4
The layout of the power terminals and connections is shown in FIG 1.
L N
U V W
-B +B
3~
M
PE
1p
h
a
se
2
3
0
V
/5
0
H
z
Braking unit
(option)
N
FIG 1
5.1.2. Recommended protection devices installed upstream of the drive and cabling
Drive model
FIA-L
18
37
55
75
110
150
220
250
fuse ratings*
6A
10A
16A
20A 25A
cable size (for 3-core)** mm
2
1,5
2,5
4,0
*
The use of slow protection devices (curve C) is recommended because a current surge may appear at power on.
**
Cable sizes are recommendations only. Cabling should conform to local codes of practice and
regulations.
5.1.3. Motor connection
•
No protection devices between the drive and the motor are recommended. The power connections
from the drive output to the motor may be switched, for isolation purposes
;
but not for control
purposes.
•
Connection between the drive and the motor as short as possible are recommended to prevent
emissions from the motor cable.
If it is not possible, screened or armoured cable may be used . The screen or armour should be
connected in the same way as for standard cable (to both the motor earth terminal and the drive
earth terminal).
•
Installations with long cable runs to the motor (i.e. above approx. 30 m), may need the addition of
motor line chokes to prevent nuisance tripping of the drive caused by capacitative leakage effects.
Output voltage of the drive FRECON FIA - L : 3 x 230 V !
MOTOR WINDING CONNECTION MUST BE COMPATIBLE WITH THIS VOLTAGE !
IN THE MOST CASES : DELTA CONNECTION
5.2. Motor speed
•
Standard squirrel-cage ac induction motors are designed as single speed machines. If it is intended
to use the capability of the drive to run the motor at speeds above its designed maximum, it is
strongly recommended that the motor manufacturer is consulted first.
•
The principal risks due to overspeeding are the destruction of the rotor by centrifugal force, or of the
bearings by vibration or heat.
•
Low speed is liable to result in overheating of the motor because the effectiveness of the internal
cooling fan reduces in proportion to the square of the reduction of speed. Motors should be
equipped with thermistor protection, and if full benefit of the use of low speeds is to be gained from
a variable speed drive it may be necessary to arrange additional cooling for the motor.
