Taco SKV SelfSensing

Taco® SKV
13
302-365, Effective: June 5, 2017
© 2017 Taco, Inc.
• Use the clamps provided with on the equipment for
proper ground connections.
• Do not ground one adjustable frequency drive to
another in a “daisy chain” fashion.
• Keep the ground wire connections as short as possi-
ble.
• Use of high-strand wire to reduce electrical noise is
recommended.
• Follow the motor manufacturer wiring requirements.
8.3.1 Leakage Current (>3.5 mA)
Follow national and local codes regarding protective
grounding of equipment with a leakage current > 3.5 mA.
Adjustable frequency drive technology implies high fre-
quency switching at high power. This will generate a leak-
age current in the ground connection. A fault current in
the adjustable frequency drive at the output power termi-
nals might contain a DC component which can charge
the filter capacitors and cause a transient ground
current. The ground leakage current depends on
various system con"gurations including RFI filtering,
shielded motor cables, and adjustable frequency drive
power.
EN/IEC61800-5-1 (Power Drive System Product Stan-
dard)
requires special care if the leakage current exceeds
3.5mA.
Grounding must be reinforced in one of the following
ways:
• Ground wire of at least 0.0155 in2 [10mm2]
• Two separate ground wires both complying with the
dimensioning rules
See EN/IEC61800-5-1 and EN50178 for further informa-
tion.
8.3.2 Using RCDs
Where residual current devices (RCDs), also known as
ground leakage circuit breakers (ELCBs), are used, com-
ply with the following:
• Use RCDs of type B only which are capable of
detecting AC and DC currents
• Use RCDs with an inrush delay to prevent faults due
to transient ground currents
• Dimension RCDs according to the system configura-
tion and environmental considerations
8.3.3 Grounding Using Shielded Cable
Grounding clamps are provided for motor wiring (see
Figure 8-6).
Figure 8-6:
Grounding with Shielded Cable
8.3.4 Grounding Using Conduit
DANGER: GROUNDING HAZARD! Do not
use conduit connected to the adjustable fre-
quency drive as a replacement for proper
grounding. Ground currents are higher than
3.5 mA. Improper grounding can result in
personal injury or electrical shorts.
Dedicated grounding clamps are provided (See Figure 8-
7).
Figure 8-7: Grounding with Conduit
1.Use a wire stripper to remove the insulation for
proper grounding.
2.Secure the grounding clamp to the stripped portion
of the wire with the screws provided.
3.Secure the grounding wire to the grounding clamp
provided.