Vacon 100 HVAC, Applications Manual

Page: 153 / 201

P3.9.5 RESPONSE TO OUTPUT PHASE FAULT (ID 702)
Use this parameter to select the response of the drive to an 'Output Phase' fault.
If the measurement of the motor current detects that there is no current in 1 motor phase,
an output phase fault occurs.
See P3.9.2 for more information.
10.9.1 MOTOR THERMAL PROTECTIONS
The motor thermal protection prevents the motor from becoming too hot.
The AC drive can supply a current that is higher than the nominal current. The high current
can be necessary to the load, and it must be used. In these conditions, there is a risk of a
thermal overload. Low frequencies have a higher risk. At low frequencies, the cooling effect
and the capacity of the motor decrease. If the motor has an external fan, the load reduction
at low frequencies is small.
The motor thermal protection is based on calculations. The protection function uses the
output current of the drive to know what is the load on the motor. If the control board is not
energised, the calculations are reset.
To adjust the thermal protection of the motor, use the parameters from P3.9.6 to P3.9.10.
The thermal current I
T
tells the load current above which the motor is overloaded. This
current limit is a function of the output frequency.
NOTE!
If you use long motor cables (max. 100 m) with small drives (≤1.5 kW), the motor
current that the drive measures can be much higher than the actual motor current.
It is because there are capacitive currents in the motor cable.
CAUTION!
Make sure that the airflow to the motor is not blocked. If the airflow is blocked, the
function does not protect the motor, and the motor can become too hot. This can
cause damage to the motor.
P3.9.6 MOTOR THERMAL PROTECTION (ID 704)
Use this parameter to select the response of the drive to a 'Motor Overtemperature' fault.
If the motor thermal protection function detects that the temperature of the motor is too
high, a motor overtemperature fault occurs.
P3.9.7 MOTOR AMBIENT TEMPERATURE FACTOR (ID 705)
Use this parameter to set the ambient temperature where the motor is installed.
The temperature value is given in celsius or fahrenheit degrees.
P3.9.8 MOTOR THERMAL ZERO SPEED COOLING (ID 706)
Use this parameter to set the cooling factor at 0 speed in relation to the point where the
motor operates at nominal speed without external cooling.
When the speed is 0, this function calculates the cooling factor in relation to the point where
the motor operates at a nominal speed without external cooling.
PARAMETER DESCRIPTIONS VACON · 153
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