCR on the highest brightness step.
• Log the measured numbers.
• If the numbers are consistently more than 5% different, you may want to consider recalibration.

Calibrate Zeros - This step must be completed prior to other calibration steps

This command will have the CCR find a zero threshold in the input AC voltage. It is required when making equipment changes to the CCR, or when a part is replaced. Before completing this calibration: put the CCR in Local Mode and turn the output off.

Configuration Menu > CCR Config > Calibrate > Zeros > [Execute]

Note: A resistor load bank, such as can be provided by Airport Lighting Company, is recommended to provide a purely resistive load to the CCR during calibration. Ideally, the CCR should be loaded at 100% of its kW rating for the most accurate calibration.

Calibrating Output Current

Once the Calibrate Zeros is done, check to see if the reading discrepancy still exists. If it does, continue. 

• Connect a known, calibrated current clamp to a known, calibrated digital multimeter (DMM) and place the clamp on the output circuit wire.
• Connect a load bank to the CCR. • Put the CCR into Local mode.
• Navigate to the following menu, but do not enter the “Output Current” screen yet:

  Configuration Menu > CCR Config > Calibrate > Output Current

• The LOCAL UP and LOCAL DOWN arrows will still operate while in the menu, allowing for easier calibration.  Put the CCR on the lowest brightness step.
• Once the CCR is on the lowest brightness step, push the left DOT button to enter the “Output Current” screen.
• Check the DMM-measured current value. Use the UP and DOWN arrows below the screen to adjust the calibration value. Once the values match, push the left DOT button to accept.
• Put the CCR on the highest brightness step, while staying in the calibration menu.
• Check the DMM-measured current value. Use the UP and DOWN arrows below the screen to adjust the calibration value. Once the values match, push the left DOT button to accept.
• Cycle through the brightness steps, and verify the new calibration with the DMM. If the calibration is now acceptable, push the right DOT button until you’re asked to Record Changes, to which you need to execute Yes.
• If the calibration needs additional fine-tuning, complete the calibration procedure again.

If the calibration procedure does not yield acceptable results, you may want to restore a known good calibration. Refer to Restoring a Known Good Setting for more information.

Calibrating Output Voltage

• Connect a load bank to the CCR.
• Put the CCR into Local mode.
• Open the CCR door and pull the door switch plunger toward you laterally to bypass the safety interlock.
• Locate the V1 and V2 wires that connect to the firing card through an 11-position green, removable terminal block. This calibration requires measuring AC voltage across those two screwheads while the CCR is on, while the terminal block is plugged in.
• Navigate to the following menu, but do not enter the “Output Voltage” screen yet:

  Configuration Menu > CCR Config > Calibrate > Output Voltage 

• The LOCAL UP and LOCAL DOWN arrows will still operate while in the menu, allowing for easier calibration. Put the CCR on the lowest brightness step.
• Once the CCR is on the lowest brightness step, push the left DOT button to enter the “Output Voltage” screen.
• Using voltage probes on a known, calibrated DMM, measure the AC voltage across V1 and V2 on the 11pin firing card terminal block. Multiply the measured voltage by the “V1-V2 Output Voltage Measurement Factor”. If the factor is not available, contact Airport Lighting Company.
• Use the UP and DOWN arrows below the screen to adjust the calibration value to the calculated value. Once the values match, push the left DOT button to accept.
• Put the CCR on the highest brightness step, while staying in the calibration menu. • Once again, multiply the DMM-measured voltage by the V1-V2 Output Voltage Measurement Factor. Use the UP and DOWN arrows below the screen to adjust the calculated value. Once the values match, push the left DOT button to accept.
• Cycle through the brightness steps, and verify the new calibration. If the calibration is now acceptable, push the right DOT button until you’re asked to Record Changes, to which you need to execute Yes.
• If the calibration needs additional fine-tuning, complete the calibration procedure again.

If the calibration procedure does not yield acceptable results, you may want to restore a known good calibration. Refer to Restoring a Known Good Setting for more information.

Calibrating Input Current

Note: This calibration may be completed only if the CCR has an input CT installed.

• Connect a known, calibrated current clamp to a known, calibrated digital multimeter (DMM) and place the clamp on an input feed wire.
• Connect a load bank to the CCR. 
• Put the CCR into Local mode.
• Navigate to the following menu, but do not enter the “Input Current” screen yet:

Configuration Menu > CCR Config > Calibrate > Input Current

• The LOCAL Up and LOCAL Down arrows will still operate while in the menu, allowing for easier calibration. Put the CCR on the lowest brightness step.
• Once the CCR is on the lowest brightness step, push the left DOT button to enter the “Input Current” screen.
• Check the DMM-measured current value. Use the UP and DOWN arrows below the screen to adjust the calibration value. Once the values match, push the left DOT button to accept.
• Put the CCR on the highest brightness step, while staying in the calibration menu.
• Check the DMM-measured current value. Use the UP and DOWN arrows below the screen to adjust the calibration value. Once the values match, push the left DOT button to accept.
• Cycle through the brightness steps, and verify the new calibration with the DMM. If the calibration is now acceptable, push the right DOT button until you’re asked to Record Changes, to which you need to execute Yes.
• If the calibration needs additional fine-tuning, complete the calibration procedure again.

If the calibration procedure does not yield acceptable results, you may want to restore a known good calibration. Refer to Restoring a Known Good Setting for more information.

Calibrating Input Voltage

• Connect a load bank to the CCR.
• Put the CCR into Local mode.
• Open the CCR door and pull the door switch plunger toward you laterally to bypass the safety interlock.
• Navigate to the following menu, but do not enter the “Input Voltage” screen yet:

  Configuration Menu > CCR Config > Calibrate > Input Voltage

• The LOCAL Up and LOCAL Down arrows will still operate while in the menu, allowing for easier calibration. Put the CCR on the lowest brightness step.
• Once the CCR is on the lowest brightness step, push the left DOT button to enter the “Input Voltage” screen.
• Using voltage probes on a known, calibrated DMM, measure the input voltage. It may be measured at the contactor, at the power-side fuse block, or on the control transformer.
• Check the DMM-measured value. Use the UP and DOWN arrows below the screen to adjust the calibration value. Once the values match, push the left DOT button to accept.
• Put the CCR on the highest brightness step, while staying in the calibration menu.
• Check the DMM-measured value. Use the UP and DOWN arrows below the screen to adjust the calibration value. Once the values match, push the left DOT button to accept.
• Cycle through the brightness steps, and verify the new calibration with the DMM. If the calibration is now acceptable, push the right DOT button until you’re asked to Record Changes, to which you need to execute Yes.
• If the calibration needs additional fine-tuning, complete the calibration procedure again.

If the calibration procedure does not yield acceptable results, you may want to restore a known good calibration. Refer to Restoring a Known Good Setting for more information.

 

Airport Lighting Company | Type L-828, Type L-829 Ferroresonant Constant Current Regulator