DDSF284 is a single-phase static multi-tariff meter with large-screen display, which is based on the special measurement chip and inner clock to measure active energy with several tariffs as time of use by connecting up resident power supply system. It has the merits of high reliability, easy meter reading, high over-load capability and firm construction. 1. Basic Functions 1. 1 Large- screen display. 1. 2 Accumulating bi-directional active energy measurement. 1. 3 Time-of use measurement. 1. 4 Operation indicator of peak period and off-peak period 1. 5 Broadcasting time synchronization. 1. 6 Energy frozen on billing day. 1. 7 Passive pulse output (optical coupling isolated). 1. 8 Infrared communication. 2. Optional Functions 2. 1 RS-485 interface. 2. 2 Failure alarm. 2. 3 Event log. 2. 4Second signal output. 2. 5Clock temperature compensation 3. Technical Data 3. 1 Applicable Standard: IEC 61036-2000 3. 2 Service Lifetime: 10 years 3. 3 Accuracy Class: Class1, Class2 3. 4 Working Temperature: -30C~+65C 3. 5 Working Voltage Range: 0.7~1.2Un 3. 6 Power Loss Less than: 0.8W or 1.5VA 3. 7 Clock Accuracy: Daily Error less than 0.5s 4. Specifications Rated Voltage: 110 V, 120V, 220V, 230V, 240V Reference Frequency: 50Hz or 60Hz Basic Current (Maximum Current) A 2.5(10) 5(20) 10(40) 20(80) 2.5(15) 5(30) 10(60) 20(100) Or design other specified meter