Protective Relay Instructions
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The Purpose of this page is to instruct people on how to fill this sheet out. There are many types of relays that may require review of that relay prior to using this test sheet. Please review the relay instructions for the relay you are testing before filling out the form. As always data integrity is extremely important for consistant results.
Date - The date that the test is being performed
Project Number - The project number that is being charged for the time to test the relay
Customer: Who is paying for the job. If there is a third party owner place a / then the owner of the equipment.
Customer Code: This is in reference to the location of the client. This could also be the ACS Master Account Number.
Location/Item Reference: - This locates where the item is located, this could also be the KH tag number if there is one available.
Item: Name Tag Information or One Line designation fo the equipment, circuit, equipment name, etc. Use enough descrption to clearly identify this device differently from any other device in the system.
Manufacturer - Who Manufactured the relay?
Serial Number - Many relays are not equipped with a unique identifyer so make sure that if it does have one that it is listed here. If not record N/A for Not Applicable.
Model Number - This is the Manufactures descriptive number to identify the relay and its features. This could also be a catalogue number
Type - This is usually a short letter description that identifys this relay to the family of products that it is associated with. This short letter description is often included in the model number.
Style Number - This is a unique identifyer that is usually limited to Westinghouse/Cutlerhammer/ABB Equipment and is often Not applicable on other manufacturers.
Function - This should reflect what the relay is used for. i.e. 51 - Time Overcurrent.
Charactoristic - This should reflect how the relay acts during operation such as Inverse, Very Inverse, Extremely Inverse, etc.
Tap Range: - This is the range of current taps that the relay is set up for. In order to establish the actual conditions it is protecting against the values must ba calculated using the Tap and the instrument transfomrer ratio. When doing a coordination study an engineer must also understnad what his options are. Recording the Tap Range provides this information. This information can become critical when repairing the relay or adjusting to a changing situation on a given circuit.
Instantaneous Range - Same as Tap Range but for the 50 -Instantaneous Function.
Target/Seal In Amps: This is typically 2.0 or 0.2 for electro mechanical relays. Leave it as N/A if it is only a contact closure. ElectroMechanical relays place a burden on the instrument transfomrer which must be compensated for when desiging the protection system so that the instrument transfomrer is not over burdened or under excited. This function is tested later so recording this value helps identify what the protection circuit has been designed for.
Instrument Transformer Ratio: This information should be tracked down as often as possible. The best way is to review the origional equipment manufactures drawings to determin the source of power for the relay. This is extremely important along with the tap setting when determining the actual conditions the relay is protecting against
Time Dial Range: This should be identlfied to allow Engineers the understanding of what the relay is capable of when reviewing repairs or changing conditions.
Instruction Book Number - This provides us with the information that the test tech used when servicing the relay. So if there is any descrepancies between what service was performed and any changes that need to be made this can easily be identified.
Curve Number - This allows us to understand what was used to reference the calibration of the relay against.
Visual and Mechanical Inspection - This is a Quality Control Check list to make sure that the relay is serviced properly.
Location/Item Ref & Item on the back are just to keep this information at the fingertips of the enginere when reviewing the data.
Test Type:
Initial - When a relay is commissioned this must be checked. This includes replacement relays for those that are defective.
Routine - Periodic checks should be done to determine if the relay is still functioning as desinged, if the check is routine, then this should be checked.
Setting Change - Often the conditions that the relay is designed to protect change and a coordination study is done to determine what these changes should be made to. When this process happens make sure that this is checked as it establishes a baseline for future results.
The next Section is where the actual results are stored. Notice that the form is designed to acomodate four single phase relays or one relay that can accomodate up to four sensing circuits.
Accross the Top:
Tap reflects the actual position of the tap screw in the relay. The Tap is often accompanied by a legend that identifys which tap that the scre is in.
Time Dial reflects the actual time dial setting that the relay is found it. This is often a thumb wheel equipped with a stopper for the tripping contact that is bound to the induction disk.
Inst.
This is tha actuall instantaneous set point. OFten this is a very corse setting located on the Instant Indicating Contactor.
Zero Adjust.
This should is accomplished by moving the time dial to zero and checking continueity of the trip circuit. At or slightly before zero the continueity light should turn on.
Pickup
Pickup is the point that operation begins. This can easily be determined on Induction Disk Relays by moving the contact to the continueity light and then adjusting the current, voltage or other quantity until the continueity light flickers.
Value A is the first condition that the relay is being tested for. This is usually a specific current or voltage that activates the operation of the relay for an expected time frame
Time A is the expected result of the condition that the relay is tested for.
Value B and Time B is for the second condition and expected result that the relay is tested for.
Target & S.I. Amps is determined by applying DC current to the Indicating Sealing Contactor that is used to provide enough power to trip the energy isolating device that it is connected to.
Instant Element is where you test the Instantaneous Indicating Contactor to see what value will cause it to operate.
The Specs Row is used to identify the expected results
The As found Row is used to record how the relay has been performing prior to service. The As Left results record how the relay is epected to perform in the future. If any adustments are made during service or if a coordination study was done and relay settings need to be changed, these values should be different, otherwise they remain the same.