Control Techniques FXM5, User Manual

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FXM5 User Guide
7
Issue Number: 5 www.controltechniques.com
3.6 Power connections
3.6.1 AC supply connections
Using an alternative AC supply
The AC supply applied to terminals L1 and L3 supplies the following:
• Field winding of the motor (through the thyristor bridge)
• Power supply for the control-circuits
The AC supply voltage must be in the range specified in Data on page 3 for the control-
circuits power supply. If the voltage is less than 220V ±10%, the control-circuits power
supply must be supplied by an alternative AC supply having an acceptable voltage. Use
the following procedure:
1. Remove fuses FS1 and FS2 from the printed-circuit board in order to ensure
isolation between the alternative AC supply and the field-winding AC supply.
2. Connect the alternative AC supply to terminals E1 and E3. Ensure that the
alternative supply is connected so that the voltage applied to E1 is in phase with the
voltage applied to L1.
3. Ensure that both connections of the alternative supply are protected with 500mA
fuses.
If the voltage rating of the field is much lower than the supply voltage it is
advisable to use a transformer to reduce the supply voltage. This maximises the
resolution of the controller and prevents the possibility of excessive voltage being
applied to the field winding.
Figure 3-3 Connecting an alternative AC supply in phase with the field-winding
supply
Terminal Function Notes
A1
A2
Armature-voltage input
A1 - Positive
A2 - Negative
(With forward rotation)
F1
F2
Field-winding output
F1 - Positive
F2 - Negative
L1
L3
AC supply See AC supply connections
E1
E3
Alternative AC supply See AC supply connections
NOTE