Issue:
EVS External Voltage Sensing was added to a breaker, but what is shown on the Micrologic Trip Unit screen is incorrect. Is something miswired?
The breaker has voltage sensing, but the value shown on the trip unit screen is not right. Is something wrong with the trip unit?
Product Line:
Molded Case Circuit Breakers
Resolution:
If external voltage sensing has been added to a breaker and the voltages on the trip unit screen are incorrect, check the following to resolve the problem:
(1) Power sign
With the trip unit in the breaker, use the trip unit screen to set the correct power sign (press the maintenance menu wrench button, select "Micrologic setup", then "Power sign")
(2) System type
With the trip unit in the breaker, use the trip unit screen to set the correct system type (press the maintenance menu wrench button, select "Metering setup", then "System type")
(3) EVS phase and neutral wire terminations
Wearing proper PPE, make sure the EVS voltage sensing phase and neutral wires are securely fastened to the correct system conductors, and that those conductors read the correct system voltage
(4) EVS voltage sensing plug
Verify that the white EVS voltage sensing plug is in the correct position
EVS External Voltage Sensing was added to a breaker, but what is shown on the Micrologic Trip Unit screen is incorrect. Is something miswired?
The breaker has voltage sensing, but the value shown on the trip unit screen is not right. Is something wrong with the trip unit?
Product Line:
Molded Case Circuit Breakers
Resolution:
If external voltage sensing has been added to a breaker and the voltages on the trip unit screen are incorrect, check the following to resolve the problem:
(1) Power sign
With the trip unit in the breaker, use the trip unit screen to set the correct power sign (press the maintenance menu wrench button, select "Micrologic setup", then "Power sign")
- If the breaker is being top fed, select P+
- If the breaker is being bottom fed, select P-
(2) System type
With the trip unit in the breaker, use the trip unit screen to set the correct system type (press the maintenance menu wrench button, select "Metering setup", then "System type")
- Select "3Φ 3W 3CT" if the incoming system voltage is 3p3w (system does not have a neutral)
- Select "3Φ 4W 3CT" if the incoming system voltage is 3p4w (system has a neutral), and breaker terminals T1T2 are not connected to a neutral CT
- Select "3Φ 4W 4CT" if the incoming system voltage is 3p4w (system has a neutral), and breaker terminals T1T2 are connected to a neutral CT
(3) EVS phase and neutral wire terminations
Wearing proper PPE, make sure the EVS voltage sensing phase and neutral wires are securely fastened to the correct system conductors, and that those conductors read the correct system voltage
(4) EVS voltage sensing plug
Verify that the white EVS voltage sensing plug is in the correct position
- Turn off power feeding the equipment, and remove the breaker cover and the trip unit
- Using the below pictures as reference, locate the white EVS voltage sensing plug on the trip unit base and make sure it is correctly positioned as shown (tabs in the 9 and 12 o'clock positions)
- If the white plug is in the incorrect position (tabs in the 12 and 3 o'clock positions), push the plug out of the holder and re-install it in the correct position
Released for:Schneider Electric USA
