Circuit Breakers Testing

Low Voltage, Less than 600V

Circuit breakers testing is essential for safety, reliability, compliance with regulations, and the overall efficiency of electrical systems. Regular testing helps identify issues early, prevent accidents, and extend the lifespan of electrical equipment. Circuit breakers should be tested regularly for several important reasons:

Circuit breakers should be tested regularly for several important reasons:

Safety:
The primary reason for testing circuit breakers is to ensure the safety of people and property. Circuit breakers are designed to protect against electrical faults, such as overloads and short circuits. If a circuit breaker fails to operate when needed, it can lead to electrical fires, damage to equipment, and potentially life-threatening situations.

Reliability:
Regular testing helps verify the reliability of circuit breakers. These devices are meant to operate when required, and their failure can disrupt operations and cause downtime in industrial and commercial settings. Testing ensures that circuit breakers will function as intended when needed.

Thermal-Magnetic Circuit Breaker

Compliance:
In many jurisdictions, electrical codes and regulations require periodic testing and maintenance of circuit breakers and other electrical equipment. Compliance with these regulations is essential to avoid legal and liability issues.

Preventive Maintenance:
Testing circuit breakers is part of a comprehensive preventive maintenance program for electrical systems. Identifying and addressing issues early can prevent costly repairs and downtime in the long run. Routine testing can catch problems before they escalate into major issues.

Circuit Breaker Test Procedures, Low Voltage (less than 600V)

Circuit Breaker Performance Tests

Manufactures recommend the following visual, mechanical, and electrical tests to verify a circuit breaker's serviceability

Visual and Mechanical Inspection
  1. Clean allexternal contamination to permit internal heat dissipation.
  2. Inspect all surfaces for cracks or damage .
  3. Check for loose connections, and tighten circuit breaker terminals and bus bar connections. Use the manufacturer’s recommended torque values.
  4. Manually exercise the mechanismby switching the breaker on and off.
  5. Check for high-humidity conditions since high humidity will deteriorate the insulation system.
  6. Check for hot spots typically caused by overheating due to termination or connections being loose, high contact resistance, or inadequate ventilation.
Primary Current Test Set

Performing primary current injection testing is essential for verifying the condition and calibration of a circuit breaker's protective elements. Primary injection testing involves injecting pulses of current (pulse duration between 5 and 10 cycles) with steadily incrementing magnitudes of current through a circuit breaker’s poles.

This test verifies the breaker's thermal magnetic or solid-state trip unit operates properly by simulating a fault, thus verifying the breakers protection elements set points..

Simulating a fault is performed by connecting the test set to the line and load side terminals of the breaker. Current is then injected through the breaker. The current is raised until it reaches the pick-up set points of the protective element under test, causing the breaker to trip (open).

High Current Test Set
Insulation Resistance

Severe environmental conditions, such as high humidity, can reduce the dielectric strength of molded case circuit breakers. Insulation resistance should be tested during acceptance and maintenance testing.

Contact Resistance

This test consists of applying a DC across the closed circuit breaker contacts and measuring resistance across the contact. An excessive resistance value could indicate abnormal conditions such as contact and/or connection erosion and contamination.

A circuit breaker's Stationary and moving contacts need to inspected and tested. Although Contacts are designed to endure the stresses of electrical arcing, they require regular inspection and maintenance. Measuring the resistance of a breaker's contact at the micro- or milli-ohm level can verify that electrical connections are made properly, and can detect the following problems:

  • Loose connections
  • Adequate tension on bolted joints
  • Eroded contact surfaces
  • Contaminated or corroded contacts
Test Procedure
Visual and Mechanical Inspection:
  1. Compare equipment nameplate data with drawings and specifications.
  2. Inspect physical and mechanical condition.
  3. Inspect anchorage and alignment.
  4. Verify the unit is clean.
  5. Operate the circuit breaker to insure smooth operation.
  6. Inspect operating mechanism, contacts, and arc chutes in unsealed units.
  7. Perform adjustments for final protective device settings in accordance with the coordination study.
Insulation Test:
  1. Perform insulation-resistance tests on each pole, phase-to-phase and phase-to-ground with the circuit breaker closed, and across each open pole.
    1. Phase conductor to adjacent Phase conductor
      (A-ph & B-ph, B-ph & C-ph, C-ph & A-ph)
    2. Phase to Ground Bus
      (A-ph & ground, B-ph & ground, C-ph & ground)
    3. Line-side Phase to Load-side Phase
      (A-ph & neutral, B-ph & neutral, C-ph & neutral)
  2. Test voltage shall be applied to each conductor for one minute.
    3. Neta Table 100.1
    NETA Table 100.1 shows recommended minimum test result values
  3. Perform insulation-resistance tests on all control wiring with respect to ground. Applied potential shall be 500 volts dc for 300-volt rated cable and 1000 volts dc for 600-volt rated cable. Test duration shall be one minute. For units with solid-state components, follow manufacturer’s recommendation. (optional)
Contact Resistance Test:
  1. Perform a contact/pole-resistance test.
  2. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  3. Micro-ohm or dc milli-volt drop values shall not exceed the high levels of the normal range as indicated in the manufacturer’s published data. If manufacturer’s published data is not available, investigate values that deviate from adjacent poles or similar breakers by more than 50 percent of the lowest value.
Electrical Test Procedure
  1. Determine long-time pickup and delay by primary current injection.
    Long-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current characteristic tolerance band, including adjustment factors. If manufacturer’s curves are not available, trip times shall not exceed the value shown in Table 100.7.
  2. Determine short-time pickup and delay by primary current injection.
    Short-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  3. Determine instantaneous pickup by primary current injection.
    Instantaneous pickup values shall be as specified and within manufacturer’s published tolerances. In the absence of manufacturer’s published data, refer to Table 100.8.
  4. Determine ground-fault pickup and time delay by primary current injection.
    Ground fault pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  5. Perform minimum pickup voltage tests on shunt trip and close coils in accordance with manufacturer’s published data.
    Pickup values and trip characteristics shall be within manufacturer’s published tolerances. Minimum pickup voltage of the shunt trip and close coils shall conform to the manufacturer’s published data. In the absence of the manufacturer’s published data, refer to Table 100.20.
  6. Verify correct operation of auxiliary features such as trip and pickup indicators, zone interlocking, electrical close and trip operation, trip-free, anti-pump function, and trip unit battery condition. Reset all trip logs and indicators.
    Breaker open, close, trip, trip-free, anti-pump, and auxiliary features shall function as designed.
  7. Verify operation of charging mechanism.
    The charging mechanism shall operate in accordance with manufacturer’s published data.

Secondary Injection Test

  • Can be done on electronic breakers only
  • Tests the trip unit only
  • Test kit is small and portable
  • Quick, Easier, and less expensive to perform than primary injection and

Solid-state trip units can be tested via secondary current injection using a test set specifically designed for the device to be tested. The main shortcoming of the secondary current injection test method is that only the solid-state trip unit logic and components are tested.

Unlike primary injection, this test method does not verify the current sensors, wiring, or circuit breaker current carrying components. This is the main reason why the primary injection test method has superiority over secondary injection testing.

No Trip Test

The protective functions of the electronic trip device can be tested, but the trip device won't send a trip signal to the circuit breakers trip actuator. This test can be performed while the circuit breaker is energized and carrying load current because a no-trip test won't cause the circuit breaker to open.

Trip Test

The protective functions of the electronic circuit are tested just like a no-trip mode test, except the trip unit will send a signal to the circuit breakers trip actuator. This will cause the circuit breaker to open, which is why this test is typically performed only when a circuit breaker is withdrawn from its compartment and therefore disconnected from the switchgear bus

Neta Table 100.1
NETA Test Procedure

NETA ATS

7.6.1.1 Circuit Breakers, Air, Insulated-Case/Molded-Case

A. Visual and Mechanical Inspection:
  1. Compare equipment nameplate data with drawings and specifications.
  2. Inspect physical and mechanical condition.
  3. Inspect anchorage and alignment.
  4. Verify the unit is clean.
  5. Operate the circuit breaker to insure smooth operation.
  6. Inspect bolted electrical connections for high resistance using one or more of the following methods:
    1. Use of a low-resistance ohmmeter in accordance with Section 7.6.1.1.B.1.
    2. Verify tightness of accessible bolted electrical connections by calibrated torquewrench method in accordance with manufacturer’s published data or Table 100.12.
    3. Perform thermographic survey in accordance with Section 9. (optional)
  7. Inspect operating mechanism, contacts, and arc chutes in unsealed units.
  8. Perform adjustments for final protective device settings in accordance with the coordination study.
B. Electrical Tests:
  1. Perform resistance measurements through bolted connections with a low-resistance ohm meter, if applicable, in accordance with Section 7.6.1.1.A.6.1.
  2. Perform insulation-resistance tests for one minute on each pole, phase-to-phase and phase-toground with the circuit breaker closed, and across each open pole. Apply voltage in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1.
  3. Perform a contact/pole-resistance test.
  4. Perform insulation-resistance tests on all control wiring with respect to ground. Applied potential shall be 500 volts dc for 300-volt rated cable and 1000 volts dc for 600-volt rated cable. Test duration shall be one minute. For units with solid-state components, follow manufacturer’s recommendation. (optional)
  5. Determine long-time pickup and delay by primary current injection.
  6. Determine short-time pickup and delay by primary current injection.
  7. Determine ground-fault pickup and time delay by primary current injection.
  8. Determine instantaneous pickup by primary current injection.
  9. Test functions of the trip unit by means of secondary injection. (optional)
  10. Perform minimum pickup voltage tests on shunt trip and close coils in accordance with manufacturer’s published data.
  11. Verify correct operation of auxiliary features such as trip and pickup indicators, zone interlocking, electrical close and trip operation, trip-free, anti-pump function, and trip unit battery condition. Reset all trip logs and indicators.
  12. Verify operation of charging mechanism.
C. Test Values – Visual and Mechanical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Bolt-torque levels shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.12.
  3. Results of the thermographic survey shall be in accordance with Section 9. (optional)
  4. Settings shall comply with coordination study recommendations.
D. Test Values – Electrical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Insulation-resistance values shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1. Values of insulation resistance less than this table or manufacturer’s recommendations should be investigated.
  3. Micro-ohm or dc mill-ivolt drop values shall not exceed the high levels of the normal range as indicated in the manufacturer’s published data. If manufacturer’s published data is not available, investigate values that deviate from adjacent poles or similar breakers by more than 50 percent of the lowest value.
  4. Insulation-resistance values of control wiring shall not be less than two megohms.
  5. Long-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current characteristic tolerance band, including adjustment factors. If manufacturer’s curves are not available, trip times shall not exceed the value shown in Table 100.7.
  6. Short-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  7. Ground fault pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  8. Instantaneous pickup values shall be as specified and within manufacturer’s published tolerances. In the absence of manufacturer’s published data, refer to Table 100.8.
  9. Pickup values and trip characteristics shall be within manufacturer’s published tolerances.
  10. Minimum pickup voltage of the shunt trip and close coils shall conform to the manufacturer’s published data. In the absence of the manufacturer’s published data, refer to Table 100.20.
  11. Breaker open, close, trip, trip-free, anti-pump, and auxiliary features shall function as designed.
  12. The charging mechanism shall operate in accordance with manufacturer’s published data.

NETA ATS

7.6.1.2 Circuit Breakers, Low-Voltage Power

A. Visual and Mechanical Inspection:
  1. Compare equipment nameplate data with drawings and specifications.
  2. Inspect physical and mechanical condition.
  3. Inspect anchorage, alignment, and grounding.
  4. Verify that all maintenance devices are available for servicing and operating the breaker.
  5. Verify the unit is clea
  6. Verify the arc chutes are intact.
  7. Inspect moving and stationary contacts for condition and alignment.
  8. Verify that primary and secondary contact wipe and other dimensions vital to satisfactory operation of the breaker are correct.
  9. Perform all mechanical operator and contact alignment tests on both the breaker and its operating mechanism in accordance with manufacturer’s published data.
  10. Inspect bolted electrical connections for high resistance using one or more of the following methods:
    1. Use of a low-resistance ohmmeter in accordance with Section 7.6.1.2.B.1.
    2. Verify tightness of accessible bolted electrical connections by calibrated torquewrench method in accordance with manufacturer’s published data or Table 100.12.
    3. Perform a thermographic survey in accordance with Section 9. (optional)
  11. Verify cell fit and element alignment.
  12. Verify racking mechanism operation.
  13. Verify appropriate lubrication on moving current-carrying parts and on moving and sliding surfaces.
  14. Perform adjustments for final protective device settings in accordance with coordination study provided by end user.
  15. Record as-found and as-left operation counter readings.
B. Electrical Tests:
  1. Perform resistance measurements through bolted connections with a low-resistance ohmmeter, if applicable, in accordance with Section 7.6.1.2.A.10.1.
  2. Perform insulation-resistance tests for one minute on each pole, phase-to-phase and phase-toground with the circuit breaker closed, and across each open pole. Test voltage shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1.
  3. Perform a contact/pole-resistance test.
  4. Perform insulation-resistance tests on all control wiring with respect to ground. Applied potential shall be 500 volts dc for 300-volt rated cable and 1000 volts dc for 600-volt rated cable. Test duration shall be one minute. For units with solid-state components, follow manufacturer’s recommendation.
  5. Determine long-time pickup and delay by primary current injection.
  6. Determine short-time pickup and delay by primary current injection.
  7. Determine ground-fault pickup and delay by primary current injection.
  8. Determine instantaneous pickup value by primary current injection.
  9. Test functions of the trip unit by means of secondary injection. (optional)
  10. Perform minimum pickup voltage tests on shunt trip and close coils in accordance with manufacturer’s published data.
  11. Verify correct operation of any auxiliary features such as trip and pickup indicators, zone interlocking, electrical close and trip operation, trip-free, antipump function, and trip unit battery condition. Reset all trip logs and indicators.
  12. Verify operation of charging mechanism.
C. Test Values – Visual and Mechanical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Bolt-torque levels shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.12.
  3. Results of the thermographic survey shall be in accordance with Section 9. (optional)
  4. Settings shall comply with coordination study recommendations.
  5. Operations counter shall advance one digit per close-open cycle.
D. Test Values – Electrical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Insulation-resistance values of circuit breakers shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1. Values of insulation resistance less than this table or manufacturer’s recommendations should be investigated.
  3. Micro-ohm or dc milli-volt drop values shall not exceed the high levels of the normal range as indicated in the manufacturer’s published data. In the absence of manufacturer’s published data, investigate values that deviate from adjacent poles or similar breakers by more than 50 percent of the lowest value
  4. Insulation-resistance values of control wiring shall not be less than two megohms.
  5. Long-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current characteristic tolerance band, including adjustment factors. If manufacturer’s curves are not available, trip times shall not exceed the value shown in Table 100.7.
  6. Short-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  7. Ground fault pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  8. Instantaneous pickup values shall be as specified and within manufacturer’s published tolerances. In the absence of manufacturer’s published data, refer to Table 100.8.
  9. Pickup values and trip characteristic shall be as specified and within manufacturer’s published tolerances.
  10. Minimum pickup voltage of the shunt trip and close coils shall conform to the manufacturer’s published data. In the absence of the manufacturer’s published data, refer to Table 100.20.
  11. Auxiliary features shall operate in accordance with manufacturer’s published data.
  12. The charging mechanism shall operate in accordance with manufacturer’s published data.

NETA MTS

7.6.1.1 Circuit Breakers, Air, Insulated-Case/Molded-Case

A. Visual and Mechanical Inspection:
  1. Inspect physical and mechanical condition.
  2. Inspect anchorage and alignment.
  3. Prior to cleaning the unit, perform as-found tests, if required.
  4. Clean the unit.
  5. Operate the circuit breaker to ensure smooth operation.
  6. Inspect bolted electrical connections for high resistance using one or more of the following methods:
    1. Use of a low-resistance ohmmeter in accordance with Section 7.6.1.1.B.1.
    2. Verify tightness of accessible bolted electrical connections by calibrated torque wrench method in accordance with manufacturer’s published data or Table 100.12.
    3. Perform thermographic survey in accordance with Section 9. (optional)
  7. Inspect operating mechanism, contacts, and arc chutes in unsealed units.
  8. Perform adjustments for final protective device settings in accordance with coordination study provided by end user.
  9. Perform as-left tests.
B. Electrical Tests:
  1. Perform resistance measurements through bolted connections with a low-resistance ohm meter in accordance with Section 7.6.1.1.A.6.1.
  2. Perform insulation-resistance tests for one minute on each pole, phase-to-phase and phaseto- ground with the circuit breaker closed, and across each open pole. Apply voltage in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1.
  3. Perform a contact/pole-resistance test.
  4. Perform insulation-resistance tests on all control wiring with respect to ground. The applied potential shall be 500 volts dc for 300-volt rated cable and 1000 volts dc for 600-volt rated cable. Test duration shall be one minute. For units with solid-state components, follow manufacturer’s recommendation. (optional)
  5. Determine long-time pickup and delay by primary current injection.
  6. Determine short-time pickup and delay by primary current injection.
  7. Determine ground-fault pickup and time delay by primary current injection.
  8. Determine instantaneous pickup by primary current injection.
  9. Test functions of the trip unit by means of secondary injection. (optional)
  10. Perform minimum pickup voltage test on shunt trip and close coils in accordance with Table 100.20.
  11. Verify correct operation of auxiliary features such as trip and pickup indicators, zone interlocking, electrical close and trip operation, trip-free, anti-pump function, and trip unit battery condition. Reset all trip logs and indicators.
  12. Reset all trip logs and indicators.
  13. Verify operation of charging mechanism.
C. Test Values – Visual and Mechanical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Bolt-torque levels should be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.12.
  3. Results of the thermographic survey shall be in accordance with Section 9. (optional)
  4. Settings shall comply with coordination study recommendations.
D. Test Values – Electrical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Insulation-resistance values should be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1. Values of insulation resistance less than this table or manufacturer’s recommendations should be investigated.
  3. Micro-ohm or dc milli-volt drop values should not exceed the high levels of the normal range as indicated in the manufacturer’s published data. If manufacturer’s data is not available, investigate values that deviate from adjacent poles or similar breakers by more than 50 percent of the lowest value.
  4. Insulation-resistance values of control wiring should be comparable to previously obtained results but not less than two mega-ohms.
  5. Long-time pickup values should be as specified, and the trip characteristic should not exceed manufacturer’s published time-current characteristic tolerance band, including adjustment factors. If manufacture
  6. Short-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  7. Ground fault pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  8. Instantaneous pickup values shall be as specified and within manufacturer’s published tolerances. In the absence of manufacturer’s published data, refer to Table 100.8.
  9. Pickup values and trip characteristics shall be within manufacturer’s published tolerances.
  10. Minimum pickup voltage of the shunt trip and close coils shall conform to the manufacturer’s published data. In the absence of the manufacturer’s published data, refer to Table 100.20.
  11. Breaker open, close, trip, trip-free, anti-pump, and auxiliary features shall function as designed.
  12. Trip logs and indicators are reset.
  13. The charging mechanism shall operate in accordance with manufacturer’s published data.

NETA ATS

7.6.1.2 Circuit Breakers, Low-Voltage Power

A. Visual and Mechanical Inspection:
  1. Inspect physical and mechanical condition.
  2. Inspect anchorage, alignment, and grounding.
  3. Verify that all maintenance devices are available for servicing and operating the breaker.
  4. Prior to cleaning the unit, perform as-found tests, if required.
  5. Clean the unit.
  6. Inspect arc chutes.
  7. Inspect moving and stationary contacts for condition and alignment.
  8. Verify that primary and secondary contact wipe and other dimensions vital to satisfactory operation of the breaker are in accordance with manufacturer’s published data.
  9. Perform all mechanical operator and contact alignment tests on both the breaker and its operating mechanism in accordance with manufacturer’s published data.
  10. Inspect bolted electrical connections for high resistance using one or more of the following methods:
    1. Use of a low-resistance ohmmeter in accordance with Section 7.6.1.2.B.1.
    2. Verify tightness of accessible bolted electrical connections by calibrated torque wrench method in accordance with manufacturer’s published data or Table 100.12.
    3. Perform a thermographic survey in accordance with Section 9. (optional)
  11. Verify cell fit and element alignment.
  12. Verify racking mechanism operation.
  13. Verify appropriate lubrication on moving current-carrying parts and on moving and sliding surfaces.
  14. Perform adjustments for final protective device settings in accordance with coordination study provided by end user.
  15. Perform as-left tests.
  16. Record as-found and as-left operation counter readings.
B. Electrical Tests:
  1. Perform resistance measurements through bolted connections with a low-resistance ohmmeter, if applicable, in accordance with Section 7.6.1.2.A.10.1.
  2. Perform insulation-resistance tests for one minute on each pole, phase-to-phase and phase-toground with the circuit breaker closed, and across each open pole. Test voltage shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1.
  3. Perform a contact/pole-resistance test.
  4. Perform insulation-resistance tests on all control wiring with respect to ground. Applied potential shall be 500 volts dc for 300-volt rated cable and 1000 volts dc for 600-volt rated cable. Test duration shall be one minute. For units with solid-state components, follow manufacturer’s recommendation.
  5. Determine long-time pickup and delay by primary current injection.
  6. Determine short-time pickup and delay by primary current injection.
  7. Determine ground-fault pickup and delay by primary current injection.
  8. Determine instantaneous pickup value by primary current injection.
  9. Test functions of the trip unit by means of secondary injection. (optional)
  10. Perform minimum pickup voltage test on shunt trip and close coils in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, refer to Table 100.20.
  11. Verify correct operation of auxiliary features such as trip and pickup indicators, zone interlocking, electrical close and trip operation, trip-free, antipump function, and trip unit battery condition.
  12. Reset all trip logs and indicators.
  13. Verify operation of charging mechanism.
C. Test Values – Visual and Mechanical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Bolt-torque levels shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.12.
  3. Results of the thermographic survey shall be in accordance with Section 9. (optional)
  4. Settings shall comply with coordination study recommendations.
  5. Operations counter shall advance one digit per close-open cycle.
D. Test Values – Electrical
  1. Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
  2. Insulation-resistance values of circuit breakers shall be in accordance with manufacturer’s published data. In the absence of manufacturer’s published data, use Table 100.1. Values of insulation resistance less than this table or manufacturer’s recommendations should be investigated.
  3. Micro-ohm or dc milli-volt drop values shall not exceed the high levels of the normal range as indicated in the manufacturer’s published data. In the absence of manufacturer’s published data, investigate values that deviate from adjacent poles or similar breakers by more than 50 percent of the lowest value
  4. Insulation-resistance values of control wiring shall not be less than two megohms.
  5. LLong-time pickup values should be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current characteristic tolerance band.
  6. Short-time pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  7. Ground fault pickup values shall be as specified, and the trip characteristic shall not exceed manufacturer’s published time-current tolerance band.
  8. Instantaneous pickup values should be within the tolerances of manufacturer’s published data.
  9. Pickup values and trip characteristic shall be as specified and within manufacturer’s published tolerances.
  10. Minimum pickup voltage of the shunt trip and close coils shall conform to the manufacturer’s published data. In the absence of the manufacturer’s published data, refer to Table 100.20.
  11. Auxiliary features shall operate in accordance with manufacturer’s published data.
  12. Trip logs and indicators are reset.
  13. The charging mechanism should operate in accordance with manufacturer’s published data.
NETA ATS / MTS
TABLE 100.1
Neta Table 100.5
NETA ATS / MTS
TABLE 100.7
Neta Table 100.7
NETA ATS / MTS
TABLE 100.8
Neta Table 100.5
NETA ATS / MTS
TABLE 100.12
Neta Table 100.5 Neta Table 100.5
NETA ATS / MTS
TABLE 100.20
Neta Table 100.1 Neta Table 100.5