ABB NBRA-6 Series, Installation And Startup Manual

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Installation and Start-up Guide for NBRA-6xx 5-1
Chapter 5 – Fault Tracing
Fault Indications
A fault in the resistor braking circuit prevents fast motor deceleration. It
can also cause the frequency converter to trip under fault.
If a fault is detected by the chopper control board (NBRC) the braking
chopper disconnects the braking resistor from the intermediate circuit
and the changeover switch of the relay output is released. The relay
output indicates following faults:
• braking resistor or resistor cable short circuit,
• braking chopper (IGBT) short circuit,
• chopper control board failure,
• the chopper enable input signal switched off.
Note that the chopper will not be able to switch off a short circuit
current. If the relay output is used as recommended in
Chapter 4 –
Electrical Installation , the main contactor of the ACS 600 will open
upon a fault.
Fault Indication Cause Remedy
Mains supply of
ACS 600 is switched off
by the chopper relay
output. Chopper or resistor overheated (see below).
Short circuit in resistor or power cables.
No Enable input received by NBRC board.
Chopper control board failure.
Chopper damaged; it is not able to
disconnect resistor from intermediate circuit.
Check connections. Let equipment cool.
Check power cables and resistor.
Check that Enable input is on (see Chapter 4
– Electrical Installation ).
Contact local ABB representative.
Chopper does not
function. Chopper voltage setting too high.
Drive Parameter 20.5 (20.7 for ACP 600) is
set to ON.
Check voltage setting. (See Chapter 3 –
Voltage Selection and Mechanical Installation )
Set Parameter 20.5 (20.7 for ACP 600) to
OFF.
ACS 600 trips on
UNDERVOLTAGE fault. Chopper voltage setting too low. Check the voltage setting. (see
Chapter 3 – Voltage Selection and
Mechanical Installation
)
Braking resistor or
chopper overheats. The maximum braking cycle exceeded or
resistor cooling insufficient.
Chopper voltage setting incorrect or jumper
missing.
Check duty cycle and resistor cooling.
Ensure that voltage setting is correct and
jumper is properly in place.