Xylem IM131R01 AQUAVAR AV II - Manual (Page 91)

• Use a shielded motor cable which is grounded over a large surface area at both ends. The
shield on this cable should be uninterrupted. If a shielded motor cable cannot be used, the
unshielded motor line should be laid in a metal conduit or duct which is uninterrupted and
grounded at both ends.
• When selecting shielded cable for use as motor leads, it is important to select a cable which is
designed for operation at the frequencies and power levels involved. Improper selection of
motor cable can cause high potential to exist on the shield. This could cause damage to the
inverter and other equipment and could pose a safety hazard.
• The following cables are acceptable for this purpose: OLFlex Series 150CY, 110CY, 110CS,
100CY, 100CS and 540CP. Siemens CordaflexSM is also acceptable. Some of these cables are
VDE-approved only; others carry VDE, UL, CSA and combinations of these ratings. Be sure to
confirm that the cable you are using meets the certification of the agency required.
• OLFlex cables are available from OLFlex Wire & Cable, 30 Plymouth Street, Fairfield, NJ 07004,
1-800-774-3539.
• Cordaflex cables are available from Siemens Energy and Automation, Inc., Power Cables, 3333
State Bridge Road, Atlanta, GA 30202, 1-800-777-3539.
• If the installation requires the use of an output reactor, the reactor, like the line filter, should be
placed a close as possible to the inverter.
• Control wires longer than 3 feet (1 meter) must be run in shielded cable and the shield must be
terminated at common (CM) on the inverter. Note that connection to CM, the circuit common,
rather than earth ground, is allowed because X2C inverters have isolated control inputs. If the
signal run exceeds 30 feet (9 meters), a 0-2- mA or 4-20 mA signal should be used, as it will
have better noise immunity than a low level voltage.
• Other loads connected to the power source may produce voltage transients (spikes) that may
interfere with or damage the inverter. Line reactors or filters can be used on the input power to
protect the inverter from such transients.
• If the inverter is operated from switchgear devices or is in close proximity to switchgear devices
(in a common cabinet), the following procedures are recommended as a precaution to prevent
these devices from interfering with the inverter’s operation:
• Wire the coils of DC devices with freewheeling diodes. The diodes should be placed
as close as possible to the physical coil of the device.
• Wire the coils of AC devices with RC type snubber networks. Place the snubbers as
close as possible to the physical coil of the device.
• Use shielded cables on all control and monitoring signals.
• Route distribution cables (for example, power and contactor circuits) separately and
as far away from control and monitoring signal cables as possible.
Appendix C
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