ERICO TSG Series Surge Reduction Filters (TSG-RSF) - Manual (Page 7)

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Installation Cautions
• Harmonic voltages may also be present in
distribution systems that do not feature
generators. This is normally where non-
linear loads are used, such as UPSs, recti-
fiers, switch-mode power supplies and
motor speed controls. The harmonic volt-
ages may have peak voltages in excess of
the protective clamping voltages, causing
problems such as excessive heat build up.
Because the harmonic waveforms contain
higher order frequencies, capacitive leak-
age currents may increase to above
prescribed limits and shorten the life of
the SRF. It should be noted that in sites
with large harmonic voltage distortion, the
SRF capacitance may dramatically affect
the power factor.
• Seek the manufacturer’s advice before
installing any SRF into a circuit which
features a total harmonic voltage ratio
above 5%.
• With large transients, significant energy
may be passed by the SRF diverters back
to the source or to earth. This may, under
some circumstances, cause upstream earth
leakage circuit breakers or residual current
devices (ELCBs & RCDs) to nuisance trip.
Where possible, these devices should be
installed after the SRF in order to reduce
this possibility.
• Transient protection devices often have
minimum requirements for upstream
fusing to ensure proper operation. See
Section 6.1 for fusing requirements.
• By-pass switches are not recommended
to be used with SRFs as they compromise
the protection offered. The connection of
the by-pass switch compromises the input
to output separation requirement by
bringing the SRF input and output wiring
into close proximity at the switch. Due
to the high reliability of the SRF and,
provided that spare fuses are on hand (for
SRFs of 125A and larger), it is deemed to
be unnecessary to provide a means by
which to bypass the SRF. If these situations
cannot be avoided, contact your local
ERICO
® office to assess the possibility of a
special design.
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