ABB ACS880-0500-3, Руководство по оборудованию

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WARNING!
The materials near the brake resistor must be non-flammable. The surface
temperature of the resistor is high. Air flowing from the resistor is of hundreds of
degrees Celsius. If the exhaust vents are connected to a ventilation system, make
sure that the material withstands high temperatures. Protect the resistor against
contact.
Selecting the resistor thermal switch cable
Make sure that the cable connecting the resistor thermal switch to chopper control unit
meets the following requirements:
• shielded cable
• rated operating voltage 0.6 kV / 1 kV ( U
0
/U )
• insulation test voltage > 2.5 kV
• jacket material for at least 90 °C (194 °F). Take into account further requirements due
to resistor construction and temperature.
Protecting the system against thermal overload
The brake control program includes a resistor and resistor cable thermal protection function,
which can be tuned by the user. The brake chopper protects itself and the resistor cables
against thermal overload. Make sure that the following conditions are met:
• The resistor assembly is equipped with a thermal switch, which is connected to chopper
control unit input.
• The cables are dimensioned according to the nominal current of the drive.
￭ Operation principle
If the resistor overheats, the thermal switch opens and interrupts the chopper control unit
input signal. Upon a fault, the control unit relay output either opens the drive main circuit
breaker or gives a fault indication to the overriding control system, which takes care of the
protection.
For more information on the thermal protection function, see the appropriate firmware
manual.
Protecting the system against short-circuits
The brake unit is equipped with fuses as standard.
The fuses protect the brake chopper, the brake resistors and the brake circuit cables in a
short-circuit situation.
Guidelines for planning the electrical installation 35