MG 47 Series - Wiring Input Signal

1847LHZ EM-9517-B Rev.10
MG CO., LTD. www.mgco.jp
5-2-55 Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
1.6.4 WIRING INPUT SIGNAL
Connect AC voltage signal wires.
IMPORTANT
• The input voltage must be 50 – 300 V AC.
• Prepare a voltage transformer (VT) with 300 V or less secondary voltage.
• When the input voltage is 300 V or less, direct input is available without using a VT.
• With direct input without a VT, do not ground the input circuit.
• With a low-voltage circuit, grounding the VT secondary is not necessary.
• While voltage is applied at the VT primary, shortcircuiting the secondary generates overcurrent at the secondary and
may cause a breakdown, a burnout accident, or an interphase shortcircuit. Do not shortcircuit the secondary.
• To prevent expansion of a possible shortcircuit accident at the VT primary, use a VT with fuse, or mount fuses or a
circuit breaker at the primary. Also to prevent the VT from being overloaded or damaged by shortcircuiting at the sec-
ondary, mounting fuses or a breaker at the secondary is recommended. Even without using a VT, it is recommended to
mount fuses or a breaker in order to prevent expansion of a shortcircuit accident.
• The input waveform must be up to 15% of 3rd harmonic content.
• For safety, make sure that wiring is performed by qualied personnel only.
• In order to prevent potential electric shock, wire the unit after cutting the input signal and making sure that the power is
not supplied to the cable.
• Use wires as thick as possible.
• Ground with the resistance 100 Ω or less.
• Do not connect anything to unused terminals.
Input
VT
V±
123
u
V
LOAD
SOURCE
Ground
(resistance
100 ohms or less)
U
v
FUSE FUSE