ABB ACQ80, Firmware Manual

Page: 58 / 390

58 Program features
useful, for example, in applications where low noise is necessary but higher
noise can be tolerated when the full output current is needed.
Settings
Parameter
97.01 Switching frequency reference
and
97.02 Minimum switching
frequency
(page
246
).
Safety and protections
 Fixed/standard protections
Overcurrent
If the output current exceeds the internal overcurrent limit, the IGBTs are shut
down immediately to protect the drive.
Drive temperature
If the temperature rises high enough, the drive first starts to limit the switching
frequency and then the current to protect itself. If it is still keeps heating up, for
example because of a fan failure, an overtemperature fault is generated.
Short circuit
In case of a short circuit, the IGBTs are shut down immediately to protect the
drive.
 Motor thermal protection
The control program features two separate motor temperature monitoring
functions. The temperature data sources and warning/trip limits can be set up
independently for each function.
The motor temperature can be monitored using
• the motor thermal protection model (estimated temperature derived
internally inside the drive), or
• sensors installed in the windings. This will result in a more accurate motor
model.
Motor thermal protection model
The drive calculates the temperature of the motor on the basis of following
assumptions:
1. When power is applied to the drive for the first time, the motor is assumed
to be at ambient temperature (defined by parameter
35.50 Motor ambient