Mitsubishi Electric FR-A700 Series, Technical Manual

Page: 397 / 550

431
PARAMETER
2
P
ARAM
ETE
R
(3) PWM carrier frequency automatic
reduction function [ Pr. 260 ]
When [ Pr. 260 = 1 ] (initial value in ) in
, performing continuous operation at
the 85% or more of the rated inverter current with the
inverter carrier frequency set to 3kHz or more ([
Pr. 72
3 ]) will automatically reduce the carrier frequency
to 2kHz to protect the inverter output transistor.
(Although the motor acoustic noises increase, it is not
a fault.)
When [
Pr. 260
=0] (initial value in ) in
, the carrier frequency is constant (at
the [ Pr.72 ] setting) regardless of the load, making
the motor sound uniform. For , make sure to
operate continuously at less than 85% of the inverter
rated current when carrier frequency is set 3kHz or
more (less than the rated output current in
parenthesis on page 4) for keeping the carrier
frequency constant.
2.20.9 Cooling fan operation selection [Pr. 244]
(common
)
The operation of built-in cooling fan (in forced cooling inverters) can be controlled. (To confirm which inverters are forced
cooling, refer to the specification list on page 2 .)
In either of the following cases, fan operation is regarded
as faulty, [FN] is shown on the operation panel, and the fan
fault (FAN) and alarm (LF) signals are output.
• [When Pr. 244 = 0 ]
When the fan comes to a stop with power ON.
• When [ Pr. 244 = 1 ]
For the terminal used for FAN signal output, set 25
(positive logic) or 125 (negative logic) in any of [
Pr. 190 to
Pr. 196 Output terminal function selection ], and for the LF
signal, set 98 (positive logic) or 198 (negative logic).
F700 D700
F700
F700 D700
D700
F700 D700
F700
Carrier frequency automatic reduction
characteristics
Carrier
frequency
[kHz]
2
14.5
85% Current
When
[ Pr. 72 = 5]
100%
[When 55K or less]
5
2
6
85% 100%
3
4
Carrier
frequency
[Hz]
Current
When
[ Pr. 72 = 3]
[When 75K or more]
F700 D700
common
[Pr. ] Name Initial Value Setting Range Description
244
Cooling fan operation
selection
1
0
Operates in power-ON status.
Cooling fan ON/OFF control invalid (the cooling fan is always
on at power on)
1
Cooling fan ON/OFF control valid
The fan is always ON while the inverter is running. During a
stop, the inverter status is monitored and the fan switches ON-
OFF according to the temperature.
When the inverter is running and the fan stops
during fan ON command.