MTE PTS 400.3 PLUS - Recommended Test Points for Active Energy 4-Wire Measurements

PTS 400.3 PLUS Operation Manual_R02 Page 237/306
B) Impulse cables with foreign instruments involved
• Exact instrument type
• Detailed technical specification of input/output of foreign instrument (signals, supply)
• Connector type and Pin assignment
Based on this information MTE/EMH will check, whether a simple cable or a cable with built-in
adapter is needed and then offer the cable.
Special impulse cables / adapters are not on stock. They are manufactured upon order
Recommended test points for active energy 4-wire measurements
It is recommended to check minimum one load point within each internal voltage and current range at
power factors PF = 1, PF = 0.5 (+60°), PF = 0.5 (300°) for phase L1, L2, L3 and 3 phase L1-L2-L3.
The influences of voltage, current and frequency variations on each other are very small. Therefore,
the current (load curve), voltage and frequency dependency can be tested separately.
The following definition of test points as used in the factory calibration certificate can be taken as ref-
erence.
If the customer needs direct traceability for special load points (U, I values as used in later daily
work), additional connection and measurement modes, these additional test points should be agreed
and defined between customer and testing laboratory.
Table 1-1: 3-phase 4-wire active energy measurements with direct current inputs 12A
Load Curve and Voltage Dependency (f = 53 Hz)
Un [V]
65
130
260
520
In [A]
I[A] \ U[V]
60
120
240
480
0.0025
0.002
•
0.005
0.004
•
0.012
0.01
•
0.025
0.02
•
0.05
0.04
•
0.12
0.1
•
•
•
•
0.25
0.2
•
0.5
0.4
•
1.2
1.0
•
2.5
2.0
•
5
4.0
•
12
10.0
•
Frequency Dependency
f [Hz]
U = 240 V
I = 1 A
45
•
50
•
55
•
60
•
65
•
• Each mark represents 3 load points at PF=1(0°), PF=0.5(60°), PF=0.5(300°),
each with 4 error results of energy measurements single phase at L1, L2, L3 and three-phase L1-
L2-L3 (Total 12 results).