Mini Maestro User Guide 15
Issue Number: 5 www.controltechniques.com
Reservoir capacitors
Use the following equation to calculate the total required value of reservoir capacitance:
C = (Pt ÷ V2) x 2000 µF
The factor 2000 allows for regeneration current during braking.
The factor can be reduced to 1000 when all of the following conditions apply:
V2 = 24V to 45V
Maximum motor speed = 1500 RPM
Three-phase AC supply is used
System inertia is less than the motor inertia
.Discharge resistor
The discharge resistor ensures the reservoir capacitors are discharged in 10 seconds
when the AC supply is disconnected from the drive.
Use the following equation to calculate the required value: R = 20 ÷ C
Use the following equation to calculate the power rating: P = [V2]
2
÷ R
AC supply fuses
Delayed action fuses should be connected in the primary and secondary circuits of the
transformer.
Use the following equations to calculate the ratings of the fuses:
DC supply fuses
A 12.5A fast-action fuse is fitted in the fuse holder on the panel of the installation kit.
This protects the DC supply to the drive. If necessary, replace this fuse with a 16A fast-
action fuse. Refer to the following table:
If the green drive normal LED on the drive becomes unlit (even temporarily) when the
motor is being decelerated, this indicates overvoltage protection is occurring. To prevent
this occurrence, increase the value of reservoir capacitance
NOTE
Correct fuse protection must be used to avoid fire risk.
WARNING
Number of phases Primary fuses Secondary fuses
1 1.3 x Pt ÷ (VAC + 1) Frm 1.6 x Pt ÷ V1 Fsm
3 0.75 x Pt ÷ (VAC + 1) Frt Pt ÷ V1 Fst
DCD60x3/6 DCD60x7/14 DCD60x10/20 DCD60x14/28
12.5A 12.5A 16A 16A
To Next Page
Loading...
