Protecting The Relay Output Contact And Attenuating Disturbances In Case Of Inductive Loads; Residual Current Device (Rcd) Compatibility; Selecting The Control Cables - ABB ACS350 User Manual

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Protecting the relay output contact and attenuating disturbances in case
of inductive loads
Inductive loads (relays, contactors, motors) cause voltage transients when switched
off.
Equip inductive loads with noise attenuating circuits [varistors, RC filters (AC) or
diodes (DC)] in order to minimize the EMC emission at switch-off. If not suppressed,
the disturbances may connect capacitively or inductively to other conductors in the
control cable and form a risk of malfunction in other parts of the system.
Install the protective component as close to the inductive load as possible. Do not
install protective components at the I/O terminal block.

Residual current device (RCD) compatibility

ACS350-01x drives are suitable to be used with residual current devices of Type A,
ACS350-03x drives with residual current devices of Type B. For ACS350-03x drives,
other measures for protection in case of direct or indirect contact, such as separation
from the environment by double or reinforced insulation or isolation from the supply
system by a transformer, can also be applied.

Selecting the control cables

All analog control cables and the cable used for the frequency input must be
shielded.
Use a double-shielded twisted pair cable (Figure a, e.g. JAMAK by NK Cables) for
analog signals. Employ one individually shielded pair for each signal. Do not use
common return for different analog signals.
Planning electrical installation
Varistor
230 VAC
RC filter
230 VAC
Diode
24 VDC
Drive
relay
output
Drive
relay
output
Drive
relay
output