Control Techniques Midi-Maestro User Manual

Midi-Maestro and Maxi Maestro Drive
6
Transformer power rating
A single three-phase transformer may be able to
supply more than one Drive.
The power rating of the secondary winding must
exceed the nominal power rating of the motor.
When using a transformer with more than one
secondary winding, the power rating of the primary
must exceed the sum of the power ratings of the
secondary windings.
The secondary windings must be delta-connected.
(This is not essential for the primary winding.)
Control Techniques Ltd is able to supply
the appropriate transformers.
Three-phase AC supply
To calculate the necessary adjustments required for
each secondary winding, the following equation for Ps
(in
VA) must be used:
(())
(())
Ps = Paz 1.5××××
++
173
2
.
n
Where:
Paz =
{(Vm1 × Cm1) + (Vm2 × Cm2) + (Vmn × Cmn)}
Vm =
Maximum motor speed in rads/sec =
RPM/9.55
Cm = Nominal motor torque in Nm
(())
1.73
n+2
=
Corrective factor when using more than one Drive
in parallel
n = Number of Drives
To calculate the total transformer power in
VA, use the
following equation:
P
t
= P
S1
+ P
S2
+ ...P
Sn
Where:
P
S1
= Power rating of secondary winding 1
P
S2
= Power rating of secondary winding 2
P
Sn
= Power rating of secondary winding n
Ext Drive braking resistor
Ext Drive braking resistor
L3(Phase 3)
L2(Phase 2) AC supply
L1(Phase 1)
Earth (Ground)
-DC
20
21
22
23
24
25
Power connector
19
20
18
17
16
M2
M1
+DC
Figure 7 Three-phase AC supply and ground
connections
Single-phase AC supply
Model DCD 140 × 8/16 may be operated on a
single-phase supply.
The transformer power rating may be calculated using
the equation:
(())
(())
Ps = Paz 1.5××××
++
173
2
.
n
Where:
Paz =
{(Vm1 × Cm1)+(Vm2 × Cm2) + (Vmn × Cmn)}
Vm =
Maximum motor speed in rads÷sec =
RPM÷9.55
Cm = Nominal motor torque in Nm
(())
1.73
n+2
=
Corrective factor when using more than one Drive
in parallel
n = Number of Drives.
The secondary winding should be connected to pins 21
and 22 of the power connector.
Ext Drive braking resistor
L3(Phase 3)
L2(Phase 2) AC supply
L1(Phase 1)
Earth (Ground)
-DC
20
21
22
23
24
Power connector
19
20
18
17
16
M2
M1
+DC
Figure 8 Single-phase AC supply and ground
connections

Control Techniques Midi-Maestro Specifications

General

Brand	Control Techniques
Model	Midi-Maestro
Category	DC Drives
Language	English