Frequently Asked Questions ( FAQ )  

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 .

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.

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

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 .

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.

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 .

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 For testing 5A Over Current Relays at 10 Times , we have to inject 3X50A , which is possible with high current relay Test Kits With higher current we can test a differential relay at higher point of BIAS Curve . 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 )

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 for lower power rating is high hence more rugged design . Kingsine is having most powerful current sources of 480VA ( @35A ) each and most powerful voltage sources of 124VA ( @310V ) each

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

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

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 .

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

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

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

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 .

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 .

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.

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

Kingsine Relay Test Kits have below protections Short Circuit protection got Voltage Amplifiers Open circuit Protection for current amplifiers Over Heat Protection . Health Earth Indication etc.

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