Eurotherm Drives 584S, Product Manual, Page: 58 / 176

CHAPTER 3 - INSTALLATION PROCEDURE
3-16 584S FREQUENCY INVERTER
- If the proceeding is not possible, then the RF earth bond between the filter and 584S/620 drive module is
usefully improved by making an additional RF earth connection using wire braid of at least 10 mm
2
cross
sectional area (due to skin effect).
- For wall mount application, ensure that the cable between the EMC filter and the 584S/620 drive module
cable is passed through conduit mounted between the filter and the Gland Box. This cable must be as
short as possible and segregated from all other cables. The conduit must be electrically connected to the
filter and drive module gland box.
NOTE: M etal surfaces such as eloxized or yellow chromed e.g. with cable mounting or 35 mm DIN rails, screws
and bolts have a high RF impedance which can be very detrimental for EMC performance.
Care should be taken to ensure that the protective earth (PE) conductor exiting from the filter is connected to the
protective earth connection of the 584S/620 drive module. Any additional RF earth such as a cable screen
is not a
protective earth . The EMC filter must be permanently earthed to prevent the risk of electric shock under
abnormal operating instances (such as the loss of one phase of the AC supply). Permanent earthing can be achieved
by either:
- Using a copper protective earth conductor of at least 10 mm
2
or
- Installing a second conductor in parallel connection with the protective conductor to a separate protective
earth terminal.
Each conductor shall on its own meet the requirements for a protective earth conductor. On all recommended
underfloor EMC filters two protective earth connections are provided for permanent earthing.
The recommended EMC filters are designed to operate from normal three-phases supplies which are balanced with
respect to earth (earth referenced supplies). This minimises the earth leakage current due to the filter capacitors
between phase and earth. On some specific customer sites the supply may not be balanced with respect to earth (non-
earth referenced supplies). The earth leakage currents would increase and interfere with the operation of any earth-
fault monitoring equipment. In addition the EMC performance of the filter will be degraded. Eurotherm Drives do
not recommend the use of AC supply filters on non earth-referenced supplies.
With all AC and servo drives conducted and radiated interference increases with the inverter switching
frequency. The emissions can therefore be reduced by selecting the lowest acceptable switching frequency.
(584S switchable option only). Thermal conformance of the recommended filters is only guaranteed up to a
given switching frequency. For the 584S types 4, 5, 6 and 7 this is 6kHz, all with a maximum equivalent
cable length of 150m.
As with all power electronic drives the conducted emissions increase with motor cable length. EMC
conformance to the stringent limits is only guaranteed up to a cable length of 50 m (types 4, 5, 6 and 7). This
length can be increased. Refer to section entitled Motor Cable-length Limitations in this chapter.
If one EMC filter is to be used in an enclosure, then this filter should be mounted as close to the incoming AC
supply to the enclosure as possible.
IMPORTANT
WARNINGS !
The recommended EMC filters are designed to work with supplies which are balanced with respect
to earth (i.e. earthed referenced supplies). On some specific customer sites the supply may not be
balanced with respect to earth. The recommended standard EMC filters are not recommended be
used on such supplies. Refer to Eurotherm Drives for more information.
The EMC filters contain capacitors phase-to-phase and phase-to-earth. Discharge resistors are
fitted, but the filters, terminals and wiring must not be touched for a period of 5 minutes after the
removal of the AC supply.
Not adhering to this warning can result in electric shock.
The EMC filter must only be used with a permanent earth connection using one of the following
alternatives:
a) Using a copper protective earth conductor of at least 10 mm
2
or
) b) Installing a second conductor in parallel with the protective conductor to a separate
protective earth terminal on the filter or inverter. The conductor on its own shall meet the
requirements for a protective earth conductor.
Thermal performance of the EMC filter is only guaranteed up to a switching frequency of 6 kHz
(type 4, 5, 6 and 7), and a maximum equivalent cable length of 150 m.
Refer to the following section regarding safety considerations with earth-fault detection systems.
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