Protections; Motor Thermal Protections - Honeywell HVAC400x Applications Manual

HVAC400X – APPLICATION MANUAL
10.9

Protections

P3.9.1 RESPONSE TO Analog INPUT LOW FAULT (ID 700)
You can use this parameter to select the response of the drive to an 'AI Low' fault.
If the analog input signal becomes less than 50% of the minimum signal for 500ms, an AI Low fault occurs.
P3.9.2 RESPONSE (IF AN ACTION IS SELECTED IN P3.9.1) TO EXTERNAL FAULT (ID 701)
You can use this parameter to select the response of the drive to an 'External fault'.
If a fault occurs, the drive can show a notification of it on the display of the drive. An external fault is activated with
a digital input signal. The default digital input is DI3. You can also program the response data into a relay output.
P3.9.3 INPUT PHASE FAULT (ID 730)
You can use this parameter to select the supply phase configuration of the drive.
NOTE: If you use the 1-phase supply, the value of this parameter must be set to 1-phase support.
P3.9.4 UNDERVOLTAGE FAULT (ID 727)
You can use this parameter to select if undervoltage faults are saved to the fault history or not.
P3.9.5 RESPONSE TO OUTPUT PHASE FAULT (ID 702)
You can 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 HVAC drive can supply a current that is higher than the nominal current. However, the high current can be
required by the application, in which case it must be used. Under 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 the load on the motor is. If the control board is not energized, 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 IT 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 (≤ 2.0 hp)), the motor current that
the drive measures can be much higher than the actual motor current. This 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)
You can use this parameter to select the response of the drive to a 'Motor Overtemperature' fault.
EN2B-0417GE51 R0719 126