Current and Voltage Controls Current Transformer, 3-Phase Types A 74-10, A 74-11 • 3-phase current metering transformers for use with current control relays • Measuring ranges: A 74-10 5: 0.5 5 AAC A 74-10 20: 2 - 20 AAC A 74-11 100: 10 - 100 AAC A 74-11 500: 50 - 500 AAC Product Description Ordering Key 3-phase current transformer measures on all three phases. Output voltage proportional Type Input current to measured amplitude of the rms-value of the normal phase current. A 74-10 5 Type Selection Input current Type no. 5 AAC 20 AAC 100 AAC 500 AAC A 74-10 5 A 74-10 20 A 74-11 100 A 74-11 500 Input Specifications Current range Max. current (continuously) Max. overload current (t = 30 s) Rated insulation voltage Input-output Overvoltage category Dielectric strength Dielectric voltage Rated impulse withstand volt. A 74-10 5 A 74-10 20 A 74-11 100 A 74-11 500 0.5 - 5 AAC 20 AAC 40 AAC 2 - 20 AAC 50 AAC 85 AAC 10 - 100 AAC 250 AAC 325 AAC 50 - 500 AAC 750 AAC 1000 AAC 1000 VACrms IV (IEC 60664) 1000 VACrms IV (IEC 60664) 1000 VACrms IV (IEC 60664) 1000 VACrms IV (IEC 60664) 6 kVACrms 12 kV (1.2/50 µs) 6 kVACrms 12 kV (1.2/50 µs) 6 kVACrms 12 kV (1.2/50 µs) 6 kVACrms 12 kV (1.2/50 µs) < 0.1 W@5 A < 0.25 W@20 A < 1.5 W@100 A < 21 W@1500 A A 74-10 5 A 74-10 20 A 74-11 100 A 74-11 500 0.4 - 4 Vp 0.4 - 4 Vp 0.4 - 4 Vp 0.4 - 4 Vp < 700 Ω < 200 Ω < 40 Ω < 10 Ω ± 5% ± 5% ± 5% ± 5% ± 0.1% per °C ± 0.1% per °C ± 0.1% per °C ± 0.1% per °C 250 VACrms 250 VACrms 250 VACrms 250 VACrms Power consumption Output Specifications Output voltage (TA = 20°C = 68°F), RL = 9.5 kΩ) Output impedance Tolerance of output voltage @ rated input current Temperature variation Rated insulation voltage (cable) Specifications are subject to change without notice (19.07.06) 1 A 74-10, A 74-11 General Specifications Mode of Operation Pollution degree Ambient temperature Housing A74-10 Dimensions A74-11 Material Weight A 74-10 A 74-11 Connection cable Approval CE Marking The current metering transformer is connected to the current control relays H 475 as follows: ductor through the hole several times makes it possible to meter currents below the nominal range. Red core to term. 5 White core to term. 6 Yellow core to term. 7 Black core to term. 8. (starpoint - neutral). If the conductor is drawn through the central hole e.g. 5 times, the metering transformer will register 50 A when the current in the conductor is 10 A. 3 (IEC 60664) - 20 to + 60°C (- 4 to + 140°F) 120 x 45 x 16 mm 150 x 114 x 23 ABS 200 g 750 g 2 m PVC, 4 x 0.4 mm2 UL Yes - U1. - U2. - U3. The metered conductor is drawn through the central hole of the current metering transformer. Drawing the con- In amplitude and phase the output voltage is proportional to the phase current metered. Wiring Diagrams Input current Output voltage Correct connection U1 Red Black U3 Yellow U2 White Incorrect connection U1 Red Red White Yellow Black U2 White Black U3 Yellow Dimensions A 74-10 .. 2 A 74-11 .. Specifications are subject to change without notice (19.07.06)