Inspection And Error Analysis Of Single Phase Energy Meter
1, intuitive inspection
(1) nameplate signs complete, writing clear, no obvious tilt.
(2) The numbers on the character wheel counter are all in the window cover (except the last character wheel and the character wheel in the carry).
(3) Case intact, clear glass, fixed and solid without rupture.
(4) read the number of revolutions of the color clear, the length of appropriate. Through intuitive inspection, unqualified energy meter should stop using.
2, Single Phase Energy Meter to determine the potential
Disconnect the home residual current protection device or into the household line switch, the turntable continuous rotation of not more than 1 full circle, then the Single Phase Energy Meter no creep, otherwise it should be energy meter diving.
3, Single Phase Energy Meter start performance judgment
C = 1440r / (kW · h), the starting power PQ = UxgIQ × 0.005Ib = 220 × 0.005 × 2.5 = 2.75W, the user at home in general, the user is currently the most commonly used 2.0 2.5 (10) A Single Phase Energy Meter, for example, There is no standard load of 2.75W, you can use 8W standard incandescent lamp to determine how to start the power meter, when connected to the load, 3min energy meter should be continuous rotation of not less than 1 turn, that Single Phase Energy Meter to start a good performance.
4, constant estimates At present, the ordinary energy meter marked constant unit r / (kW · h), to C = 1440r / (kW · h), for example, the user put part of the load so that the energy meter rotation, the energy meter counter When a number is changed, the turntable should be rotated by N1 = 10-abC = 10-1 × 1 × 1440 = 144r where a is the counter decimal place and is the counter magnification.) If the number of revolutions read is not 144r, Description Watt meter constant error.
5, Single Phase Energy Meter basic error estimates
Estimation of the error of the direct access meter (fixed speed measurement time) by the wattage method. Take DD702, 2.5 (10) A, C = 1440r / (kW · h) single-phase energy meter as an example.
(1) According to the user actual power equipment selected 1-2 load power points, such as 100W, 25W, select the estimated number of revolutions N, such as 5r (generally not less than 3r), calculate the set time
T1 = 3600 × 1000N / CKLKYP1 = 3600 × 1000 × 5 / (1440 × 1 × 1 × 100) = 125s
T2 = 3600 × 1000N / CKLKYP2 = 3600 × 1000 × 5 / (1440 × 1 × 1 × 25) = 500s
Where KL, KY - energy meter marked current, voltage transformer rated ratio, not marked by 1.
(2) connected to the load, with a stopwatch (you can use the phone stopwatch function) measured power meter continuous rotation 5r required time. Such as at 100W, t1 = 123s; 25W when t2 = 505s.
(3) estimate the relative error of Single Phase Energy Meter
Γ1 = (T1 - t2) / t1 × 100% = [100 × (125-123) / 125]% = 1.6%
Γ2 = (T2 - t2) / t2 × 100% = [100 × (500-505) / 500]% = - 1.0%
(4) to determine the energy meter error characteristics. According to the exact level of different energy meter, γ1, γ2 should be within the scope of the relevant regulations.
Such as ordinary users generally 2.0 Single Phase Energy Meter, the load current between 0.1Ib-Imax, the absolute value of the error should be less than 2.0, light load error when the absolute value should be less than 2.5. Through the estimation, it can determine whether the Single Phase Energy Meter meets the requirements of on-site operation. If the relative error is larger than the specified value, the user should promptly check the meter.