0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
What meters are kept on HV side in SC test?
insulation tester (Megger) can used to checked the short circuit on HV side. HI POT tester is also a means to checked the shot circuit in HV cable.
Why is an open circuit test performed on the low voltage side of a single phase transformer?
You always need to apply rated voltage to the primary in open circuit test (oc test helps to find iron loss which depends on the voltage applied which remains constant)so with smaller voltage applied to the low voltage side rated voltage can be achieved in primary.Further,the ammeter ,voltmeter and wattmeter connected to the primary can be of lower rating.
Why is open ckt test conducted on lv side?
in the open circuit test, the high voltage winding is open circuited and the measurements are made on the low winding side i.e, the open circuit test is performed on the L.V side. This is because if the measurements are made on HV side then voltage applied must be large and the current would be unsuitably small, for which the high voltage sources may not be readily available and at the same time the instrument ranges required should be very high, Also the result obtained may not be accurate. NOTE: iron loss will be same, if measured from either of the winding. in short circuit test. the low voltage winding is short circuited and the measurements are made on the high voltage winding side i,e,. the sort circuit test is performed on H.V side. This is because if the test is performed on the L.V side, the current will be suitably large for which the instruments used should be of very high ranges. moreover instruments of such high ranges and the auto-transformer capable of handling such high currents may not be readily available.
Why short circuit is performed on high voltage side?
This is because of two reasons: 1. Primarily because SC test is performed at rated Current(as we calculate series parameters-leakage impedance-in SC test). As the rated current on hv side is much less than lv side(VI = constant), so the rated hv side current is easily achieved(compared to lv side). Vice-versa is true for Open circuit test. 2. Also because we cannot short-circuit hv side, as, if we short-circuit hv side, V of hv side essentially falls to zero and since VI(KVA power)=constant, so the hv current will be very high(compared to low rated current on hv side), and will burn the winding. When short-circuiting lv side, the current also increases but this increase does not burn winding due to low rated V and high rated I (You can consider the example of 220/11V)on lv side. So,SC test is performed on hv side while shorting the lv side. Also SC test can be performed on either sides for small transformer rating. The above care must be taken for big transformer(High KVA rating)..
Why oc test done in lv side?
In OC test , the equipments are connected in LV side since we need to get rated voltage . if it is cinnected in HV side the value of voltage will be less and current wil be more.Hence the ordinary instruments cannot measure this value of current
What meters are kept on HV side in SC test?
insulation tester (Megger) can used to checked the short circuit on HV side. HI POT tester is also a means to checked the shot circuit in HV cable.
Why is an open circuit test performed on the low voltage side of a single phase transformer?
You always need to apply rated voltage to the primary in open circuit test (oc test helps to find iron loss which depends on the voltage applied which remains constant)so with smaller voltage applied to the low voltage side rated voltage can be achieved in primary.Further,the ammeter ,voltmeter and wattmeter connected to the primary can be of lower rating.
How do you carry short circuit test on power transformer?
For carrying Short Circuit Test on Power Transformer Do the following: 1] Isolate the Power Transformer from service. 2] Remove HV/LV Jumps and Disconnect Neutral from Earth/Ground. 3] Short LV Phases by Cu/Al plate which could withstand short circuit current and connect these short circuited terminals to Neutral 4] Energise HV side by LV supply (440 3ph Supply) with OLTC tap position on Normal. 5] Measure Current in Neutral, LV line voltages, HV Volatage and HV Line Currents on various OLTC Tap position. Analysis: If Neutral current is near to zero transformer windings are OK If Neutral current is higher or equal to Line current between LV Phase one of the winding is Open.
How do you carry out short circuit test on power transformers?
For carrying Short Circuit Test on Power Transformer Do the following: 1] Isolate the Power Transformer from service. 2] Remove HV/LV Jumps and Disconnect Neutral from Earth/Ground. 3] Short LV Phases by Cu/Al plate which could withstand short circuit current and connect these short circuited terminals to Neutral 4] Energise HV side by LV supply (440 3ph Supply) with OLTC tap position on Normal. 5] Measure Current in Neutral, LV line voltages, HV Volatage and HV Line Currents on various OLTC Tap position. Analysis: If Neutral current is near to zero transformer windings are OK If Neutral current is higher or equal to Line current between LV Phase one of the winding is Open.
Why rated voltage is to be applied to primary for open circuit test?
Open circuit test on a transformer is usually performed to measure the IRON losses.Iron losses are produced due to eddy current and hysteresis losses. In open circuit test, the LV side, generaly the secondary winding, is kept open and the HV side, generaly the primary winding is fed with the rated voltage and frequency. The rated voltage is applied in order to setup normal flux in the transformer, which in return further produces the normal iron losses at rated voltage. the wattmeter connected at the primary side will show the power consumed due to iron losses. this calculation further utilized for determing the efficiency of transformer.
Why open circuit test is performed on low voltage side?
generally open circuit test is performed on the low voltage side.....not on high voltage side.... becuase on low voltage side, we can apply that low voltage very easily ( i.e with a less amount of source is required)... whereas on high voltage side, we need a large power source in order to apply full voltage... in short circuit test, we will test on high voltage side by keeping Low voltage side being short circuit.because high voltage side needs less current source than low voltage side....
Why is open ckt test conducted on lv side?
in the open circuit test, the high voltage winding is open circuited and the measurements are made on the low winding side i.e, the open circuit test is performed on the L.V side. This is because if the measurements are made on HV side then voltage applied must be large and the current would be unsuitably small, for which the high voltage sources may not be readily available and at the same time the instrument ranges required should be very high, Also the result obtained may not be accurate. NOTE: iron loss will be same, if measured from either of the winding. in short circuit test. the low voltage winding is short circuited and the measurements are made on the high voltage winding side i,e,. the sort circuit test is performed on H.V side. This is because if the test is performed on the L.V side, the current will be suitably large for which the instruments used should be of very high ranges. moreover instruments of such high ranges and the auto-transformer capable of handling such high currents may not be readily available.
Why short circuit is performed on high voltage side?
This is because of two reasons: 1. Primarily because SC test is performed at rated Current(as we calculate series parameters-leakage impedance-in SC test). As the rated current on hv side is much less than lv side(VI = constant), so the rated hv side current is easily achieved(compared to lv side). Vice-versa is true for Open circuit test. 2. Also because we cannot short-circuit hv side, as, if we short-circuit hv side, V of hv side essentially falls to zero and since VI(KVA power)=constant, so the hv current will be very high(compared to low rated current on hv side), and will burn the winding. When short-circuiting lv side, the current also increases but this increase does not burn winding due to low rated V and high rated I (You can consider the example of 220/11V)on lv side. So,SC test is performed on hv side while shorting the lv side. Also SC test can be performed on either sides for small transformer rating. The above care must be taken for big transformer(High KVA rating)..
What is purpose of ten delta test on transformer?
To ascertain the life of insulation, or effectiveness of the insulation (HV to LV, HV to earth and LV to earth) of the transformer
Why oc test done in lv side?
In OC test , the equipments are connected in LV side since we need to get rated voltage . if it is cinnected in HV side the value of voltage will be less and current wil be more.Hence the ordinary instruments cannot measure this value of current
What is difference between VCB and ACB?
VCB (vacuum circuit breaker) is used in HV (high voltage) applications. ACB (air circuit breaker) is used in LV (low votage) applications.
What is the full form of hv?
What is fullform of hv
