Xylem Aquavar, Instruction Manual

Page: 43 / 172

Earth (grounding) requirements
WARNING:
For operator safety, it is important to ground the frequency converter properly in
accordance with national and local electrical codes as well as instructions contained within
this document. Ground currents are higher than 3.5 mA. Failure to ground the frequency
converter properly could result in death or serious injury.
NOTICE:
It is the responsibility of the user or certified electrical installer to ensure correct
grounding (earthing) of the equipment in accordance with national and local electrical
codes and standards.
• Follow all local and national electrical codes to ground electrical equipment properly.
• Proper protective grounding for equipment with ground currents higher the 3.5 mA
must be established. See the Leakage current (>3.5 mA) section for details.
• A dedicated ground wire is required for input power, motor power and control wiring.
• Use the clamps provided with the equipment for proper ground connections.
• Do not ground one frequency converter to another in a “daisy chain” fashion.
• Keep the ground wire connections as short as possible.
• Using high-strand wire to reduce electrical noise is recommended.
• Follow motor manufacturer wiring requirements.
Leakage current (>3.5 mA)
Follow national and local codes regarding protective earthing of equipment with a
leakage current > 3.5 mA. Frequency converter technology implies high frequency
switching at high power. This will generate a leakage current in the earth connection. A
fault current in the frequency converter at the output power terminals might contain a DC
component which can charge the filter capacitors and cause a transient earth current. The
earth leakage current depends on various system configurations including RFI filtering,
screened motor cables, and frequency converter power.
EN/EC61800–5–1 (Power Drive System Product standard) requires special care if the
leakage current exceeds 3.5 mA. Earth grounding must be reinforced in one of the
following ways:
• Earth ground wire of at least 8 AWG or 10 mm
2
.
• Two separate earth ground wires both complying with the dimensioning rules.
See EN60364–5–54 section 543.7 for further information.
Using GFCIs (RCDs)
Where Ground Fault Circuit Interrupters (GFCIs) and residual current devices (RCDs), also
know as earth leakage circuit breakers (ELCDs), are used, comply with the following:
• Use GFCIs (RCDs) of type B only which are capable of detecting AC and DC currents.
• Use GFCIs (RCDs) with an inrush delay to prevent faults due to transient earth currents.
• Dimension GFCIs (RCDs) according to the system configuration and environmental
considerations.
5.2 Basic electrical connection
This section contains detailed instructions for wiring the frequency converter. The
following tasks are described:
• Wiring the motor to the frequency converter output terminals
• Wiring the AC mains to the frequency converter input terminals
• Connecting control and serial communication wiring
• After power has been applied, checking input and motor power; programming control
terminals for their intended functions
5 Electrical Installation
Aquavar ® Intelligent Pump Controller - 150 HP to 600 HP INSTRUCTION MANUAL 41