EQ7 Series Instruction Manual - TECO-Westinghouse Motor Company

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
are used to detect overload conditions of the motor.
Upon detection of overload conditions of the motor, the inverter ceases outputting and issues a motor overload
alarm to protect motor 1.
• Thermal characteristics of the motor specified by F10 and F12 are also used for the overload early
warning. Even if only using 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
1
2
Function
For a general-purpose motor with shaft-driven cooling fan
(The cooling effect will decrease in low frequency operation.)
For an inverter-driven motor, non-ventilated motor, or motor with separately powered cooling
fan
(The cooling effect is constant regardless of the output frequency.)
The figure below shows operating characteristics of the electronic thermal overload protection when F10 = 1. The
characteristic factors 1 through 3 as well as their corresponding switching frequencies f2 and f3 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
HP
Nominal Applied Motor and Characteristic Factors when P99 (Motor 1 selection) = 0 or 4
Thermal time
constant
(Factory default)
Reference current
for setting the
thermal time
constant (Imax)
Output frequency for motor
characteristic factor
Characteristic
factor (%)
f2 f3 1 2 3
0.5, 1
75 85 100
7 Hz
2 to 5 85 85 100
7.5 to 15 5 min
5 Hz 6 Hz 90 95 100
20 Allowable continuous
7 Hz 85 85 100
current
25, 30
150%
5 Hz 92 100 100
40 to 60
Base Base 54 85 95
75 to 125 10 min
frequency frequency 51 95 95
150 or above 33% 83% 53 85 90
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