Technical Specification for A.C. Single Phase, 2 Wire ... - WBSEDCL

11.13 Meter should have a permanent indication in its display as well as logging oftamper in case of removal of top cover, even in power off condition and itshould not disappear even if cover is re-fitted.11.14 Sealing Arrangement: The sealing screws used for the meter cover shall be fixedupside down so that these are tightened from the rear or screw less design forfixing the base and cover but provision for sealing arrangement must be there. Arun through screw (stud) has to be provided from bottom side & sealing is to bedone on the top side of the meter. Two independent sealing screws are to beprovided at each sides of the meter casing. The sealing screws shall be TinnedBrass or Nickel Plated Steel/Brass. In addition to the sealing screws provided tothe meter cover, the sealing screws of the terminal cover should also be TinnedBrass or Nickel plated steel.Meters must be supplied with two no manufactures’ seal between meterbase and cover at both sides.12.0 ANTI-TAMPER FEATURESThe meter should have the following anti-tamper features and should record andregister forward energy accurately under the following conditions :i) Input phase and neutral connections are interchanged. Reverse powerindication LED should be provided or indication should be in display circuit.ii) Incoming mains is connected to outgoing terminals and load is connectedto incoming terminals.iii) Any combination as permissible in all four connecting points should notaffect the accuracy of the meteriv) Load return is connected to a local earth and not returned to the meter aswell as the phase and neutral at supply side are reversed.v) Occurrence of combination of `(ii) and (iv)‟ or (iii)‟ and (iv)‟vi) A part of the load is returned to a local earth and the other part is returnedto the meter. “Earth load indication “should appear in display with logging oftamper, if difference between phase current and neutral current liesbetween 6% to 10%.