WEG GRT7TH4 R2, Installation, Operation And Maintenance Manual

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Automatic Voltage Regulator – GRT7-TH4-R2 | 17
5 PROTECTION FUSE
The fuse is used to limit the input current supply in order to extinguish the current in case of failure, avoiding major problems.
The GRT7-TH4 R2 regulator possesses a rectifier that controls the field voltage of the generator. For the maximum field voltage,
the supplied current at input “3” is half of the field current, and the maximum current of the fuse should be a little more than half
of the current supplied by the regulator. Listed below are some of the fuse characteristics:
Recommended manufacturer: LittelFuse
Characteristics: Fast action fuse.
Dimensions: 5x20 mm.
Current/Voltage: 3A/250V for 5A model or 5A/250V for 7A model (Table 4.1).
Time for opening (to blow):
Fuse opening time
% of maximum current Opening time
110% 4 hours (minimum)
135% Max. 1 hour
200% Max. 1 second
6 STANDARDS
The GRT7-TH4 R2 voltage regulators comply with the following international standards:
Standard Level
Performance
Criterium
IEC 61000-4-5 – Surge immunity test Asymmetrical: 4kV Symmetrical: 4kV B
IEC 61000-4-4 - Electrical fast transient/burst immunity
test
5Khz repetitions, +/- 2kV peak voltage B
IEC 61000-4-3 – Radiated, radio-frequency,
electromagnetic field immunity test
10V/m field for a frequency range from 80MHz to 1GHz. A
10% maximum variation is allowed at the output voltage for a
radiated frequency between 160MHz and 280MHz. For all
other frequencies the equipment doesn’t present variations
A
IEC 61000-4-2 - Electrostatic discharge immunity test
Contact: 4kV load;
Through the air: 8kV load.
B
IEC 61000-4-11 - Voltage dips, short interruptions and
voltage variations immunity tests
Dip f 30db to 95db dips C and B
IEC 61000-4-6 - Immunity to conducted disturbances,
induced by radio-frequency fields
10V amplitude, 150kHz to 80Mhz A