Proteção contra arco elétrico - Integração entre o sistema de monitoramento TVOC-2 e os disjuntores em caixa aberta Emax

Protection against electric arc Integration between Arc Guard System TM   (TVOC-2) and Emax air-circuit breakers White paper

ABB |  Arc Guard System™ 1 Protection against electric arc Integration between Arc Guard System TM  (TVOC-2)  and Emax air-circuit breakers Index 1. Introduction .................................................................... 2 2. The electric arc ............................................................... 3   2.1. Electric arc phenomenon .......................................... 3  2.2. Effects of the electric arc inside switchgear     and controlgear assemblies ...................................... 3   2.3. Effects of the electric arc on human beings ............... 4 3. Assemblies equipped with devices limiting internal  arc effects (active protection concept)  ............................. 5 4. Application example ...................................................... 14 

2  Arc Guard System™ | ABB 1. Introduction In the last years a lot of users have underlined the question of safety in electrical assemblies with reference to one of the most severe and destructive electro-physical phenomenon: the electric arc.Such phenomenon generates internal overpressures and re-sults in local overheatings which may cause high mechanical and thermal stresses in the equipment.  Arc accidents can happen due to several reasons, such as human mistakes, bad connections, animals etc. Most of-ten the accident occurs when someone is working in the switchgear for maintenance or installation. This is normally performed with an open cabinet door. Since the cabinet door is open the protection of arc-proof switchgear design will be significantly decreased. The arc guard system is therefore a  natural part of a modern switchgear design.  Luckily accidents are quite unusual, but when they happen the consequences are often severe, resulting in heavy injuries or death. This is many times combined with long downtimes and destroyed equipment. For this reason it is crucial to build up a robust safety solution that works every time.   The purpose of this document is giving the necessary expla-nations for the correct use and proper integration between the new Arc Guard by ABB TVOC-2, a device which can detect an electric arc thanks to the optical sensors, and ABB SACE circuit-breakers.This document is not aimed at dealing with the concept of internal arc-proof assemblies but at describing an active pro-tection system used to limit the effects of the internal arc.

ABB |  Arc Guard System™ 3 2. The electric arc 2.1 Electric arc phenomenon The electric arc is a phenomenon that takes place as a consequence of a discharge. This occurs when the voltage between two points exceeds the insulating strength limit of the interposed gas. In the presence of suitable conditions, a plasma is generated which carries the electric current till the opening of the protective device on the supply side. Gases, which are good insulating means under normal conditions, may become current conductors in consequence of a change in their chemical-physical properties due to a temperature rise or to other external factors. To understand how an electric arc originates, reference can be made to what happens when a circuit opens or closes. During the opening phase of an electric circuit the contacts of the protective device start to separate thus offering to the current a gradually decreasing section; therefore the current meets growing resistance with a consequent rise in the temperature. As soon as the contacts start to separate, the electric field applied to the circuit exceeds the dielectric strength of the air, causing its perforation through a discharge.  The high temperature causes the ionization of the surrounding air which keeps the current circulating in the form of elec-tric arc. Besides thermal ionization, there is also an electron emission from the cathode due to thermoionic effect. The ions, formed in the gas and by collision due to the very high temperature, are accelerated by the electric field, strike the cathode, release energy in the collision thus causing a local-ized heating which generates electron emission. The electric arc lasts till the voltage at its ends supplies the energy sufficient to compensate for the quantity of heat dissi-pated and to maintain the suitable conditions of temperature. If the arc is elongated and cooled, the conditions necessary for its maintenance lack and it extinguishes. Analogously, an arc may originate also as a consequence of a short-circuit be-tween phases. A short-circuit is a low impedance connection between two conductors at different voltages. The conduct-ing element which constitutes the low impedance connec-tion (e.g. a metallic tool forgotten on the busbars inside the enclosure, a wrong wiring or a body of an animal entered into the enclosure), is subject to the difference of potential and is passed through by a current of generally high value, depend-ing on the characteristics of the circuit.  The flow of the high fault current causes the overheating of the cables or of the circuit busbars, up to the melting of the conductors of the lower section. As soon as a conductor melts, conditions occur that are similar to those present dur-ing the circuit opening. At that point an arc starts which lasts either till the protection devices intervene or till the conditions  necessary for its stability subsist. The electric arc results are characterized by an intense ionization of the gaseous means, by reduced drop of the anodic and cathodic voltage (10 V and 40 V respectively), and by high or very high current density in the middle of the column (of the order of 10 2 -10 3  up to 10 7  A/ cm 2 ). Also by very high temperatures (thousands of °C) always  in the middle of the current column and – in low voltage - by a distance between the ends variable from some microns to some centimeters. 2.2  Effects of the electric arc inside switchgear and   controlgear assemblies In the proximity of the main boards, i.e. in the proximity of big electrical machines, such as transformers or generators, the short-circuit power is high and consequently also the energy associated with the electric arc due to a fault is high. Without going into complex mathematical descriptions of this phe-nomenon, the first instants of arc formation inside a cubicle can be schematized in 4 phases: 1. compression phase: in this phase the air volume occupied  by the arc is overheated owing to the continuous contribu-tion of energy. Due to convection and radiation the remain-ing volume of air inside the cubicle warms up. Initially there are temperature and pressure values different from one zone to another;

4  Arc Guard System™ | ABB 2. The electric arc 2. expansion phase: from the first instants of internal pressure  increase, a hole is formed through which the overheated air begins to flow out. In this phase the pressure reaches its maximum value and starts to decrease owing to the release of hot air; 3. emission phase: in this phase, due to the continuous con- tribution of energy by the arc, nearly all the air is forced out under a soft and almost constant overpressure; 4. thermal phase: after the expulsion of the air, the tem- perature inside the switchgear reaches almost that of the electric arc. Thus beginning this final phase which lasts till the arc is quenched, when all the metals and the insulat-ing materials coming into contact undergo erosion with production of gases, fumes and molten material particles. Should the electric arc occur in open configurations, some of the described phases could not be present or could have less effect; however, there will be a pressure wave and a rise in the tempera-ture of the zones surrounding the arc.  Here are some data to understand how dangerous it is being in the proximity of an electric arc: • pressure: it has been estimated that at a distance of 60 cm from an electric arc associated with a 20 kA arcing fault a person is subject to a force of 225 kg; moreover, the sudden pressure wave may cause permanent injuries to the eardrum;  • temperature: an electric arc can reach about 7000-8000 °C; • sound: electric arc sound levels can reach 160 db, a shot-gun blast is only 130 db. 2.3 Effects of the electric arc on human beings From the above, it is evident that the electric arc represents a hazard source for people and goods.  The hazards to which a person is exposed due to the release of energy generated by an arc event are:•  inhalation of toxic gases;•  burns;•  injuries due to ejection of materials;•  damages to hearing. Inhalation of toxic gases The fumes produced by burnt insulating materials and by mol-ten or vaporized metals can be toxic. The fumes are caused by incomplete burning and are formed by carbon particles and by other solid substances suspended in the air. Burns The high temperature levels of the gases, produced by the electric arc, and the expulsion of incandescent metal particles may cause more or less severe burns to people. Flames can cause all degrees of burn up to carbonization: the red-hot solid bodies, such as the metal fragments of the assembly involved, cause third degree burns, superheated steam causes burns analogous to those by hot liquids where-as radiant heat generally causes less severe burns. Injuries due to ejection of materials  The ejection of loose parts caused by the electric arc can re-sult in injuries to the most suscetible parts of the human body as, for example, the eyes. The materials expelled owing to the explosion produced by the arc may penetrate the cornea and damage it. The extent of the resulting lesion depends on the characteris-tics and on the kinetic energy of these objects. Moreover, the ocular region can sustain injuries to the mucosa because of the gases released by the arc and the emission of ultraviolet and infrared rays can injure the cornea and the retina depend-ing on the radiation wavelengths. Damages to hearing As already mentioned, the electric arc manifests itself as a real explosion, whose sound may cause permanent injuries to hearing.

ABB |  Arc Guard System™ 5 3. Assemblies equipped with devices limiting internal arc effects  (concept of active protection) Safety for the operator and for the installation in case of arcing inside LV switchgear can be obtained through three different design philosophies:1. assemblies mechanically capable of withstanding the elec- tric arc (passive protection) 2. assemblies equipped with devices limiting the effects of  internal arcing (active protection) 3. assemblies equipped with current limiting circuit-breakers. These three solutions (also combined together) have found a remarkable development in the industrial field and have been successfully applied by the main manufacturers of LV switch-gear and controlgear assemblies. In the following pages we focus on the devices limiting internal arc effects, that are on active protection. However, it must be kept in mind that an active protection, in comparison with a passive one, is intrinsically more complex due to the presence of additional electromechanical/electronic devices which can be subject to faults or tripping failures. With active protection it is meant to guarantee the resistance to internal arcing by installing devices limiting the arc. The possible approaches can be of two types:•  limiting the destructive effects of the arc, once it has oc- curred, by means of overpressure detectors. • limiting the destructive effects of the arc, once it has oc- curred, by means of bright arc detectors (Arc Guard Sys-tem TVOC-2) The first possibility consists in installing in the assembly arc detectors which sense overpressure. As already specified the overpressure wave is one of the other  effects occurring inside an assembly in case of arcing.As a consequence it is possible to install some pressure sen-sors which are able to signal the pressure peak associated with the arc ignition with a delay of about 10 to 15 ms. This signal operates on the supply circuit-breaker without waiting for the trip times of the selectivity protections to elapse, which are necessarily longer.Such a system does not need any electronic processing de-vice, since it acts directly on the shunt opening release of the supply circuit-breaker.Obviously, it is essential that the device is set at fixed trip thresholds. When an established internal overpressure is reached, the arc detector intervenes. However, it is not easy to define in advance the value of over-pressure generated by an arc fault inside a switchboard. The second possibility consists in installing in the assembly, detectors which sense the light flux associated with the elec-tric arc phenomenon (arc detectors).The operating logic of an arc detector is the following: the oc-currence of an arc inside the switchboard is detected by the arc detector because an intense light radiation is associated with this phenomenon. The arcing control system detects the event and sends a tripping signal to the circuit-breaker. In this case the reaction time of the detection is about 1 ms Figure 1 shows the possible installation areas where this device can be positioned inside a switchboard. The ideal solu-tion is to provide the installation with at least one detector for each column, with the consequent reduction to a minimum of the length of the optical fibers carrying the signal. Example showing the position of detectors in:1. Horizontal and vertical bus bar system2. Circuit-breaker cubicle Figure 1 1 2

0.1 kA 1 kA 10 kA 100 kA 1E3 kA 1E-2s 0.1s 1s 10s 100s 1E3s 1E4s E3 E2 E1 E3H 3200 PR123-LSI 3200A E2N 1600 PR122-LSI 1600A E1N 800 PR123-LSIG 800A 6  Arc Guard System™ | ABB 3. Assemblies equipped with devices limiting internal arc effects  (concept of active protection) In cases where the detectors can be expose to an intensive light  (camera flash, direct sunlight etc.), an additional current sensor can be positioned at the incoming of the main circuit-breaker.This unit adds a current condition to the system. In the event of an arc, both the current sensing unit - which detects an “anomalous” current due to the arc fault - as well as the sensor detecting the light radiation associated with the arc enables the system to intervene and allow the consequent opening of the circuit-breaker. Figure 2: current sensing unit The tripping time of this system, which consists mainly of the circuit-breaker and of the unit TVOC-2, is a few milliseconds. It by-passing the tripping of the overcurrent release of the circuit-breaker, which – for example – could be delayed be-cause of different installation necessities, among which:1. selectivity requirement; 2. connections of capacitor banks3. electrical components with high inrush currents. Now let us see in details why it is necessary to delay the trip-ping times in the above mentioned applications. Selectivity requirement One of the techniques used to obtain selectivity between circuit-breakers is to increase progressively the current thresh-olds and the trip delays that are closer to the power supply sources. In this way a given value of short-circuit (or overload) current will make the protections on the supply side trip after a defined time delay. For example, to allow any protection placed closer to the fault to trip, excluding the area of occur-rence of the fault. It is evident that the circuit-breakers on the supply side might have very high setting values for S (delayed short-circuit protection function) in terms of ms, as shown in the following example: It is evident that the circuit-breaker E3, because of the number of circuit-breakers involved in the selectivity chain, shall have the instantaneous protection in OFF position (necessary to get downstream selectivity) and the delayed one relevant to the protection function S set at the maximum possible value (close to 1 second). A1 T1 Q1

Auxiliary supply C11 YO X4 1 X4 2 C12 C11 C11 C12 C12 PE A1 N A2 L1 100=240V AC 100=250V DC 100-240Vac 100-250Vdc 73 74 63 64 K6 Trip 53 54 K5 Trip 43 44 K4 Trip 34 32 K3 Trip 31 24 22 K2 Trip 21 14 12 K1 IPoF 11 or 10s 1E4s 1E3s 100s 1s 1E-2s 0.1kA 1kA 10kA 100kA 1E3kA I3=OFF I S L Time-Current LLL Arc Guard System Emax TVOC-2 + + SOR 60-75 ms 0.1s ABB |  Arc Guard System™ 7 Connection of capacitor banks The devices used for the protection of capacitor banks shall be sized taking into account that at the moment of connection there is an overcurrent at high frequency (in the first instants equivalent to a short-time short-circuit) this amplitude de-pends on the grid parameter on the supply side and on the capacitor bank.For this reason the circuit-breaker, besides having an ade-quate breaking capacity shall have the instantaneous short-circuit protection set at the maximum value or even in OFF with protection S active and set with delayed times. Also in this case, as in that previously analyzed, under short-circuit conditions the tripping time depends on the setting of t2 (trip-ping time of function S). Electrical components with high inrush currents This “category” includes all those electrical devices which to function at the connection instant absorb a current higher than the rated one.As it is easy to understand, in order to avoid unwanted trips during the current absorption, in these cases too the circuit-breaker shall have the instantaneous protection excluded (protection in OFF) and protection S active, thus allowing the machine to start thanks to the delays set. For example, this application typology includes lighting instal-lations (incandescent lamps, fluorescent lamps, etc.) and large-size electrical motors, in which switching-protection and starting operations are managed by Emax CBs equipped with PR122-PR123.Another example is the inrush current absorbed by the LV/LV transformer on the primary side. Such current, which is necessary to magnetize the transformer windings, can reach up to 14 times the rated current. The Arc Guard System detects the arcing event and sends the trip signal to the circuit-breaker. All with trip times of just a few milliseconds, by-passing the trip time of the overcurrent  release for all those applications in which - due to installation requirements – the trip units have delay time settings.  The following Figure shows what above described with the Arc Guard System formed by a circuit-breaker equipped with the shunt opening release (SOR) and TVOC-2: As regards the connection, it is necessary to connect the contact of the TVOC-2 to the terminals (K4) n.43-44 (or, as an alternative, (K5) n.53-54 or (K6) 63-64 in series with the shunt opening release (SOR) of the circuit-breaker (C11-C12 terminals).

8  Arc Guard System™ | ABB To reduce this time (as previously said, the faster the time, the more efficient the system), with PR122/123 for Emax it is pos-sible to use the internal module PR120/K. In fact, the contacts of this module can be configured and customized according to one’s own requirements; in our case it is possible to associ-ate the opening of the circuit-breaker to each 24Vdc signal arriving  to the input contact of the module. This alternative allows the total times to be remarkably re-duced since, in this way, they no longer depend on the shunt opening release (SOR), but on the opening directly command-ed by the electronic unit. As regards the connection between the input contact of the module PR120/K and TVOC-2 reference shall be made to the example of page 15. The following table shows the components and the relevant trip times according to the “technique” used (either with SOR or in case with PR120/K) as from the moment in which the light flux is detected to the moment when the circuit-breaker poles are in open position. Circuit-breaker Trip unit Accessory Arc monitor Total time E1-E6 PR121/PR122/ PR123 SOR TVOC-2 ≈  60-75ms PR122/PR123 PR120K ≈  35-45ms As it can be noticed in the table, it is evident that the solu-tion with the use of the module PR120/K reduces the total trip times and therefore it clearly represents a more efficient solution if compared with the traditional one with SOR (shunt opening release). 3. Assemblies equipped with devices limiting internal arc effects  (concept of active protection) 10s 1E4s 1E3s 100s 1s 1E-2s 0.1kA 1kA 10kA 100kA 1E3kA I3=OFF I S L Time-Current LLL Arc Guard System Emax TVOC-2 + + 0.1s 35-45 ms the opening time depends on:-the size of the circuit-breakers;-the arc fault current.

ABB |  Arc Guard System™ 9 Examples of manageable operation logics TVOC-2 can command up to three different circuit-breakers since it has the possibility of associating a defined number of light sensors to each circuit-breaker. This makes it possible to use the arc monitor in all those ap-plications in which due to different plant engineering reasons, in the event of an arc, it is not sufficient the opening of the main circuit-breaker (or even also of all the three circuit-breakers), but a logic strictly connected to the plant engi-neering configuration is required. The following pages report some examples of these applications trying to describe their operation logics. As indicated in the previous pages, the Arc Guard System remarkably reduces the trip times in the event of an electric  arc, above all by using the input digital contact of the module PR120/K. As a consequence, it is evident that under these conditions it is not possible to obtain selectivity in the event of internal arc even if the arc is on the load side of an outgoing feeder. The following example illustrates the above. Figure 3 shows the trip curves of three circuit-breakers, one on the supply side (QF1) selective with the two outgoing feed-ers (QF2-QF3). As it can be seen, since every light sensor commands the main circuit-breaker, in case of an internal arc, there will be a downtime for the whole plant. Practically, it is as if the circuit-breaker on the supply side had a protection function which would make it instantaneous, thus making all the settings and time delays set according to the selectivity study useless. 60-75 ms 10s 1E4s 1E3s 100s 1s 1E-2s 0.1kA 1kA 10kA 100kA 1E3kA Time-Current LLL 0.1s 1E5s QF3 QF2 QF1 LOAD 1 LOAD 2 open QF1 QF2 QF3 QF1: open LOAD 1 and LOAD 2 not supplied Figure 3

10  Arc Guard System™ | ABB In order to bypass such problem, when selectivity represents a fundamental aspect also under electric arcing conditions, it is possible to “exploit” the capacity to command up to three circuit-breakers through a single TVOC-2. This is done by assigning to each light sensor the task of opening one of the three of them; in this way the system is selective also in the  event of an electric arc on the load side of an outgoing feeder (in the example on the load side of QF2). The following figure illustrates the above (to simplify the exam-ple only 5 light sensors of the 30 available have been repre-sented). 3. Assemblies equipped with devices limiting internal arc effects  (concept of active protection) It is evident that in order to get a selective system, each light sensor must not be influenced by the light fluxes which do not affect its area; in order to do so it is necessary that between the sensors some obstacles are present (typically the metal enclosure of the cubicles) as shown in the figure. Furthermore, the light sensors must be positioned in a “strategic” way (after a thorough analysis and not accidentally) to define the interest areas and the operating zones. This is made easier also by the fact that we are considering large power distribu-tion switchboards in which the internal dimensions and the metalwork structure are such as to allow the separation of the sensors according to their relevant operating areas. QF1 QF2 QF3 60-75 ms 10s 1E4s 1E3s 100s 1s 1E-2s 0.1kA 1kA 10kA 100kA 1E3kA Time-Current LLL 0.1s 1E5s QF2 QF1 LOAD 1 LOAD 2 open QF3 QF1 and QF3 closed: LOAD 2 supplied QF2 opened X3X2X1

ABB |  Arc Guard System™ 11 From an operational point of view: To set this function on the arc monitor TVOC-2 it is necessary to position correctly the dip switches positioned on the left side of the arc monitor as shown in the following figure: In this way, the TVOC-2 will make the circuit-breakers QF1-QF2-QF3 trip as follows: For each light signal detected by a light sensor belonging to the row of X1 detectors, TVOC 2 will command the tripping of QF1 circuit-breaker only For each light signal detected by a light sensor belonging to the row of X2 detectors, TVOC 2 will command the tripping of QF2 circuit-breaker only For each light signal detected by a light sensor belonging to the row of X3 detectors, TVOC 2 will command the tripping of QF3 circuit-breaker only As regards the connections to be carried out between circuit-breaker and TVOC-2, reference must be made to the example on page 15. 1 2 3 4 5 6 7 8 O N X3X2X1 43 44 Trip QF1 53 54 Trip QF2 63 64 Trip QF3 X3X2X1 43 44 Trip QF1 53 54 Trip QF2 63 64 Trip QF3 X3X2X1 43 44 Trip QF1 53 54 Trip QF2 63 64 Trip QF3

12  Arc Guard System™ | ABB 3. Assemblies equipped with devices limiting internal arc effects  (concept of active protection) The figure below shows another application example in which – in this case – the simultaneous opening of three circuit-breakers is required. As it can be seen from the figure, it is evident that in the event of an electric arc it is not sufficient to make only one circuit- breaker open since the arc itself might be supplied by the other sources in parallel. In this case the opening of the three circuit-breakers represent a fundamental aspect (also in this case to simplify the example only 5 light sensors of the 30 available have been represented). to the other supply source QF1 QF2 QF3 to the other supply source to the passive loads G

ABB |  Arc Guard System™ 13 From an operational point of view: To set this function on the TVOC-2 it is necessary to set cor-rectly the dip switches positioned on the left side of the unit itself as shown in the following figure: In this way, TVOC-2 will make the circuit-breakers QF1-QF2-QF3 trip simultaneously: For each light signal detected by a light sensor belonging to any row (X1-X2-X3), TVOC-2 will command the trip of all the circuit-breakers QF1-QF2-QF3. Refer to the example on page 15 for the wiring between the circuit-braker and the TVOC-2. 1 2 3 4 5 6 7 8 O N X3X2X1 43 44 Trip QF1 53 54 Trip QF2 63 64 Trip QF3

14  Arc Guard System™ | ABB 4. Application example The following pages show an application example aimed at explaining and giving further information about the connec-tions to be carried out between Emax circuit-breaker with PR122 LSI, equipped with the module PR120/K and TVOC 2.  In case of internal arcing, the bright sensors will command opening for all the circuit-breakers in the assembly. The following Figure shows, as a mere indication, the position-ing of the circuit-breakers inside the switchgear. As regards positioning of the bright sensors inside the as-sembly, it is necessary to follow the description reported at page 5. QF1 QF2 QF3

ABB |  Arc Guard System™ 15 The following electrical diagram shows the connections to be made between TVOC-2 and the trip units of the circuit- breakers (galvanically insulated 24Vdc power supply is needed for the trip units). PE A1 N A2 L1 100=240V AC100=250V DC 100-240Vac 100-250Vdc 73 74 63 64 K6 Trip 53 54 K5 Trip 43 44 K4 Trip 34 32 K3 Trip 31 24 22 K2 Trip 21 14 12 K1 IPoF 11 K9 K9 9 K9 XK6 XK6 10 K7 K7 K7 K51 K51 IN1 SIGNALLING MODULE PR120/K K51 p1 K51 p2 K51 p3 K51 p4 PR122/PPR123/P K10K10 7 K10 XK6 XK6 8 K5 K5K5 K8K8 5 K8 XK6 XK6 6 K6K6 1 K5 XK6 XK6 2 K4K4 3 K4 XK6 XK6 4 K3K3 K3 K9 K9 9 K9 XK6 XK6 10 K7 K7 K7 K51 K51 IN1 SIGNALLING MODULE PR120/K K51 p1 K51 p2 K51 p3 K51 p4 PR122/PPR123/P K10K10 7 K10 XK6 XK6 8 K5 K5K5 K8K8 5 K8 XK6 XK6 6 K6K6 1 K5 XK6 XK6 2 K4K4 3 K4 XK6 XK6 4 K3K3 K3 K9 K9 9 K9 XK6 XK6 10 K7 K7 K7 K51 K51 IN1 SIGNALLING MODULE PR120/K K51 p1 K51 p2 K51 p3 K51 p4 PR122/PPR123/P K10K10 7 K10 XK6 XK6 8 K5 K5K5 K8K8 5 K8 XK6 XK6 6 K6K6 1 K5 XK6 XK6 2 K4K4 3 K4 XK6 XK6 4 K3K3 K3 + – QF1 QF2 QF3 QF1 QF2 QF3 QF1 QF2 QF3

16  Arc Guard System™ | ABB 4. Application example Configuration procedures: TVOC-2Since in case of detection by any light sensor the opening of all the circuit-breakers is required, it is necessary to set ac-cordingly the dip switches at the bottom of the module on its left side. Having set the dip-switches 3 and 4 as shown in the figure, for every light flux detected by any sensor there will be the tripping of all the three circuit-breakers. For each light signal detected by a light sensor belonging to any row (X1-X2-X3), TVOC-2 will command the opening of all the circuit-breakers QF1-QF2-QF3. 1 2 3 4 5 6 7 8 O N X3X2X1 43 44 Trip QF1 53 54 Trip QF2 63 64 Trip QF3

Menu Protections Measures Settings General settings Settings Circuit Breaker Plant Modules Test DIALOG Module Zone selectivity SIGNALLING module Data logger Device test ABB |  Arc Guard System™ 17 Emax PR122+PR120/K (solution valid also in case of PR123+PR120/K)As mentioned in the previous pages, to reduce the total trip times it is possible to use the input digital contact of the sign-aling module PR120/K.To customize properly this module, in addition to the possibil- ity of configuring it directly from the menu of the trip unit, it is possible to use the accessories PR010/T, BT030, PR120/D-BT. The following pages show the navigation path to follow from the display of PR122. From the menu choose “settings” Select “modules” In this section it is possible to navigate and configure the different modules of the trip unit, in this case select “signalling module”

SIGNALLING module Relay n.1 Relay n.1 Relay n.1 SIGNALLING module Relay n.1 Relay n.1 Input Relay settings Input Password 0 Input Function Delay Polarity Password settings Active high 18  Arc Guard System™ | ABB 4. Application example In the section relevant to the module SIG-NALLING, it is possible to configure 4 output contacts which allow the remote signalling of alarms and trips of the circuit-breaker and 1 input contact. Since in our case we have to configure the input contact, scroll to the bot-tom. Select “input” At this point it is necessary to configure correctly the three parameters of this digital contact so that for each 24Vdc input signal, the trip unit will command the circuit-breaker opening. Select “polarity” Enter password

Polarity Active high Active low Password 0.00 s Function External trip Trip reset Generic Set B Input Polarity Delay Function Active high Input Polarity Function Delay Active high ABB |  Arc Guard System™ 19 In the section “polarity” it is necessary to select “active low” since we want that for every 24Vdc signal arriving to this input digital contact (therefore a change of state from 0V to 24Vdc), the set function (in our case the trip of the circuit-breaker) is activated. The polarity “active high” is inverse with respect to the ”active low”, in this case the set function is activated only when the input signal sees a change from 24Vdc to 0V. In this section it is possible to set the opera-tion we want to have when the input contact receives the signal. In this case, since the circuit-breaker trip is required, it is necessary to select the function “external trip”. Through this parameter it is possible to set the activation delay of the system in the range from 0.00s to 100s with 0.01s step. In our case, since we want that the opening operation occurs in the shortest time as pos-sible, it is advisable to give a setting of 0.00s.

20  Arc Guard System™ | ABB

Contact us ABB SACEA division of ABB S.p.A.L.V. BreakersVia Baioni, 3524123 Bergamo - Italy Tel.: +39 035 395 111 Fax: +39 035 395306-433 www.abb.com ABB ABCewe-ControlSE-721 61 VÄSTERÅS, SwedenTelephone +46 21 32 07 00Telefax +46 21 12 60 01 www.abb.com/lowvoltage  The data and illustrations are not binding. We reserve the right to modify the contents of this document on the basis of technical development of the products, without prior notice. Copyright 2011 ABB. All rights reserved. 1SDC007407G0201 - 02/2011