Custom Resistor Installation And Wiring - ABB ACS800 Hardware Manual

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Custom resistor installation and wiring

Effective cooling of the resistors must be ensured.
WARNING! All materials near the brake resistors must be non-flammable. The
surface temperature of the resistors is high. The temperature of the air rising from
the resistors is hundreds of degrees Celsius. Protect the resistors against contact.
For a resistor cable, use a shielded cable. The maximum length of the resistor cable
is 10 m.
A recommended copper cable size for connecting the user-defined resistor to the
brake unit is as follows:
• 400 V brake unit: 3 x 95 mm
• 500 V brake unit: 3 x 95 mm
• 690 V brake unit: 3 x 120 mm
For protection against overheating, resistors with thermal circuit breakers (standard
in ABB resistors) should be used. The circuit breakers should be wired to the
ENABLE inputs of the brake choppers.
WARNING! The ENABLE input terminal blocks of the choppers are at intermediate
circuit potential when the supply unit of the ACS800-07 (+V992) drive is running.
This voltage is extremely dangerous and may cause serious damage or injuries if the
isolation level and protection conditions for the thermal circuit breakers are not
sufficient. The normally-closed breakers should always be properly isolated (over
2.5 kV) and shrouded against contact.
Note: For the ENABLE input wiring, use a cable rated as follows:
• twisted pair (screened type recommended)
• rated operating voltage between a core and earth (U
• insulation test voltage > 2.5 kV.
Resistor braking
2 2
+ 50 mm
2 2
+ 50 mm
2 2
+ 70 mm
): ≥ 750 V
0