Base Frequency (Pr. 3); Multi-Speed Settings (Pr. 4 To Pr. 6) - Mitsubishi Electric FR-A800 Series Beginner's Manual

Parameter
6.2.3

Base frequency (Pr. 3)

The setting of parameter 3 is very important because it matches the frequency inverter's output to the
requirements of the motor.
Parameter 3 specifies the output frequency at which the output voltage is set to its maximum value.
This is normally set to the rated frequency of the motor, which can be found on the motor's rating
plate. Be careful with this parameter – incorrect settings can cause overload states and lead to auto-
matic shutdown of the inverter.
You can set the inverter's maximum output voltage with parameter 19, which should be set to the
maximum output voltage allowed for the motor (this can be found on the motor's rating plate).
6.2.4

Multi-speed settings (Pr. 4 to Pr. 6)

A limited number of preset speeds is quite adequate for many applications. This can be achieved with-
out the need for analog setpoint signals. Instead, you enter fixed setpoint values in these parameters
and activate them with ON/OFF signals applied to the inverter's terminals.
All the inverters described in this guide allow selection of up to 15 frequency setpoint values (corre-
sponding to 15 speeds) via terminals RH, RM, RL and REX. The inverter must be in external operation
mode for this to be possible, of course.
The first three frequency settings are entered in parameters 4 through 6. Further fixed speed settings
(4 to 15) can be stored in additional parameters. See your frequency inverter's documentation for fur-
ther details.
Frequency Inverters - Beginner's Guide
100 %
0
Output frequency (Hz)
Speed settings
The simple mode parameters in detail
Parameter 3 defines the ratio between
the output voltage and the output fre-
quency (V/f pattern).
Example for connection of the inverter's
RH, RM, RL and REX terminals (in source
logic).
The frequency (speed) settings can be se-
lected with relay output signals from a
programmable logic controller (PLC).
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