In this article, we will be looking at the basic parameterization of an FR-D700 VFD for a motor applied to an application that requires a constant torque operation.

For this operation – the VFD will also be set up to allow for 3 predefined control speeds to be applied. As such – the VFD will be operated in external mode.

VFD Selection Process

As should be clear by now, the motor kW is not a sufficient element for the selection process of the suitable VFD, and in fact, is not even fractured. 
The two things required for the selection of a suitable and stand VFD  – is:

  1. The applicaiton details
  2. The motor nameplate details (voltage and FLA)

We already know that this application is a constant torque application. Herewith the motor Nameplate. details. 

Now – referring to the Detailed Instruction manual – we select the following VFD (via the process indicated below)

Basic Parameterization:

The following is a basic breakdown of the type of parameterization to be applied vs their functionality\purpose:(A guideline)

Note that if you are switching 24Vdc (Source) Instead of 0Vdc (Sink), then the wire connected to SD must move to PC, and the jumper must be moved to source.

The parameterization to be set:

Basic Parameterization – The details

Giving the specifics of the parameterization to be set – based on the application and the motor nameplate:

                Pr.0 = Torque Boost (leave as default)

                Pr.1 = Maximum Frequency = 50Hz

                Pr.2 = Minimum Frequency = 0Hz

                Pr.3 = Base Frequency – Motor Nameplate Frequency (usually 50Hz)

Pr.4 = Multispeed Setting (High Speed) – Use only if RH is wired.  = 50Hz

Pr.5 = Multispeed Setting (Medium Speed) – Use only if RM is wired. = 30Hz

Pr.6 = Multispeed Setting (Low Speed) – Use only if RL is wired. = 15Hz

Pr.7 = Acceleration Time (Time to reach maximum speed)  = 5 – 10s

                                If this value is too low – the inverter can trip on Thermal Overload.

Pr.8 = Deceleration Time (Time to reach minimum speed) = 5 – 10s

                                If this value is too low – the inverter can trip on Thermal Overload.

Pr.9 = Electronic Thermal O\L Relay (Rated Inverter Output Current) Motor Name Plate Current = 3.7A

Pr.14 = Load Pattern Selection = 0 (constant torque) (Depends on the application

                Pr.19 = Base Frequency Voltage Motor Nameplate Voltage (Voltage measured by Multimeter)

                Pr.79 = Operation Mode Selection = 0

                                (the Key here is to ensure that the VFD is in EXT Mode for operation.

Please note that these parameters are only the quick start parameters – to allow the inverter to drive the motor safely. For higher control philosophies more parameterization would be required.

Reference and Information Resources

The following is an applicable set of information Resources: