Xylem Aquavar, Instruction Manual

Page: 46 / 172

See section General Specifications for correct dimensioning of motor cable cross-section
and length.
Shielding of cables
Avoid installation with twisted shield ends (pigtails). They spoil the shielding effect at
higher frequencies. If it is necessary to break the shield to install a motor isolator or motor
contactor, the shield must be continued at the lowest possible HF impedence.
Connect the motor cable shield to both the de-coupling plate of the adjustable frequency
drive and to the metal housing of the motor.
Make the shield connections with the largest possible surface area (cable clamp). This is
done by using the supplied installation devices within the adjustable frequency drive.
Cable-length and cross-section
The adjustable frequency drive has been EMC tested with a given length of cable. Keep
the motor cable as short as possible to reduce the noise level and leakage currents.
Switching frequency
When adjustable frequency drives are used together with sine-wave filters to reduce the
acoustic noise from a motor, the switching frequency must be set according to the
instructions in par. 14–01 Switching Frequency.
Terminal
number
96 97 98 99 Description
U V W PE
1)
Motor voltage 0–100% of AC line voltage.
3 wires out of motor
U1
W2
V1
U2
W1
V2
PE
1)
Delta-connected
6 wires
U1 V1 W1 PE
1)
Star-connected U2, V2, W2
U2, V2 and W2 to be interconnected separately
1)
Protected ground connection
Note: In motors without phase insulation paper or other insulation reinforcement suitable
for operation with voltage supply (such as an adjustable frequency drive), fit a sine-wave
filter on the output of the adjustable frequency drive.
Figure 50: Motor connections
5 Electrical Installation
44 Aquavar ® Intelligent Pump Controller - 150 HP to 600 HP INSTRUCTION MANUAL