HAZARDOUS VOLTAGES EXIST
WITHIN THE TSG-SRF ENCLOSURE.
THIS UNIT SHOULD BE INSTALLED
AND SERVICED ONLY BY QUALIFIED
PERSONNEL AND IN ACCORDANCE
WITH RELEVANT NATIONAL
ELECTRICAL AND SAFETY CODES.
ALL INSTRUCTIONS MUST BE
FOLLOWED TO ENSURE CORRECT
AND SAFE OPERATION OF THE SRF.
2. WARNINGS
• PRIOR TO INSTALLATION. Ensure that the
TSG-SRF is of the correct voltage, current,
phasing, and frequency, and is of the type
recommended by the manufacturer for the
equipment and power distribution system
in use.
• DO NOT MEGGER. This unit contains
over-voltage protection components.
• TSG-SRFs contain capacitors. Disconnect
power at least 1 minute prior to removing
the escutcheon panel. Check voltage prior
to working on SRF internals.
•
TSG-SRFs must be connected to a low
impedance earth (<10Ω) for correct operation.
WARNING
ERICO products shall be installed and used only as indicated in ERICO’s product instruction sheets and training materials. Instruction sheets
are available at www.erico.com and from your ERICO customer service representative. Improper installation, misuse, misapplication or
other failure to completely follow ERICO’s instructions and warnings may cause product malfunction, property damage, serious bodily
injury and death.
WARRANTY
ERICO products are warranted to be free from defects in material and workmanship at the time of shipment. NO OTHER WARRANTY,
WHETHER EXPRESS OR IMPLIED (INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE), SHALL
EXIST IN CONNECTION WITH THE SALE OR USE OF ANY ERICO PRODUCTS. Claims for errors, shortages, defects or nonconformities ascertainable upon inspection must be made in writing within 5 days after Buyer's receipt of products. All other claims must be made in writing
to ERICO within 6 months from the date of shipment or transport. Products claimed to be nonconforming or defective must, upon ERICO's
prior written approval in accordance with its standard terms and procedures governing returns, promptly be returned to ERICO for inspection. Claims not made as provided above and within the applicable time period will be barred. ERICO shall in no event be responsible if the
products have not been stored or used in accordance with its specifications and recommended procedures. ERICO will, at its option, either
repair or replace nonconforming or defective products for which it is responsible or return the purchase price to the Buyer. THE FOREGOING STATES BUYER’S EXCLUSIVE REMEDY FOR ANY BREACH OF ERICO WARRANTY AND FOR ANY CLAIM, WHETHER SOUNDING IN CONTRACT, TORT OR NEGLIGENCE, FOR LOSS OR INJURY CAUSED BY THE SALE OR USE OF ANY PRODUCT.
LIMITATION OF LIABILITY
ERICO excludes all liability except such liability that is directly attributable to the willful or gross negligence of ERICO's employees. Should
ERICO be held liable its liability shall in no event exceed the total purchase price under the contract. ERICO SHALL IN NO EVENT BE
RESPONSIBLE FOR ANY LOSS OF BUSINESS OR PROFITS, DOWNTIME OR DELAY, LABOR, REPAIR OR MATERIAL COSTS OR ANY SIMILAR OR
DISSIMILAR CONSEQUENTIAL LOSS OR DAMAGE INCURRED BY BUYER.
with ALL relevant national electrical and
safety codes.
• The power supply to the TSG-SRF should
always be turned off (and locked) before the
escutcheon panel is removed for any purpose.
Internal circuit breakers do not fully isolate
the filter.
• Check all TSG-SRF terminals for tight
connections. (Some terminals may become
loose during transport)
• Ensure all input and output cabling, once
installed, is tightened to the correct torque
settings (see Table 3, Page 16).
• Do not disconnect upstream Earth or Neutral
connections supplying the SRF while power
is still applied, as this may damage the SRF
or load.
• No combustible items should be stored
within the SRF during operation.
• Do not leave this manual behind the
escutcheon panel after applying power to the
SRF. Retain this manual for future reference.
• Failure to heed instructions or warnings may
result in personnel injury, equipment damage
or ineffective transient protection.
The CRITEC®Triggered Spark Gap Surge
Reduction Filter (TSG-SRF) from ERICO
rates high energy clamping devices and special
filtering circuitry. TSG-SRFs are installed in series
with the circuit, usually at the point of entry to
the building or structure. They are available in
single or three-phase configurations for load
currents from 40A to 2000A per phase.
The purpose of a TSG-SRF is to filter and
protect against lightning induced transients.
The SRF provides a clean, filtered supply of
electricity to all output connected equipment
when installed in accordance with the
manufacturer’s instructions.
Protection is achieved via a three-stage circuit.
This includes the internal CRITEC Triggered
Spark Gap unit as the primary surge diverter,
a purpose designed low pass filter network
®
incorpo-
and a secondary, Transient Discriminating (TD)
diversion stage to further clamp the transient
energy to safe levels. This allows the TSG-SRF
to:
• Provide filtering to the clamped waveform
in order to reduce the rate of voltage rise.
• Provide a secondary stage of surge diversion to protect equipment from transients
which may be induced onto the SRF out
put cables or be caused by the load itself.
The use of this combination of technologies
has resulted from considerable advances in
technology which have negated previous
disadvantages associated with spark gaps.
The use of spark gaps has not been practical
in the past due to the high initiation voltages
required to activate such devices and also
their poor follow-current performance.
4
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Introduction
Both issues have been addressed with the
®
CRITEC
TSG, a spark gap surge diverter
incorporating a triggering device which
enables the TSG to operate on much lower
voltages than was previously possible.
Additionally, the TSG is able to extinguish the
spark and return to the peak mains voltage
as soon as the transient event has passed,
thereby greatly improving follow-current
performance.
These considerable technological advances
mean that the TSG can be utilised as the
primary shunt diverter within the new SRF,
exploiting the performance benefits of spark
gap diverters.
Incorporating TSG technology into a surge
reduction filter has allowed a fundamental
breakthrough in the overall design of the
filter. Ferrite cored inductors, which are
much smaller than non-saturating air-cored
inductors required in MOV based surge
reduction filters have been used in the
CRITEC SRF.
The combination of TSG and TD technology
provides the benefits of high surge capability,
low let through voltage and considerably
reduced dv/dt. This applies to both surge
performance and over-voltage withstand from
short and long duration high-energy surges.
TD technology has been developed
specifically for abnormal over-voltage
conditions that may occur on sites with
poor voltage regulation, or due to wiring or
distribution faults. TD and TSG technologies
feature an extremely high over-voltage
withstand. This eliminates heat build up that
can occur with standard technologies when
the protection devices start to clamp on the
peak of each abnormal mains cycle.
Traditional MOV technology is not suitable in
applications where sustained over-voltage
conditions can be experienced. The range of
CRITEC TSG-SRFs, with a higher abnormal
over-voltage withstand, are preferred in these
environments.
The use of ferrite-cored inductors is possible
because the let-through voltage from a TSG
remains high for only a few microseconds
(μs). In comparison, the let-through voltage
from a MOV based device remains at
anywhere between 600V and 1000V for the
duration of the surge. This time can range
from 30μs to 400μs and above for longer
tail pulses and determines how much energy
the inductor has to store before reaching
saturation and becoming ineffective.
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5
Installation Cautions
3. INSTALLATION CAUTIONS
CAUTIONS:
• Transient protection devices are usually
rated to protect against non-repetitive
pulses from sources such as direct or
induced lightning energy.
• They are not designed to provide
protection against repeated cyclic
anomalies such as those caused by
motor speed control notching (variable
speed controls, etc.).
• SRFs are not designed to provide
protection against sustained over-voltage
conditions where the supply voltage
exceeds, for an extended period of time,
the nominal rating of the protection
equipment (continuous over-voltages
from poorly regulated generators or
distribution systems, for example).
• Smaller power generation equipment does
not always conform to the same standards
of voltage regulation that is in place for
mains power reticulation. A large number
of smaller or cheaper generators have a
voltage waveform that approximates
240Vrms (often poorly regulated), but
more importantly, which often contains
significant higher order harmonics and
may exhibit a peak voltage on each
half cycle far in excess of the normal
340V (peak). Such machines are usually
capacitive excitation induction generators,
as opposed to synchronous generators.
The problem is usually increased when
the generator is lightly loaded.
Figure 1. Seek specialist advice with the above installations.
6
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Installation Cautions
• Harmonic voltages may also be present in
distribution systems that do not feature
generators. This is normally where nonlinear loads are used, such as UPSs, rectifiers, switch-mode power supplies and
motor speed controls. The harmonic voltages 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 leakage 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.
By-pass switches are not recommended
•
to be used with SRFs
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
®
office to assess the possibility of a
ERICO
special design.
as they compromise
• Transient protection devices often have
minimum requirements for upstream
fusing to ensure proper operation. See
Section 6.1 for fusing requirements.
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7
Identify the Distribution System
4. IDENTIFY THE DISTRIBUTION
SYSTEM
A number of different power distribution
systems are employed in various countries
around the world. It is important to identify
the distribution system in use prior to installation of the SRF, and confirm that the SRF is
the model recommended by the manufacturer for that distribution system.
To identify the distribution system in use,
consult reputable and knowledgeable sources
such as:
• The local power supply authority
• Local electrical engineers
• Applicable regulatory bodies or standards
associations
Alternatively, confirm the type of distribution
system used by personal inspection. By visually tracing the neutral and earthing conductors
from the load equipment or sub-distribution
point back to the point of entry (and perhaps
to the supply transformer), the type of distribution system should be identifiable with the
aid of the following diagrams (Figures 2-6).
These are prescribed in local regulations and
describe the relationship between the source,
exposed or conductive parts of the installation and earth. Amongst these, the TN-C,
TN-S, TN-C-S and TT systems are most
commonly encountered. Note that supplies
such as those used in industry and mining
may often use a different distribution system
to that of the local supply authority.
Figure 2. TN-C system: In this system, the neutral and protective earth conductor combine in a single
conductor throughout. All exposed conductive parts are connected to the PEN conductor.
8
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Identify the Distribution System
**
Figure 3. TN-S system: In this system, a separate neutral and protective earth conductor are run
throughout. The protective PE conductor can be the metallic sheath of the power distribution cable or a
separate conductor. All exposed conductive parts of the installation are connected to this PE conductor.
Figure 4. TN-C-S system: In this system, a separate neutral and protective earth functions combine in a
single PEN conductor. This system is also known as a Multiple Earthed (MEN) system and the protective
conductor is referred to as the combined neutral earth (CNE) conductor. The supply PEN conductor is
earthed at a number of points throughout the network and generally as close to the consumer’s point
of entry as possible. All exposed conductive parts are connected to the CNE conductor.
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9
Identify the Distribution System
Figure 5. TT system: A system having one point of the source of energy earthed and the exposed conductive
parts of the installation connected to independent earthed electrodes.
CRITEC TSG-SRFs provide protection for
equipment on TN-C, TN-S, TN-C-S, TT, delta
or split-phase distribution systems when
selected, installed and earthed in the specified manner.
The TSG-SRFs are designed to be used in
distribution systems that provide a separate
earth and neutral connection. TSG-SRFs
should not be used in IT distribution systems.
(Figure 7).
Specialist application advice should be sought
in the protection of delta supplied threephase systems (Figure 8) before the purchase
of the protection equipment.
Figure 6. Split-phase distribution systems.
10
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Identify the Distribution System
Figure 7. IT system: A system having no direct connection between live parts and earth, but having all
exposed conductive parts of the installation connected to independent earthed electrodes. CRITEC Surge
Reduction Filters should NOT be used in IT systems without advice from a specialist.
The diagrams are provided as a guide to
identifying and distinguishing the distribution
system in use. Metering, over-current protection, and other details have not been shown.
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As electrical wiring and safety regulations
differ from country to country, it is important
to ensure that the installation complies with
all regulations applicable to the location.
Please seek further assistance if uncertain.
Figure 8. Delta connected three-phase systems.
Although delta connected systems are “IT”
systems, special mention is made due to their
frequent use in mining and industrial applications.
Standard CRITEC
be suitable for some applications.
11
®
Surge Reduction filters may not
Mounting the Surge Reduction Filter
5. MOUNTING THE SRF
Before mounting the SRF, refer to Table 4
(weights and dimensions on last page of this
manual) which provides dimensions and unit
weights. Ensure that appropriate lifting
equipment is used when installing the larger
SRFs. When installing the SRF, consideration
should be given to future service needs.
Ensure that a clear view of the status
indicators is provided. The SRFs should be
mounted away from other electrical
apparatus (300 mm minimum) and in a
position that avoids close proximity to
combustible materials.
TSG-SRFs of 630A capacity and smaller are
designed to be wall mounted. Mounting
brackets (as shown in Figure 9) are supplied.
Larger units are anchored through holes
provided in the rear of the SRF enclosure.
The cabling and upstream over-current
protection requirements and all instructions
provided in this manual, should be taken into
consideration before mounting the SRF.
• To preserve the IP rating, TSG-SRF units
from 40A to 200A must be installed in
accordance with Figure 9 and Section 6.2.
• Larger SRF units from, 400A to 2000A
are ventilated and should be mounted in
a dust and moisture-free, ventilated
environment.
• All TSG-SRFs should be installed in a dry,
well-ventilated area. Avoid sites subject to
moisture ingress.
• SRFs are not intended for use in harsh or
corrosive environments.
Where the SRF is to be enclosed in a
switchboard cubicle, models are available
without the proprietary enclosure. These
backplane units are denoted by the model
number suffix ’BP’.
Figure 9. Typical mounting arrangement for wall
mounted CRITEC
®
Surge reduction Filters (40-200A).
12
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Optimising Performance/Fusing
6. OPTIMISING PERFORMANCE
The protection equipment must be
earthed and installed in accordance with
all relevant national electrical and safety
standards. The term "point of entry" protec-
tion, is a general descriptive concept of zonal
boundary protection, as detailed in standards
such as IEC 1024. Some local wiring regulations will allow the protection equipment to
be mounted directly at the point of entry,
while other countries require protection
equipment to be installed after the metering
or main circuit isolators or over-current
protection.
The following installation points
require attention to ensure that optimal
protection is provided by the protection
equipment. This information is provided
as a guide only. Compliance with local
electrical and safety regulations must be
ensured.
6.1 FUSING
Over-current and short-circuit protection must
be provided in order to protect the SRF and
associated wiring if a fault develops. The
over-current protection should be installed in
such a manner as to provide a means of
isolating the SRF from the mains supply. This
is an important safety consideration. Over-
current protection provided within the
SRF is not designed to act as a means of
isolation. Over-current protection within the
SRF does not necessarily isolate all TSG-SRF
components.
Table 1 summarises the minimum requirements for upstream fusing or circuit breakers
required to prevent nuisance tripping, or
operation of fusing when the TSG activates.
Upstream fusing and cabling may need
to be of higher capacity than the appearance or size of filter would suggest.
Fusing of smaller capacity may experience
occasional nuisance tripping during surge and
transient conditions.
Max supplyTypical supplyMinimum Minimum
fault transformer circuitfuse size
currentratingbreaker
10kA500A100A40A
15kA750A100A63A
20kA1000A125A80A
43kA2000A160A100A
Table 1.
The table above summarises the minimum
requirements for upstream fusing or circuit
breakers necessary to prevent nuisance
tripping or operation of fusing when the
TSG primary surge diverter activates.
To allow the TSG, (the internal primary diverter) to operate correctly, it is essential that the
minimum requirements for upstream fusing
or circuit breakers be adhered to.
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13
Cabling
6.2 CABLING
The cabling and earth wires connected to the
filter input should always be run separately,
with a minimum clearance of 300 mm
between them and all other cables or sensitive equipment (as shown in Figure 11). The
input cable and earth wire will carry the transient energy, while the "protected" output
cable can be considered to be a "clean
filtered" supply.
By separating these cables, any incoming
transients will not be induced from the input
cables onto nearby "clean" cables. This clearance will reduce the possibility of arc-over
from input to output cables. Where cables
need to run closer together due to space
restrictions, input and output cables should
cross at right angles and not be installed
parallel to each other. Cabling should be
sized in accordance with all relevant wiring
standards to ensure that the full load current
can be safely supplied. All cabling or busbars
connected to the protection equipment
should be securely anchored to prevent
undue stress being applied to the
input/output terminals.
• Cable glands (of an appropriate design)
must be used for all input and output
cables to preserve the IP rating of the
40A - 200A TSG SRFs.
• To protect input and output cabling
insulation from sharp edges around the
cable entry knockouts, suitable cable
glands or grommets must be installed.
An alternative is to extend the cable
conduit through the knockout.
Input and output terminal requirements are
detailed in Table 2.
Cable terminal torque requirements are
detailed in Table 3.
14
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Cabling
Figure 10. Identification of SRF input and output terminals.
Figure 11. Maintaining clearance between input and other cabling.
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15
Cabling
Filter RatingMaximum Accepted Cable Size
Phases(s)NeutralEarth
Termination SizeTermination SizeTermination Size
MethodMethodMethod
Single Phase
40AInputScrew Clamp50 mm
2
Screw Clamp50 mm
OutputScrew Clamp35 mm2Screw Clamp35 mm
63AInput Screw Clamp50 mm
OutputScrew Clamp35 mm
2
Screw Clamp50 mm
2
Screw Clamp35 mm
125AInputStud8 mmStud8 mmStud*8 mm
OutputStud8 mmStud8 mmStud*8 mm
Three-Phase
2
40AInputScrew Clamp50 mm
OutputScrew Clamp35 mm
63AInputScrew Clamp50 mm2Screw Clamp50 mm
OutputScrew Clamp35 mm
Screw Clamp50 mm
2
Screw Clamp35 mm
2
Screw Clamp35 mm
125AInputBolt8 mmBolt8 mmStud8 mm
OutputBolt8 mmBolt8 mmStud8 mm
200AInputBolt10 mmBolt10 mmStud8 mm
OutputBolt10 mmBolt10 mmStud8 mm
400AInputBolt10 mmBolt10 mmStud8 mm
OutputBolt10 mmBolt10 mmStud8 mm
630AInput6 x Bolt10 mm6 x Bolt10 mmStud8 mm
Output6 x Bolt10 mm6 x Bolt10 mmStud8 mm
1250AInput6 x Bolt 12 mm6 x Bolt12 mm2 x Stud8 mm
Output6 x Bolt12 mm6 x Bolt12 mm2 x Stud8 mm
2000AInput6 x Bolt12 mm 6 x Bolt12 mm2 x Stud8 mm
Output6 x Bolt12 mm6 x Bolt12 mm2 x Stud8 mm
Table 2. Termination details for TSG-SRFs.
* Input and output earths on 40 and 63A TSG-SRFs use a common earth stud.
M1017.0 Nm (12.5 ft.lbs)all locations except as above
Table 3. Recommended tightening torques.
16
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Output Distribution
6.3 OUTPUT DISTRIBUTION
As the output of the SRF is considered to
be a "clean filtered" supply it should not
be subjected to situations where further
transients can be introduced. The "clean"
supply should not be run external to the
facility, for example to provide power to an
external building or tower lighting. From the
aspect of transient protection, to do so would
create possible "points of entry" for transient
energy to the protected zone.
A similar scenario exists where the output of
the SRF is fed to an electrically "noisy" load.
Any transients developed by this load may
also be fed to other equipment connected to
the same supply.
Electrically noisy equipment should ideally be
supplied from a separate SRF and all cabling
should be run in isolation to other cables.
Figure 12. Connection of circuits outside
the protected zone.
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Figure 13. Isolation of sensitive equipment from
noisy sources.
17
Earthing
6.4 EARTHING
The earths for all site equipment should
be integrated (preferably deploying a single
point earthing approach) and an
equipotential earth plane should be created.
Integral to this is the elimination of earth
loops. It is common, but incorrect from the
point of lightning protection, for there to be
separate earths for various services, for example electricity mains, telephone, computer
equipment and other building services.
For sites where the interconnection of these
earths is difficult, either for practical or
regulatory reasons, the use of a Transient
Earth Clamp (TEC) is recommended. The TEC
behaves as an open circuit under normal
operation, but under surge conditions it
activates to effectively clamp individual
points together.
The effectiveness of an SRF is intimately
related to the impedance presented by the
earthing system to which it is connected. A
low impedance route to the earth is required
(less than 10Ω). This can be achieved by
ensuring that the earth electrode system
at the site presents a low surge impedance
with respect to the ground. Additionally, the
interconnecting cabling must be of adequate
cross sectional area and be routed to provide
as short and direct a path as is practical.
Ideally the earthing system impedance should
be measured using a meter which simulates
the typical wave shape of a lightning
transient. ERICO
®
can provide this service.
The earth conductor for the SRF should be
sized according to local regulations but with
a minimum size of 6 mm
2
. Every attempt
should be made to limit the cable length to
under 5 metres.
By selecting the most direct route, with the
minimum possible number of bends to the
earth point or internal earth bar, the risk of
side flashing and excessive voltage rise across
the equipment is reduced. Figure 14 depicts
the correct earthing concept as described
above.
Figure 14. Preferred approach
to equipotential bonding.
18
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Connection of Alarm Circuits
6.5 CONNECTION OF ALARM
CIRCUITS
The TSG-SRF secondary surge diverters are
continuously monitored and their internal
protection status is identified by a two
segment LED indicator for each phase.
Reduction in surge handling capacity activates
a set of voltage free alarm contacts which
can be used to shut down the load or to
activate an external warning. Once an alarm
situation is registered, there is a three-second
delay prior to the alarm contacts opening.
This three-second alarm delay is provided to
eliminate the possibility of nuisance alarms
that may be attributed to brief supply voltage
variations.
When mains voltage is applied to the
TSG-SRF and the surge diverters are fully
functional, the alarm contacts will be in the
energised or normal state. The NC contact
will be in short circuit with the COM contact.
Should the surge handling capacity fall to
below the alarm threshold, these contacts will
be in the de-energised or alarm state and the
NO contact will be in short circuit with the
COM contact.
The contacts are "Fail-Safe" in that, if power
to the unit fails, the contacts will revert to the
de-energised or alarm state.
The alarm contacts should only be connected
by an appropriately qualified person owing to
the possibility of mains voltage being present
in the TSG-SRF cabinet. Care should be taken
to route the alarm wiring away from the
input circuit and any other current-carrying
conductors.
Alarm contact ratings:
• 2A @ 30Vdc
• 600mA @ 110Vdc
• 600mA @ 125Vac
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19
Installation Arrangement for Australian MEN Systems
6.6 INSTALLATION
ARRANGEMENT FOR
AUSTRALIAN MEN SYSTEMS
Under Australian Standards classification,
SRFs are considered a piece of equipment
to be connected to the mains supply. They
are not intended for use as switchboards,
distribution boards or other equipment. As
these devices are classified as "electrical
equipment" AS 3000 Wiring Regulations
apply to the installation and operation of
the units.
AS 3000 specifies minimum requirements for
electrical equipment that is connected to
switch boards or distribution boards.
For a point of entry application in the multiple earth neutral (MEN) distribution system,
the SRF equipment should be installed as
close as possible after the MEN point and
after both the main disconnect switch/overcurrent protector and any metering equipment. The SRF therefore, may not be installed
at the physical "point of entry" of the mains
power to the building. It must be earthed
and installed in accordance with all other
applicable electrical and safety standards. As
the protection equipment is hardwired, the
installation must be inspected by an appropriately authorized electrical authority official
prior to commissioning.
Figure 15. Typical connection detail for SRF
point of entry installation in MEN system.
20
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TSG-SRFs on Sub-Circuits
6.7 TSG-SRFs ON SUB-CIRCUITS
Where SRFs are installed to protect
equipment on a particular sub-circuit, it
is strongly recommended that additional
protection be installed at the power point of
entry. Primary shunt protection at the point of
entry should be used to divert the peak surge
currents away from the sub-circuit. This will
reduce the risk of cross-coupling of transients
onto adjacent circuits and will reduce the risk
of flashover between the locally grounded
chassis and the earth circuit.
Figure 16 details the role of point of entry
protection in these instances. The cables
supplying the input to the SRF and the
connection to the earthing system will carry
a proportion of the surge energy which has
been let through the primary point-of-entry
protector.
Care should be taken therefore, in the
routing of these cables to ensure that this
energy will not couple onto adjacent circuits.
Figure 16. Operation of primary shunt protection
and SRFs on sub-circuit.
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21
TSG-SRFs on Sub-Circuits
In some instances it will be necessary to
provide a separate earth electrode for the SRF
(subject to compliance with relevant wiring
regulations), particularly where the filter is to
be installed on a sub-circuit some distance
from the existing earth electrode. In this
instance, the new electrode should be located
as near as possible to the SRF. This secondary
electrode must be electrically bonded to the
existing earthing system via the most direct
route possible, using flat copper tape and
should be buried to an appropriate depth.
This earthing arrangement is depicted in
Figure 17. If a secondary earth cannot be
installed, or the earth impedance through the
sub-circuit to the earth is significantly above
10Ω, special care must be taken. The risk of
flashover between the locally grounded
chassis and the earth circuit may exist.
Careful attention must be paid to equipotential
bonding of the protected equipment.
Figure 17. Earthing of an SRF remote from MEN point. (Subject to compliance with relevant
national standards). Care is needed to avoid earth loops within protected environment.
22
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Servicing & Trouble Shooting
7. SERVICING and TROUBLE
SHOOTING
HAZARDOUS VOLTAGES EXIST
WITHIN THE SRF ENCLOSURE. THE
SRF SHOULD ONLY BE SERVICED BY
QUALIFIED PERSONNEL, IN ACCORDANCE WITH RELEVANT NATIONAL
ELECTRICAL AND SAFETY CODES.
Do not disconnect upstream earth or neutral
connections supplying the TSG-SRF while
power is applied to the unit, as this may
damage the TSG-SRF or load.
Only replace the primary TSG or secondary
TDS surge diverters with an identical type.
Voltage-free alarm contacts are activated
(after a three-second delay) should the
secondary protection status fall below a
pre-determined level.
Fault Checks
All indicators, alarms and surge counters
(where fitted) should be checked on a regular
basis.
Should any of the display indicators fail to
illuminate, check for the following conditions:
• Is power available to the TSG-SRF?
• Check the input voltage by measuring the
voltage between active and neutral.
• Has the line fuse blown or upstream circuit
breaker or fuse tripped?
Surge reduction filters of 1250A capacity and
above, have fuses installed in series with the
TSG primary surge protection.
If these fuses are open circuited for any
reason, or if the fuse ruptures, then the
primary surge protection is removed from
circuit.
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• For SRFs utilising input fuses, spares of
the correct type and rating should be
held on site.
The TSG-SRFs are essentially maintenance
free, although periodic inspection is recommended to ensure that the ventilation louvres
(where fitted) do not become clogged with
dust. In high humidity areas, dust should be
regularly vacuumed from the enclosures to
prevent the possibility of voltage tracking.
Indicators
If power is being supplied to the TSG-SRF and
the indicators still fail to illuminate, then it is
possible that either the primary TSG or
secondary TDS devices have exhausted their
surge capacity. In such circumstances, the
particular devices should be replaced as a
matter of urgency as they are no longer
providing optimum protection.
A single status indicator is provided on each
TSG surge diverter to indicate the surge
capacity of the primary TSG surge diverter(s).
When power is applied and full surge capacity is available, the status indicator will be illuminated. Should the indicator fail to
illuminate, the TSG should be replaced,
as optimum protection is no longer
provided. It should be noted that the status
indicator will not illuminate (regardless of TSG
surge capacity) if power is not available.
The TSG-SRF employs TD technology as the
secondary protection stage on both single
and three-phase models. The integrity and
surge capacity of this stage is indicated by a
two-segment LED display per phase, located
on the escutcheon panel of the TSG-SRF.
Should one or both of the secondary stage
LED indicators fail to illuminate
a reduction
in surge handling capacity has occurred.
In this event the affected surge diverter
module should be
replaced.
Non-Standard Products & Accessories
8. NON-STANDARD PRODUCTS
& ACCESSORIES
This document details the installation
procedure for our current range of standard
TSG-SRFs. Non-standard units are also
manufactured to suit specific customer
requirements. This manual is likely also to
be supplied with these units. The following
are details for some of the non-standard
variations and options available.
Backplane unit:
Normally denoted by ‘BP’ in the model
number. These units are supplied without
the proprietary enclosure and are intended
to be mounted in a customer provided
switchboard.
Low Voltage unit:
This is an alternative voltage version of
the standard TSG-SRF. This unit incorporates
primary and secondary surge diverters
specifically designed for low voltage
applications (110/120VAC).
Surge Counter:
Optional surge counter (available for the
TSG-SRF three-phase 125A to 2000A models).
Benefits of having the surge counter installed
are accurate and reliable monitoring of
surge activity and predictive maintenance
scheduling. Accidental erasure of the surge
count is prevented by the use of a
non-resetable counter display.
The surge counter can be either factory or
field installed. The ordering information for
this option is detailed below.
• Factory installed - Add the following
postscript to the part number of the
product. (TSG-SRF3125 /SC for a threephase 125A Surge Reduction Filter with
factory installed surge counter)
Figure 18. Backplane unit, supplied for
installation into customer provided switchboard.
• Field installed - Order a TDS-SC from your
®
nearest ERICO
office or distributor. When
installing the TDS-SC, please follow the
upgrade installation instructions which
are provided with the counter.
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Schmetic Diagrams
9. SCHEMATIC DIAGRAMS
A
C1
Figure 19. Schematic diagram
for Single-Phase Filters.
Figure 20. Schematic diagram
for Three-Phase Filters.
Indicative mass only. If exact mass is critical for these
*
units, contact ERICO
®
for confirmation.
Table 4. Physical dimensions of CRITEC®TSG-SRFs
26
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Surge Reduction Filters form an
important part of a much larger
lightning, surge and transient protection
philosophy. From over 150 years of
combined aggregate experience in the
field, ERICO
the Six Point Plan of Protection.
®
engineers have developed
Power Protection Device
Communications Line Protection device
• Coaxial Surge Protection device
• Telecommunications Line Protector (TLP)
• Data Line Protector (DLP)
• Data Equipment Protector
The ERICO Six Point Plan of Protection
Capture the lightning
1
strike.
Convey this
2
energy to ground.
Dissipate energy
3
into the grounding
system.
The range of TSG-SRFs fulfill some of the requirements of point 5 of the plan.
Careful consideration of each of the six interdependent disciplines of the Six point
Plan is important to help ensure the provision of optimal protection and long-term
operational viability. The degree of protection required will be determined by the
individual situation and the proper application of risk management principles.