Inovance MD500

8 Specifications and Model Selection
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115
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8
MD500 Model
Recommended
Input IEC Cable
(mm
2
)
<1>
Recommended
IEC Ground
Cable
(mm
2
)
Recommended
Output IE
Cable (mm
2
)
Terminal
width (mm)
Screw
Specication
Recommended
Fuse
Bussmann
Pass UL Certication
Recommended
Contactor
Recommended
Breaker
Rated
Current
(A)
MD500
Model
Rated Current
(A)
Rated
Current
(A)
MD500T400G(-L) 2 x (3 x 240) 240 2 x (3 x 240) * M16 1400 170M6017 800 1000
MD500T450G(-L) 2 x (3 x 240) 240 2 x (3 x 240) * M16 1400 170M6017 800 1000
Note
● *Refer to 3.2.3 Main Circuit Terminals and Dimensions in MD500 Series General-Purpose AC Drive
User Manual for recommendations and copper conductor dimensions.
● <1>Chinese laws are applicable. 3 x 10 indicates a three-core cable, and 2 x (3 x 95) indicates two
3-core cables.
● Refer to Chapter 9 Specications and Model Selection in MD500 Series General-Purpose AC Drive
User Manual for other peripherals.
2. Circuit Breaker
Each AC drive produces more than 3.5 mA leakage current. Therefore, it must be grounded.
AC drive generates DC leakage current in protective conductor. In this case, a time-delay B-type breaker must
be used.
When leakage current causes the circuit-breaker to act, you should:
●
Use a circuit-breaker with higher rated action current or a delay-action circuit-breaker.
●
Reduce carrier frequency.
●
Shorten length of the output cable.
●
Increase sensitivity current of circuit-breaker.
●
Recommended residual current circuit-breaker manufacturers are Chint Electric and Schneider.
8.5 Braking Unit
8.5.1 Selection of Resistance of Braking Resistor
The AC drive transfers regenerative energy generated during braking of motor to external braking resistor. Ac-
cording to formula U x U/R = Pb:
●
U refers to braking voltage at system stable braking. (Its value varies with the system. The default braking
voltage of MD500 Series is 760 V. You can set F9-08 to change the value.)
●
Pb refers to braking power.
8.5.2 Selection of Power of Braking Resistor
In theory, power of braking resistor is the same as braking power. But in consideration of de-rating, power of
braking resistor is calculated from the following formula: K × Pr = Pb × D
●
K is about 50%.
●
Pr refers to power of braking resistor.
●
D refers to braking frequency (percentage of regenerative process to whole deceleration).
The following two formulas can be obtained:
K × Pr = Pb × D = (U × U)/(R × D)
Pr = (U × U × D)/(R × K)
The user can calculate braking resistor power.
K is de-rating coefcient of braking resistor. Low K value can ensure that braking resistor does not get over-