Circuit-Breaker.ppt
10
Circuit Breaker Testing M.M. Meraat
description
cb
Transcript of Circuit-Breaker.ppt
Circuit Breaker Testing
M.M. Meraat
Classification of Testing
Type Test – Conducted on each prototype of CB.
Routine Test – Conducted on each CB. Reliability Test – Check the reliability in actual
operating condition. Commissioning Test – Conducted on CB after
installation.
Type Test
Mechanical Test Withstand voltage or Dielectric Test Temperature Rise Test Short Circuit Test
Type Test– Mechanical Test
Endurance Test – Circuit Breaker checked for 1000 open close operation.
Operating Limit Test – CB auxiliaries is tested.Lower value – CB perform properly without hesitationUpper Value – Energy input does not damage the auxiliary
equipment.
Component Testing – Special type of test done during early development or some other requirements.
Type Test – Dielectric Test
Lighting Impulse Test – 1.2/50 uSec test waveform.5 shots of +ve polarity.5 shots of –ve polarity.
Switching Impulse Test – 50/2500 uSec waveform.5 shots of +ve polarity.5 shots of –ve polarity.Above 300kv should be in wet condition.
Power frequency withstand Test – Total of 15 shots Not more than 2 flashovers.Test frequency 100hz.Normal current, normal voltage.
Type Test – Temperature rise test
Should me made on a new CB with clean contact parts.
Done in totally enclosed place. Control ckt. And auxiliaries are also undergo
through test. Reading of the various parts are taken at a
interval of 1 or half an hour. Max. temp. should not exceed the permissible
value.
Type Test – Temperature rise test
Item Max. Temp.Copper contact
in air with silver plating
in air without silver plating
in oil with silver plating
in oil without silver plating
105
75
90
80 In oil CB 80Terminals of CB with silver plating
without silver plating105
90
Metal parts in contact with class E insulation 100
Type Test – Short circuit Test
Breaking Test –Capacity of CB to open during a short circuit. The following factors are checked…….
1. Condition of CB before test2. Condition of CB during test3. Condition of CB after test4. Applied voltage before test5. TRV6. Test frequency
etc…..
Making Test – Capacity of CB to close during an existing fault. The same factors as above are checked during testing.
Type Test – Operating Sequence Test
According to IEC – O-3minutes-CO-3minutes-CO for non-auto reclosing CB.
O-.3Sec-CO-3minutes-CO-CO for auto reclosing CB.
Test Duty 1: 10% of rated SC current<20% DC component
Test Duty 2: 30% of rated SC current
<20% DC component
Test Duty 3: 60% of rated SC current
<20% DC component
Test Duty 4: 100% of rated SC current
<20% DC component
Test Duty 5: 100% of rated SC current(Only the symmetrical component).
Routine Test
No load mechanical operation test – to verify speed of travel, opening time, closing time.
Millivolt drop test – To measure the contact resistance.
