Masana a Maimaita da Takarda Masu Yawancin Kula

1). Ina so ina muhimmanci na relay ta over current da yake koyarwa?

Zama a kan lokacin da yake koyarwa ya zama da yake sa shi a kan lokacin da yake koyarwa ya zama da yake sa shi a kan lokacin da yake sa shi.

2). Kari iyakokin da dama na contact relay.

• An bukatar girman tsarin.

• Na nuna (yan-kashe-kashe yan-kashe).

• Yana da damuwa da korona.

• Yanayin da damuwa da tsafta da ba da wasu.

• Yana iya bar ra'ayin da aka fada da kuma ra'ayin da aka ci gaba.

3). Tashar da pickup value & reset (ko) dropout value

Pickup value:

Shi ne babbar da yake koyarwa; idan yake koyarwa ne da 0 zuwa pickup value, relay yake koyarwa.

Reset (ko) Dropout value:

Shi ne babban da yake koyarwa; idan yake koyarwa ne da take da pickup value, relay yake koyarwa (ko) de-energize.

4). Kari iyakokin da dama na relay da aka fara.

Relays commissioning checks on

• Kari pickup da dropout values.

• Resistance da yake da contacts da coil relay.

• Time delay (idani relay ba za a iya instantaneous), verification da lokacin da yake yi operation ta relay.

• Kari cewa circuit breaker trips bayan activation ta specific relay.

• Contact continuity checks bayan relay energisation.

• Kari cewa plug-shorting contacts su ne.

• Kari cewa CTs da PTs su ne rectified a cikin polarity da zai.

• Relay burden assessment.

• Primary injection test.

• Secondary injection test.

5). Bayyana I.D.M.T.

IDMT yana nufin inverse time relay da wata lokaci da aka fadada.

6). Muhimmanci da negative sequence reactance?

Idan akwai takamta a cikin system, ana iya faru negative sequence. Muhimmiyar da suke suka faru shine cewa suke yi field da yake sauti a nan da yake sa main field.

7). Muhimmanci da zero sequence reactance?

Idan machine an da ita neutral, system earth fault yake sa zero sequence current a machine.

8). Muhimmanci da over current relay (Inverse)?

Shi ne self-powered inverse time over current & earth fault relay da ake amfani a cikin systems da aka fada don

• A.C. machines,

• Transformers,

• Feeders, etc.

don selective phase and earth fault protection.

Adjustable inverse time/current induction disc relay da wata lokaci da aka fadada da yake non-directional da substantially damped.

Relay yana da low burden & low overshoot da high torque movement. Relay disc yana da shape da ake sa shi a haka cewa lokacin da yake sa shi, driving torque yake sa shi da yake cancel out control spring’s fluctuating restraint torque.

9). Muhimmanci da CMM relay da standard Inv. O/C current relay?

Idan current yake da take da inv. O/C relay underprotects da overprotects idan current yake da take.

CMM: takes into consideration both +ve and -ve sequence currents,

i.e., single phasing

Imbalance supply conditions & gives the -ve phase three times the weightage and +ve sequence current heating is more efficient than +ve sequence current heating.

In terms,

Net Rotor Heating = I12 + 3 I22

As a result, the CMM relay protection feature is highly related to motor heating characteristic. As a result, it is also superior to a thermal overload relay.

10). Muhimmanci da anti-pumping relay?

Idan closing signal yake da shi a nan bayan breaker yake close, anti-pumping relay yake activate, da kuma breaker ba zan iya close again bayan tripping.

11). Muhimmanci da lock out relay?

Shi ne relay da ke bude circuit breaker da aka close bayan tripping (protection) bayan operator yake tattaune.

12). Muhimmanci da 86 a cikin relay terms?

Idan ba a da shi fault sensing capabilities & relevant in substation protection, master trip relay (or) lockout relay, recognized by ANSI code 86, performs a significant function as an intermediator connecting the protection relay and control points.

13). Muhimmanci da relays 86.1 da 86.2?

For automatic restoration in EMTR (Electrically Detected Magnetic Resonance), all electrical protection is connected to 86.1 relay, & under voltage protection is connected to 86.2 relay.

14). Muhimmanci da fuse failure relay?

This relay prevents inappropriate circuit breaker tripping by detecting a failure or unintentional removal of the voltage transformer secondary fuses. This relay comprises of a hinged armature unit that is operated by rectified AC electricity. A common relay for three phases is created by winding three coils