•
Terminate each segment at both ends, using
either the termination switch (S801) of the
frequency converter or a biased termination
resistor network.
•
Always use screened twisted pair (STP) cable for
bus cabling.
•
Always follow good common installation practice.
Low-impedance ground connection of the screen at every
node is important, including at high frequencies.
•
Connect a large surface of the screen to ground,
for example with a cable clamp or a conductive
cable gland. It may be necessary to apply
potential-equalizing cables to maintain the same
ground potential throughout the network. Partic-
ularly in installations with long cables.
•
To prevent impedance mismatch, always use the
same type of cable throughout the entire
network.
•
When connecting a motor to the frequency
converter, always use screened motor cable.
Cable
Screened twisted pair (STP)
Impedance
120 Ω
Max. cable length [m] 1200 (including drop lines)
500 station-to-station
Table 3.5 Cable Information
3.7
Optional Equipment
3.7.1 Load Share Terminals
Load share terminals enable the connection of the DC
circuits of several frequency converters. Load share
terminals are available in IP20 frequency converters and
extend out the top of the frequency converter. A terminal
cover, supplied with the frequency converter, must be
installed to maintain the IP20 rating of the enclosure.
Illustration 3.32 shows both the covered and uncovered
terminals.
Illustration 3.32 Load Share or Regeneration Terminal with
Cover (L) and without Cover (R)
3.7.2 Regeneration Terminals
Regen (regeneration) terminals can be supplied for
applications that have a regenerative load. A regenerative
unit, supplied by a third party, connects to the regen
terminals so that power can be regenerated back onto the
mains, resulting in energy savings. Regen terminals are
available in IP20 frequency converters and extend out the
top of the frequency converter. A terminal cover, supplied
with the frequency converter, must be installed to
maintain the IP20 rating of the enclosure. Illustration 3.32
shows both the covered and uncovered terminals.
3.7.3
Anti-condensation Heater
An anti-condensation heater can be installed inside the
frequency converter to prevent condensation from forming
inside the enclosure when the unit is turned off. The
heater is controlled by customer-supplied 230 V AC. For
best results, operate the heater only when the unit is not
running and turn the heater off when the unit is running.
3.7.4
Brake Chopper
A brake chopper can be supplied for applications that
have a regenerative load. The brake chopper connects to a
brake resistor, which consumes the braking energy,
preventing an overvoltage fault on the DC bus. The
braking chopper is automatically activated when the DC
bus voltage exceeds a specified level, depending on the
nominal voltage of the frequency converter.
3.7.5
Mains Shield
The mains shield is a Lexan cover installed inside the
enclosure to provide protection according to VBG-4
accident-prevention requirements.
3.7.6
Mains Disconnect
The disconnect option is available in both varieties of
option cabinets. The position of the disconnect changes
based on the size of the options cabinet and whether or
not other options are present. Table 3.6 provides more
detail about which disconnects are used.
Voltage [V] Frequency converter
model
Disconnect manufacturer
and type
380–500 V N110T5–N160T4 ABB OT400U03
N200T5–N315T4 ABB OT600U03
525–690
N75KT7–N160T7 ABB OT400U03
N200T7–N400T7 ABB OT600U03
Table 3.6 Mains Disconnect Types
Installation
Operating Instructions
34 Danfoss A/S © Rev. 06/2014 All rights reserved. MG16D302
33
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