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

Physical examination of the meters.Non-registration with Voltage along at 70% V ref and at 120% V ref.Starting current at 0.2% I basic UpfHigh voltage test.Insulation resistance test.Test of protection for withstanding 433 volt between phase & neutral for a period of atleast 4 hours without any load.Test of endurance up to 150% I maxDuring the above tests, if no of meter fails is less than or equal to 1 no., the lot shall beconsidered to be conforming to the above tests. If no. of meter fails is greater than 1 no. butless than 4 (four), further re-sampling will be done and the numbers of re-sampled metersshall be 32, selected at random from the said Lot of 20,000 nos.The re-sampled meter will again be subjected to the tests as mentioned above and if numberof meters in two samples (combined) 64 (sixty four) nos. is less than 4 (four) nos., the lot shallbe considered to be conforming to the above tests otherwise rejected.Further testing for 8 nos. meters selected from 32 nos. sample meters will be carriedas follows :Limits of error on all the sample meters at :1% I basic 1.0 pf. (±2% is preferable but should not exceed ±3%)2% I basic 1.0 pf.5% I basic 1.0 pf., 0.5 pf. Lag & 0.8 lead10% I basic 1.0 pf., 0.5 pf. Lag & 0.8 lead50% I basic 1.0 pf., 0.5 pf. Lag & 0.8 lead100% I basic 1.0 pf., 0.5 pf. Lag & 0.8 lead200% I basic 1.0 pf., 0.5 pf. Lag600% I basic 1.0 pf., 0.5 pf. LagTest of meter constant and meter dial for one unit at 200% I basic, 0.866 pf.Lag.Power loss on voltage & current circuit.Further testing for 3 Nos. sample meters will be carried as follows:Repeatability of error test at 5% I basic Upf & 100% I basic Upf.The maximum divergent should be less than 0.5%.If anyone of the meter fails on any of the above tests, the lot will be rejected.Further testing for 1 No. sample meter will be carried as follows:Magnetic induction of external origin (AC & DC).Electro Static Spark Discharge of 35KVpTamper and Fraud protection as per Clause 12 ( I to vii) (Anti-tamper feature)of our specification.Injection of DC pulse (low frequency) in the neutral.Dry –heat test as per clause 12.6.1 of IS: 13779/99.At least one sample selected from any lot of the meters offered for inspection will besealed by us and handed over to the supplier for testing at NABL accreditedlaboratory. Presence of purchaser‟s representative during dry heat test at NABLaccredited laboratory is not required. But in the test report meter Sl. No. & meterbody seal nos. is to be mentioned.