8
Assembly
fitting the control unit
Fit the control unit to the drive bar or column or to the
machine foot (see the section Device Components).
Connect the MRA 2 motors to the control unit using the
motor cables (1.8 or 3.0 metre lengths).
CAuTIOn!
The MrA 2 must only be installed and
serviced by qualified electricians working
in accordance with current electrical engineering
practices and regulations.
Before you connect or disconnect a motor cable,
you must power down the knitting machine. Wait two
minutes before unplugging the motor cable.
!
Power supply
3 x 400 V AC
PE L1 L2 L3
PE:
yellow/green
L1:
black
L2:
black
L3:
black
Connecting up the step-down trans-
former (optional)
The MRA 2 system operates a rated voltage of 400 V AC.
At input voltages greater than 400 V AC and up to 585
V AC, you must fit a step-down transformer between the
knitting machine and the control unit.
Fit the step-down transformer in the electrical cabinet
or on the machine foot.
585 V
530 V
485 V
440 V
585 V
530 V
485 V
440 V
585 V
530 V
485 V
440 V
Power supply from knitting machine
3 x 440 - 585 V, 50/60 Hz
Power supply for the control unit
3 x 400 V, 50/60 Hz
fitting the capacitor batteries (optional)
In the event of a mains power failure, knitting machines
continue to run on for some time. In the event of a power
failure, a MRA 2 system without capacitor batteries will
stop the yarn feed immediately and this could cause yarn
breakage.
On an MRA 2 system with capacitor batteries, the capacitor
batteries will continue to power the MRA 2 system until
the knitting machine has come to a complete standstill.
The number of capacitor batteries required depends
on a variety of factors and can only be decided on site.
The factors influencing the number of batteries required
includes: machine speeds; rotating mass (open wide knit-
ting machines); general condition of the knitting machine;
number of MRA 2 motors fitted; motor power required;
yarn sensitivity.
Fit the capacitor batteries to the machine foot and
connect them to the control unit (see the control unit
terminal connection diagram).
