Frequently Asked Questions ( FAQ )  

Relay Test Kit

What is a relay test kit ?


A relay test kit is an equipment which is used for testing different type of relays. Relay test kit is a combination of programmable current and voltage sources and a timer . During relay testing Relay test kit injects fault in the relay (in form of CT & PT ) and measures the tripping time or reaction time of the relay. If the behaviour of the relay is as per its settings then the relay pass the test else relay fails the test .




Why automatic relay test kits are preferred over traditional ( variac based ) relay test kits ?


Automatic relay test kits have various advantages over traditional kids

1. Signal Stability : The output the current and voltage output of automatic relay test kit is not proportional to its input power supply it means the current and voltage output of relay test kit are getting supply from analogue to digital and then digital to analogue conversion backed with a feedback loop hence the output signals off relay test kit are not dependent on its input power supply . Automatic Relay Test Kit output are stable even if there's there is some minor instability in the input power supply

2. Accuracy , Resolution and functionality : With automatic relay test kits user can vary phase frequency and magnitude of all current and voltage signal independently with very high resolution and accuracy. This is not possible in traditional secondary injection kits which can increase or vary only magnitude ( V or I ) with the help of manual variac.




What is a numerical relay test kit?


Numerical relay test kit is an another name for automatic or microprocessor based relay test kits . Numerical relays generally high accuracy which can be tested with highly accurate automatic relay test kits




What is a universal relay test kit ?


Universal Relay Test Kit is another name for automatic relay test kits as user can vary phase , frequency and magnitude of the current and voltage sources independently and generate any type of fault .




What is 6 Phase relay Test Kit , when there is only 3 phase CT or PT in power system ?


Many customers are confused with the notation of 6 phase relay test kit . The high end relay test kits have six current sources whose phase frequency and magnitude can be varied independently . These 6 current sources are very useful in testing a differential relays.




What is need of advance software with Automatic Relay Test Kits ?


As we know that each fault is generated due to variation of Phase, frequency or magnitude in CT or PT signal , Few fault simulations are not very simple ( like testing Quadrilateral characteristics of Distance Relays ) . Advance software are very useful in simulating complex faults . Kingsine User gets all in one advance software in their standard purchase .




Why high current and voltage amplifiers are desirable in relay test kits


It is truly said that Current and Voltage sources are the soul of relay test kit .

High current and voltage signal is useful in below ways

  1. For testing 5A Over Current Relays at 10 Times , we have to inject 3X50A , which is possible with high current relay Test Kits
  2. With higher current we can test a differential relay at higher point of BIAS Curve .
  3. With higher Currents we can simulate higher faults in Transient Fault Playback .

Kingsine Test Kits have the highest Current Rating sources of 0 to 35A each ( @450VA ) and 0 to 300V each ( 124 VA )




Why high power amplifiers are desirable in relay test kits ?


Relay Test Kits with high power amplifiers are preferred as high power is required for testing the electromechanical relays . Also if a relay test kit is having higher power rating then its duty cycle is high, better heat dissipation and loading, hence more rugged design . Kingsine is having most powerful current sources of 480VA ( @35A ) each and most powerful voltage sources of 124VA ( @310V ) each




What is more important , Advance software or powerful hardware in selecting an automatic relay test kit ?


A powerful hardware is most important for long time robustness of a relay test kit, Few application needs high powered sources also .

An advance software is a tool which helps user to test even most complex relays in the easiest way .

Hence in today’s scenario relay test kit shall be a combination of high rated sources and advance software . K3063i is a good combination for both




Why Kingsine relay test kits have highest power rating in market ?


In Kingsine each current Source is of 480VA @35A and Voltage Source is 124VA@310V , hence highest in the market .




Why Kingsine K3063i is the best combination of power and accuracy ?


K3063i is having high powered voltage and current source ( current Source is of 480VA @35A and Voltage Source is 124VA@310V) while it is having current range of 3 A, which leads to very high accuracy in lower currents .




Whom to contact for any KPM’s test equipment support  ?


Feel free to contact our Technical Consultant on Consultant@kpmtek.com for any queries .




Where is the service centre of Kingsine relay test kits located in INDIA ?


We have an advance service center in Gurgaon, Haryana with 100% spare availability .




What is df/dt relay , Can I test it using Kingsine Relay Test Kits ?


Rate of Change of Frequency (ROCOF or df/dt) relay is used for fast load shedding, to speed up operation time in over- and under-frequency situations and to detect loss of grid.

ROCOF or df/dt relays are particularly effective in arresting the frequency collapse of a grid in the event of sudden loss of major generation. This is because by measuring the frequency decay rate, the corrective action can be initiated much ahead of the time when frequency of the synchronous interconnection would have actually dipped to a point at which generator under-frequency relays or unit auxiliaries would trip / operate leading to a complete system shutdown. The df/dt is used for load shedding in situations where sudden loss of generating capacity on a system will be accompanied by a decrease in system frequency. In such a situation of load Generation mismatch, the system frequency tends to fall. The df/dt relay can control the circuit breakers and allow feeders to be disconnected from the network, one by one.

In Kingsine Software there is a specialised module for testing of df/dt




What is distance relay , Which relay test kits can test these relays ?


A Distance relay / impedance relay is a voltage restrained overcurrent relay. The relay measures impedance up to the point of fault and gives tripping command if this impedance is less than the relay setting Z. Relay setting Z is known as replica impedance and it is proportional to the set impedance i.e. impedance up to the reach of the relay. The relay monitors continuously the line current I through CT and the bus voltage V through PT and operates when the V/I ratio falls below the set value.

In Kingsine both K68i & K3063i have specialised modules for testing of distance relays .




Why high power  relay test kit is required for testing a electromechanical relays


Electromechanical relays have high impedance coils , during testing relay test kit has to inject current via coils of high impedance hence high burden is required . Kingsine kits have highest burden hence ideal for testing all type of relays .




What is advance Transient playback function of automatic relay test kit ?


Now a days all advance relays comes with a fault recorder function . Whenever fault strikes this fault file gets saved in relay in form of .cfg / comtrade file . Relay test kit have the feature to import this file in its software and replay the file using its current and voltage sources . This is called as Transient playback feature.




What are the precaution with connections to kept in mind while operating relay test kit ?


Few of the site precautions are -:

  1. All the CT and PT terminals which are to be connected to relay test kit shall not be live .
  2. Earthing shall always be connected to the kit .
  3. During testing high current surge equipment such as welding sets shall be avoided in the same power supply circuit of relay test kit .
  4. Always work as per relevant local or international standard of testing .




What type of protection features are existing there in Kingsine Automatic Relay Test Kits ?


Kingsine Relay Test Kits have below protections

  1. Short Circuit protection got Voltage Amplifiers
  2. Open circuit Protection for current amplifiers
  3. Over Heat Protection .
  4. Health Earth Indication etc.




I want to test Differential Relays which type of relay test kit is more suitable for me ?


For testing differential relay on 3 phase basis we need 6 Current Source relay test kit i.e. K3063i , We can test a differential relay on phase to phase basis also using a 3 current source relay test kit , K68i





Tan Delta Test Kit

What is Tan Delta Kit, Tan Delta Test | Loss Angle Test | Dissipation Factor Test


An insulator when is connected across line and earth, it behaves as a capacitor with some effect of resistance because of impurities . Tan delta is ratio of Resistive Current ( Ir ) W.R.T Capacitive Current ( Ic )




Is KPM-TD12 ,difficult to operate ?


​​​​​​KPM TD 12 is a powerful tan delta kit with easiest operation . For any clarifications please feel free to contact our Technical Consultant on consultant@kpmtek.com




Which equipment can be tested using Tan delta Test Kit - KPM TD12 .


KPM TD 12 is capable of testing Power Transformers ( LV , HV & EHV ), CT , PT , Grading Capacitor etc. KPM TD12 can also be upgraded for testing Oil Tan Delta & Generator Tan Delta Testing .




Why we need a separate arrangement/accessories to perform Tan Delta Testing of Generators .


The capacitance of few generators are very high , hence their leakage current is out of reach of the internal power sources of tan delta kits. To conduct tan delta testing of generators different manufacturers have different methods such as resonating inductor or external power sources etc.




How can we test Oil Tan Delta using KPM TD 12 Tan delta Test Kit ?


We can connect an oil test cell to KPM TD 12 which heats the oil sample and conduct the tan delta testing as per international standards .




Is KPM TD12 a bulky equipment with huge dimensions and weight?


KPM TD12 is of only 28KG with smallest dimensions in comparison to peers ie. 350mm(L)×270mm(W)×270mm(H) Portability makes it one of the most preferred equipment to travel with , highly preferred by customers with movement . KPM TD 12 when mounted on JUMBO TRUCK is very easy to move even in uneven ground conditions of substation with all arrangements of Tools , HV and LV Cable Drums & Connectors .




I am having doubt in connections of KPM TD12 , Whom To Contact ?


Connections are very critical during Tan delta Testing . The idea is to understand the path of leakage current flowing from HV conductor to LV Conductor via insulation . During any confusion feel free to contact our Technical consultant on consultant@kpmtek.com




Does KPM-TD 12 Tan delta kit always comes with a Jumbo Truck Trolley?


Jumbo Truck is optional , User can purchase KPM TD 12 without Jumbo Truck also . In That case Customer wil get a KPM TD12 unit with a soft carry bag with all Cable & Accessories .




What is the use of Jumbo Truck Trolley .


KPM TD 12 when mounted on JUMBO TRUCK is very easy to move even in uneven ground conditions of substation with all arrangements of Tools , HV and LV Cable Drums & Connectors . Jumbo Truck can be folded to 50% of its size , making it an ideal trolley for travel also . Jumbo Truck can be customised for any KPM Product .




How to perform Calibration of KPM TD 12


Calibration of KPM TD12 can be done using Calibration Capacitor Model , KPM SC-100pF , a 10KV , 100pF Standard Capacitor





CT PT Analyzer

Which type of CT’s can be tested by KPM CT PT Analyzer ?


KPM CT PT Analyzer is capable of testing nearly all type of CT and PT which includes Metering as well as protection CTs . In terms of applications all type of CTs used in power distribution , transmission and generation can be tested using KPM CT / PT Analyzer . Special application CTs such as bus duct ring CT , Transformer Bushing CT can also be tester . KPM CT PT Analyzer can test a PT & CVT also using a Voltage booster Accessory .




Can KPM CT PT Analyzer test Generator Bus Duct CTs ?


Yes KPM CT PT analyzer can test Generator Bus Duct CTs with perfection .




Can KPM CT PT Analyzer test Power Transformer Bushing CTs  ?


Yes , KPM CT PT Analyzer test Power Transformer Bushing CTs with perfection .




Why Testing a Power Transformer Bushing CT is a complex affair for any CT Testing Equipment ?


KPM CT PT Analyzer works on the principle of Voltage Ratio Method . While testing a Power Transformer Bushing CT, the primary circuit is connected to Power Transformer Winding in series which makes the testing complex . KPM CT PT analyzer with the help of its noise reduction circuitry is capable of testing Power Transformer Bushing CT with perfection .




What is the highest knee point tested by KPM CT PT Analyzer .


KPM CT PT Analyzer saturates the core of CTs with high knee point using reducing frequency principle . So practically it can test the knee point of all type of EHV Protection CTs using its low voltage source . Theoritically it can test even 35KV Kneepoint .




Is KPM CT PT analyser portable ?


KPM CT PT Analyzer is highly portable with Size (WXHXD) in mm 485 X 356 X 183 & Weight < 15Kg. This makes it an ideal equipment to travel with .




Which type of power sector customers are using KPM CT PT Analyzer


KPM CT PT Analyzer is used by all type of customers which are in Generation ,Transmission as well as distribution of energy .




Can we measure primary and secondary resistance of a PT using KPM CT PT analyzer


The primary winding resistance of PT is in Kohms . KPM CT PT Analyzer is having resistance range in Kohms, with the help of which it can easily test primary resistance of a PT . Secondary resistance of PT is in ohms which can be easily tested .




Can we get a hysteresis curve of a CT using KPM CT PT analyzer


Yes KPM CT PT analyzer is having a hysteresis curve function. By the end of test the Hysteresis curve of CT is calculated which clearly shows the power loss characteristics of the the CT under Test .




What is hysteresis curve and what is its relevance


The magnetization of ferromagnetic substances due to a varying magnetic field lags behind the field. This effect is called hysteresis, and the term is used to describe any system in whose response depends not only on its current state, but also upon its past history. In KPM CT PT Analyzer the Hysteresis curve of CT is calculated , Width of the Hysteresis curve clearly shows the power loss characteristics of the the CT under Test .




How KPM CT PT analyzer can automatically find a winding resistance value @75’C.


KPM CT PT analyzer is having onboard temperature sensor with the help of which it measures the room temperature at the time of winding resistance testing, Once testing is complete it shows the winding resistance value at room temperature and also the winding resistance temperature compansated value @ 75'C automatically . This reduces chance of any human error due to manual entering of temperature data .




What is CT secondary burden test and what is its relevance


All type of CTs & PTs are designed for a fix burden of load to support . If the connected burden of a CT is more than the required burden then the CT output will not be as per specifications and error will be introduced . KPM CT PT analyser is having a burden testing feature in which KPM CT PT analyzer finds the VA of the complete loop of conductor .




Which test can be conducted using KPM CT PT analyzer ?


Below test can be conducted on CT and PT using KPM CT / PT Analyzer Tests for Current transformer: Excitation curve and parameters test Turns ratio test Ratio and phase error test Polarity mark check Coil resistance measurement Secondary loop burden measurement Error line curve test for protection CT Transient CT parameters test CT nameplate guess Saturation hysteresis loop curve measurement Tests for Voltage transformer: Turns ratio and phase angle error test Polarity test Secondary burden test Winding resistance test