1. Usage,Characteristic and accommodation

In accordance with standard of GB/T17215 and GB/T8382, DDSY-855 single phase prepaid kilowatt hour meter(hereafter to meter) is adopt to the structure of complete shield and seal and the technology of micro-electron to measure the power and the advanced singlechip processing system to collect, process and conserve, which has good anti-electromagnet,low power loss,high precision,high over-load,long life,anti-damage,anti-copy,and convenience.

The main characteristic: execute the computer management, Purchase the electricity before using, which can limit the maximum using power(limited by power supply department)

One card for one meter, special card for special use, loss the card without losing the electricity and can reuse buying another card.The electrical card can transmit the data in two ways. It can cut off the electricity and warn the customer of purchasing electricity. It will be cut off automatically when the power is zero. It has the certainly anti-steal software designs.

DDSY855 series kilowatt hour meter is adapt to measure the active power electrical quantity which thefrequency of 50Hz or 60Hz and installed in the box outside or inside. This meter is adapt to -25℃~+55℃of the environment temperature and no more than 85% of relative humidity and should no corrasive air around.

2,Specification and technical target

2.1 Specification

Type	class	Referenced current	Referenced voltage
DDSY855	1 / 2	2.5/5/10/40A	220V~240V

2.2 Basic error (the maximum of balance load error)

Current	Power factor(COS?)	Basic error(%)
		1	2
0.05Ib	1	+1.5	+2.5
0.1Ib-Imax	1.0	+1.0	+2.0
0.1Ib	0.5L 0.8C	+1.5	+2.5
0.2Ib-Imax	0.5L 0.8C	+1.0	+2.0

Note:(Ib rated current Imax maximum current)

2.3 Starting

In the condition of referenced voltage, referenced frequency and Cos? equal to 1.0, the meter can go on measuring the electric quantity with load current of 0.004Ib(class1),0.005Ib(class2).

2.4 No-load Starting

The tested output of meter should not be generated more than one impulse when imposing 115% on the voltage circuit and no electricity in the current line.

2.5 Power loss

Power loss: ≦2W

2.6 Using condition

working voltage range:220V+20%

standard working temperature: -25℃~+55℃

relative humidity: 85%

3.The main structure and work principle

Type DDSY855series three phase pre-paid kilowatt hour meter is adopt to special large scale integrated circuit from importing and digital sampling process technology and new type meter of SMT technics,which is sixteen in digital, AD Transfer, Digital multiplier unit.

3.1The diagram of work principle

Getting the voltage sampling signal and current sampling signal through regulation resistance and current inter-induction, the kilowatt hour meter receive the multiply signal via digital multiplier unit then generate the count impulse which the frequency and the multiply of current and voltage are in the direct proportion via the transfer of frequency. It can drive the electric motor to measure the electric quantity through demultiply.

3.2 Data processing

Electric power measurement impulse is processed by CPU through photocoupler, and then stored in the EEPROM not easy to loss after calculating. With the computer management information system, IC card of certain electrical quantity and monitor required is read to micro-processing system inside the meter through the IC reader and then it provide showing, alarm and the signal of cut offafter the calculating of CPU.

4. Installment and usage

4.1 The meter can be installed and used with the sealing through the test before leaving the factory .If no sealing or store too long ,it can be usage through retested and resealed by the relative department.

4.2 The meter should be vertical and not slope to install in the dry and winding place which its height is nearly 1.8m. The base should be fixed in the firm, anti-fire and unshakable wall.

4.3 Connection according to the diagram and screw tight the connecting screw and screw the connecting board in the terminal.

4.4 The red window in the name plate stands for decimal and the black is integer. The practical electrical quantity of meter which connect through inter-induction is the showing multiply the various proportion.

4.5 The customer should put the card to car reader once so as to send the data inside the meter back to computer database. Before purchasing the electricity.

4.6 We put the card into the car reader and operate the computer at the same time to make the customer code, the electrical quantity buyed, limited capacity and limited power read into the card with a password.

4.7 Put the card into the car reader when using. If it is a valid card, the meter read the data automatically and the database show the remanent electrical quantity(three seconds) and plus general electrical quantity(twelve seconds), then take the card and protect the card safely.

4.8 If the customer want to know the remanent electrical quantity, it can be shown by put the card. When the meter is processing.

4.9 If the monitor shows the remanent electrical quantity and the indicator light of beyond capacity illumes at the same time, it warns the customer of using the electricity beyond the capacity when the meter is processing. If the customer is set to cut off when beyond the capacity(the indicator light of limited capacity illumes), it will be cut off for three minutes after twinkling showing the remanent electrical quantity in 30 seconds and count down showing the time of recovering supplying the power. If the meter is response to put into the car reader, it will be supplied by power at once.

4.10 The card owned by the customer can not exchange, which one card for one meter, and it has to go to the power department to buy another card when missing.

4.11 The meter is cut off and warned and the indicator light illume when the remanent electrical quantity is 10% of this purchasing electrical quantity. It will be recovered by supplying power when put the card into the car reader .If can’t find the card for this meter when it is cut off , it can use the neighbor’s card instead of our meter to recover the power.

4.12 If the meter is continual to work and force the indicator light to illume when the remanent electrical quantity is zero, the user should buy the electricity at once and tell the truth to the power department.

5.The time of guarantee

Within the eighteen months from the meter leaving the factory,Our manufactory give it free for repairing or changing when finding the meter not compliance with the technology, which on the condition that the customer should do according to the operation operating manual and the sealing is complete in the manufactory.

6. External dimensions:

7.Connection diagram of function terminal