Fuji Electric FRENIC-MEGA, Инструкция по эксплуатации

Страница: 168 / 358

5-49
F10 to F12 Electronic Thermal Overload Protection for Motor 1
(Select motor characteristics, Overload detection level, and Thermal time constant)
F10 through F12 specify the thermal characteristics of the motor for its electronic thermal overload protection that is used to
detect overload conditions of the motor.
Upon detection of overload conditions of the motor, the inverter shuts down its output and issues a motor overload alarm
0l1
to protect motor 1.
• Thermal characteristics of the motor specified by F10 and F12 are also used for the overload early warning.
Even if you need only the overload early warning, set these characteristics data to these function codes. (Refer to
the description of E34.)
• For motors with PTC thermistor, connecting the PTC thermistor to the terminal [V2] enables the motor overheat
protective function. For details, refer to the description of H26.
„ Select motor characteristics (F10)
F10 selects the cooling mechanism of the motor--shaft-driven or separately powered cooling fan.
Data for F10 Function
1
For a general-purpose motor with shaft-driven cooling fan
(The cooling effect will decrease in low frequency operation.)
2
For an inverter-driven motor, non-ventilated motor, or motor with separately powered cooling fan
(The cooling effect will be kept constant regardless of the output frequency.)
The figure below shows operating characteristics of the electronic thermal overload protection when F10 = 1. The
characteristic factors
α
1 through
α
3 as well as their corresponding switching frequencies f
2
and f
3
vary with the
characteristics of the motor. The tables below list the factors of the motor selected by P99 (Motor 1 Selection).
Cooling Characteristics of Motor with Shaft-driven Cooling Fan
Nominal Applied Motor and Characteristic Factors when P99 (Motor 1 selection) = 0 or 4
Nominal applied
motor
HP
Thermal time
constant
τ
(Factory default)
Reference current
for setting the
thermal time
constant (Imax)
Output frequency for motor
characteristic factor
Characteristic
factor (%)
f
2
f
3
α
1
α
2
α
3
0.5, 1
5 min
Allowable
continuous current
×
150%
5 Hz
7 Hz
75 85 100
2 to 5 85 85 100
7.5 to 15 6 Hz 90 95 100
20 7 Hz 85 85 100
25, 30 5 Hz 92 100 100
40 to 60
10 min
Base frequency
×
33%
Base frequency
×
83%
54 85 95
75 to 125 51 95 95
150 or above 53 85 90