Table of Contents
Advertisement
Maintenance
7.1.2
Measuring times
ZMD400xT
ZFD400xT
U
= 58 to 230 V
n
I
= 1 A, 5 A
n
7.1.3
Optical test output
Test mode
D000062026 en a – E650 Series 4 – ZMD400AT/CT, ZFD400AT/CT – User Manual
For technical reasons, greater measuring deviations can occur during
short-term measurements. It is therefore recommended to use sufficiently
long measuring times in order to achieve the required accuracy.
Table of measuring times required at the optical test output:
Measuring uncertainty
Current
3 P
% I
cosj=1
n
1
40 s
2
20 s
5
10 s
10
8 s
20
6 s
50
6 s
100
6 s
200
6 s
3 P = universal
1 P = single-phase
The red optical test outputs on the meter above the LCD should be used for
meter testing. These supply pulses at a frequency dependent on the meter
constant R, whereby the rising edge is always decisive for the test.
Note that the digital signal processing provides a delay of 2 seconds
between the instantaneous power at the meter and the appearance of the
pulses at the optical test outputs. No pulses are lost.
The number of pulses per second for the desired power is obtained by
multiplying the meter constant R by the power in kW divided by 3600.
Example:
Meter constant R = 1000
Power P = 35 kW
f-test output = R x P / 3600 = 1000 x 35 / 3600 = 10 imp/s
Depending on the parameter setting of the behaviour of the pulse LED, the
test mode enables you to select which measuring value (active, reactive, I²,
U²) is shown on the optical test output.
In the display, values for active, reactive and apparent energy are available.
Depending on parameter setting, the resolution of the display register can
be increased for faster testing. In the test mode, the resolution is increased
by one decimal point compared with the normal mode. A maximum of 5
decimal points is possible.
0.1%
1 P
3 P
1
0.5
cosj=1
40 s
90 s
20 s
40 s
10 s
15 s
8 s
10 s
6 s
8 s
6 s
6 s
6 s
6 s
6 s
6 s
Measuring uncertainty
0.05%
3 P
1 P
1
80 s
80 s
160 s
40 s
40 s
16 s
16 s
14 s
14 s
12 s
12 s
12 s
12 s
12 s
12 s
12 s
12 s
© Landis+Gyr
85/96
3 P
0.5
80 s
32 s
18 s
14 s
12 s
12 s
12 s
Advertisement
Table of Contents
