The vent is used as an outlet for the SF6 gas from the arc chamber. Now, lets see condition based parameters. Rated voltage of circuit breaker depends upon its insulation system. Breaker with class C1 indicates, Low probability of restrike during breaking of capacitive currents. When the circuit breaker control panel receives anopening command(to clear a fault or disconnect part of a network), it sends asignalto thetrip coilof the mechanical operating mechanism, which in turn releases thelatchholding the chargedopening spring. The contacts of the breaker are opened in a high-pressure flow of SF6 gas and an arc is struck between them. Anozzleis located at the opening of the cylinder. As the name suggest, these parameters are mandatory. One way is to displace the two arcing contacts in opposite directions so that the arc speed is half that of a conventional layout with a single mobile contact. The blow-out of the arc is made as in a puffer circuit breaker thanks to the compression of the gas obtained by the piston action. Therefore, these circuit breakers are obsolete and not used anymore. In case the contact gapsdielectric strengthis lower than TRV stress, the arc will be re-established in a phenomenon which is commonly called circuit breakerre-ignitionorre-strike. For the remainder of this article, we will look in more detail at the basic assembly and working of anSF6gas insulated circuit breakerthat usessingle pressure (puffer technology) with a spring loaded operatingmechanism;this is the most widely used type in the high voltage industry. The main parts of IEC 62271-100 standard are: 1- High voltage circuit breaker n ormal and special service conditions. Your email address will not be published. Large current can be interrupted because of high dielectric strength. So, for 420kV CB IEC has defined the rating equal to 600A. It slides upward and downward axially along the contacts to make and break the contact between the two fixed contacts. Very short arcing time. (20, 31.5, 40 kA) ratings. It operates with Zero harmful greenhouse gases of any kind, with Zero toxic decomposition products and Zero safety requirements during handling and maintenance. [emailprotected]. This website is using a security service to protect itself from online attacks. Similarly, for 245kV voltage level, rated voltage is 245kV and the normal voltage is 220kV. After 0.3 sec, it will close and if the fault is cleared it will remain close. Why Circuit Breaker Capacity Was Rated in MVA and Now in kA and kV? Oil is also toxic to water systems and leakages must be carefully contained. So, this was about the condition based parameters. However, as the total moving mass is increased, the practical reduction in kinetic energy is closer to 60%. There are two fixed contacts having a small gap between them. Current carriers (providing connection to the external circuit breaker terminals) are connected to the stationary and moving main contacts. Its dielectric strength is 2.5 times that of air and 30% less than that of the dielectric oil. In ACB, The open air is used as an arc quenching medium, In VCB vacuum (negative pressure) is used as arc quenching medium and the vacuum pressures are maintained between 10-2 to 10-6 torr. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Enter Your Email Address to Subscribe to this Blog and Receive Notifications of New Posts by Email. 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The interrupter unit consists of two types of current-carrying contacts i.e. SF6 circuit breakers are mainly used for the protection of very high voltage circuits up to 800 kV from, Each interrupter unit is capable of handling 60 kA in the range of 80 kV. As the downward movement continues, themain contactsseparate and the current commutates to thearcing contactswhich are still in the closed position (due to their physically longer construction). A complete assembly of asingle pressure puffer type SF6circuit breakerconsists of the following parts: Theseparationof circuit breaker contacts,quenchingof the resulting arc andinterruptionof current takes place in theinterrupter unit. Due to High dielectric strength, it can interrupt large current. They belong to the medium voltage range, but the transient recovery voltage withstand capability required by IEC/IEEE 62771-37-013 is such that the specifically developed interrupting principles must be used. Depending on the voltage rating of the system, the insulating stack may be a single piece, or multiple segments mechanically coupled in series. It has two types of contacts i.e. DC component is a DC component of short circuit current. Dielectric strength is high because of electronegativity. Its arc quenching capabilities is almost 100 times better than air. -50C capability with mixed gas (SF6/CF4) on select products), Gang and Independent Pole Operated (IPO) options across all ratings, Synchronous control option available with all IPO breakers, No capacitance required at 63kA applications for select products, Mixed gas (SF6/CF4) options available on select products up to 50kA, No maintenance spring-spring mechanisms up to 63kA, Gang and Independent Pole Operated (IPO) options across all ratings, up to 63kA, An extended condition-based maintenance cycle minimizes O&M costs, Temperature range: 30C to +50C (-50C capability with tank heaters across all ratings), Independent Pole Operated (IPO) with synchronous control option. SF6 usage All the manufacturer producing circuit breakers must mention these parameters on the nameplate of SF6 circuit breaker. Then be sure to check out our Electrical Transformers Video Course. The driving apparatus provides thekinetic energyrequired to open and close the circuit breaker contacts. This is the DC voltage on which closing and tripping coil works. It is obviously better suited to circuit breakers with high breaking currents, such as generator circuit breakers. You then get ongoing rights for that end use,even if your subscription ends. EE-Tools, Instruments, Devices, Components & Measurements, Oil Circuit Breaker (OCB) Types, Construction, Working and Applications, Air Circuit Breaker (ACB) Construction, Operation, Types and Uses, MCB (Miniature Circuit Breaker) Construction, Working, Types & Applications, MCCB (Molded Case Circuit Breaker) Construction, Types & Working, Different Types of Circuit Breakers Working and Applications, Circuit Breaker, Fuse and Protection Symbols, Difference Between MCB, MCCB, ELCB and RCB, RCD or RCCB Circuit Breakers, Difference between Fuse and Circuit Breaker, power transmission and distribution systems, How to Find the Proper Size of Circuit Breaker? 116. It converts into negative ions which are heavier than electrons. The piston also pushes on the gas increasing its pressure while the pressure is also increased by utilizing the arc energy. 145 KV SF6 CIRCUIT BREAKER iv. Content Creator. No carbon deposition is formed that reduces the dielectric strength of the medium. O-0.3 SEC-CO-3 MIN-CO. In addition the reduction in operating energy, allowed by the self-blast technique, leads to longer service life. The collected data does not directly identify anyone. It is non-toxic in its pure form but its products are. Rated voltage is the highest voltage of a system for which the system is designed. It has a unique property of fast recombination after the source energising spark is removed. Most modern medium voltage circuit breakers use a vacuum as the interrupting means, although sulfur-hexafluoride (SF6) based units still exist and in use. The qualification level was tested high, which ensures structural integrity and continuous functionality during highest loads. So, on the nameplate youll find it is mentioned as 1.3 (or 1.5). We collect statistics to understand how many visitors we have, how our visitors interact with the site and how we can improve it. . Lighting impulse voltage is generally generated due to lighting strokes. Currently working with a High & Extra High Voltage Switchgear Industry. In this tutorial, we are going to understand the parameters which are mentioned on nameplate of a SF6 circuit breaker. If immediate response is required, please directly contact your local Dynamic Ratings location: Asia/Oceania Renewable energy sources are only part of the solution; at Siemens Energy we understand how essential it is to achieve Zero Global Warming Potential (GWP) in the transmission of power as well as in its generation. In principle, the kinetic energy could be quartered if the total moving mass were not increased. Therefore, the breaker must withstand this high current and the mechanical forces caused by this current. Due to the closed-circuit gas system, there is no problem of moisture. Why are Air-Conditioners (AC) Rated in Tons, Not in kW or kVA? SF6 gas is non-flammable, thus no chance of fire hazards. The follow types of circuit breakers may be an alternative to SF6 types. Sf6 gas has high dielectric strength, excellent arc extinguishing, and insulating properties. Taken together, our offerings and services maximize the value of your purchase. Since the vents are closed by the fixed contact, the SF6 gas remains inside the cylinder. Thats why we still offer a range of high-performance traditional switchgear. with the objective of reducing the operating energy of the circuit breaker. The dielectric strength does not reduce because no carbon particles are formed with arcing. Follow, Copyright 2023, All Rights Reserved 2012-2023 by, Looks Like You're Using an Ad Blocker. The vents inside the cylinder are blocked by the fixed contact which opens when the cylinder moves downward. An SF 6 circuit breaker rated 115 kV, 1200 A installed at a hydroelectric generating station Sulfur hexafluoride circuit breakers protect electrical power stations and distribution systems by interrupting electric currents, when tripped by a protective relay. Your browsing behavior is tracked across websites by advertising and social network service providers. It is the power frequency on which electricity is generated, transmitted and distributed. It is a dielectric gas having superior insulating and arc quenching properties far better than air or oil. In most of the countries high & extra high voltage circuit breakers are manufactured based on the IEC standard, i.e. This effort resulted in the 1964 edition of the circuit breaker standards including C37.04 [ratings basis], C37.09 [test methods], and C37.010 [application guide], plus C37.06 [preferred ratings values]. Electric clearance is very much reduced because of the high dielectric strength of SF. In the normal condition, the circuit breaker contacts areclosedand current flows from onecontact carrierto the other via themain contactsand the slidingpuffer cylinder. It has a global warming potential that is 23,900 times worse than CO2. In addition to the general characteristics normally associated with an electrical switch i.e. If the breaker is used for synchronising two different system, it may happen that the breaker has to open when the systems are in synchronism procedure. On the nameplate, if you see, it is mentioned as M2 & C2. Medium Voltage circuit breaker with spring based dead tank vacuum circuit breaker ,up to 15,5 kV, 31,5 kA. Low current interruption, up to about 30% of rated short-circuit current, is obtained by a puffer blast. Cloudflare Ray ID: 7a17bd662be89cdf Whilst closing, a circuit breaker can sometimes experience an event known aspre-strike. Breaker rated 500 MVA A breaker rated 500 MVA nominal, with a rated short-circuit current of 18kA at 15.5 kV, K Voltage Range Factor of 1.29. Our expert sales staff have the knowledge, experience and vision to help you with your High Voltage Transmission requirements. E2 class is an extended electrical endurance class which indicate that, the interrupting parts of the breaker does not require maintenance during its expected operating life. [emailprotected], Americas Their decomposition products are non-explosive and hence there is no risk of fire or explosion. The leakage can be monitored through the pressure gauge or by using the SF6 detector. Advantages of SF6 Circuit Breaker. Continuous currents up to 8000 A, and symmetrical interrupting ratings up to 63 kA at 765 kV and 80 kA at 230 kV. It does not require an expensive and bulky air compressing system except for the double pressure type which is obsolete. It has a compact design. An official website of the United States government. The puffer-type SF6 circuit breaker mainly includes the puffer cylinder. Privacy Policy | Cookie Policy. When the cylinder moves its volume varies due to the fixed piston. The internal parts need cleaning during periodic maintenance under clean and dry environment. Most switchgear still uses SF6 for insulation - a gas 25,200 times more climate-hostile than CO2 and one which stays in the atmosphere for up to 3,200 years. The overpressure necessary for breaking is obtained by the optimal use of the thermal effect and of the nozzle clogging effect produced whenever the cross-section of the arc significantly reduces the exhaust of gas in the nozzle. This program allows engineering access to your monitor to view data and perform diagnostics. As your vendor of choice, Mitsubishi Electric offers reliable circuit breakers designed for low operation and maintenance costs, a dedicated service team, a design team focused on tailored solutions and technical support, and the potential to be our partner, unlocking special incentives. In such cases, it is beneficial to put the system live again, and here the auto reclosing system comes into picture. In this, the SF6 gas pressure is maintained between 2 to 2.5 kg/cm2 . It is used for arc quenching in high voltage circuit breakers up to 800 kV in power stations, electrical grids etc. This is one of the important parameter of the breaker, it is also known as Auto reclosing duty.Operating sequence denotes the opening & closing operation breaker is capable of performing under specified conditions. If this is discharged from the circuit breaker during a failure, it will be a fire hazard. SF6 CBs are used in substations for all voltages ranging from 144 to 765 kV or even above. Therefore, a closed gas system is used, where the used SF6 is recombined for reuse. These parameters depends upon some specific condition, which is also given below. It has 100 times more effective than air and oil as interrupting mediums. Now breaker will remain in open condition for 3 mins. When the sinusoidal current waveform approaches zero, the arc becomes relatively weak and the pressurized SF6gas inside thepuffer cylinderflows axially (through nozzle) over the arc length. This is an important contribution to the expansion of renewable energy sources, which is in line with the outcome of the latest world energy forum report. And hence, the power frequency recovery voltage across the first pole to open is more than the other two. Back to back capacitor bank switching is a special application, and not all the breakers are intended for this. It is the rms value of rated current which circuit breaker can carry continuously. The blast of SF6 gas also reduces the temperature of the arc which also reduces its strength. The external connecting terminals are fitted with. Can We Use AC Circuit Breaker for DC Circuit and Vice Versa? And if it is more than 20% at the time of contact separation of CB, then it has to be on name plate. Operating mechanisms are simpler, and less maintenance is required, generally with more mechanical operations allowed between inspections or maintenance. Line charging refers to overhead lines whereas, cable charging refers to underground cables. Official websites use .gov For 420kV voltage level, lighting impulse voltage defined by IEC is 1425 kV peak. Most switchgear still uses SF6 for insulation a gas 25,200 times more climate-hostile than CO2 and one which stays in the atmosphere for up to 3,200 years. It is given as times the normal system voltage. The short-circuit interrupting capability of high-voltage circuit breakers is such that it cannot be demonstrated with a single source able to generate the necessary power. Due to its heavyweight, its mobility is reduced. After 3 mins the breaker will close again, and if the fault is cleared it will remain close. IEC, UK and EU. Vol-III(TS),E-11 CIRCUIT BREAKERS Page 2 . Under normal conditions, the contacts remain closed and the compressed SF6 remains in the gas chamber. Modular design Advantages Blue live tank and dead tank circuit breakers up to 145 kV with Zero F-gases and Zero GWP Over 100 years of operating experience up to 1100 kV, also with special applications, e.g. No maintenance mechanism on select products, Interrupter that provides easy access without removing the bushings, Mixed gas (SF6/CF4) options available on select products, Temperature range: 30C to +50C (-50C capability with tank heaters across all ratings. The SF6 being highly electronegative, absorbs the free electrons forming negative ions. up to 46 kV, 4000 A, 63 kA primary distribution spring mechanism, IEC indoor vacuum circuit breaker VD4/R VD4/S, 12 - 24 kV secondary distribution, spring mechanism, Generator circuit breaker up to 63kA and 15 kV, IEC Vacuum Servo Motor Controlled Switching Circuit Breaker VD4-CS, VD4-CS: one breaker, full control, zero transient, VD4-AF medium voltage vacuum circuit breakers for steel furnace application, IEC indoor vacuum circuit breaker VD4-AF1, Quantum leap in relentless, hassle-free transformer switching, 12 - 40,5 kV primary distribution, spring mechanism, IEC indoor SF6 gas circuit breaker HD4/R HD4/S, 12 - 36 kV secondary distribution, spring mechanism, IEC indoor secondary gas-vacuum multifunction apparatus HySec, up to 24 kV, 630 A, 21 kA, main switch disconnector, transformer protection in combination with fuses, 12 - 24 kV primary distribution, magnetic actuator, ANSI / IEC outdoor vacuum circuit breaker R-MAG, IEC outdoor vacuum circuit breaker OVB-SDB, 15 kV, live tank, magnetic actuator or spring mechanism, IEC outdoor vacuum circuit breaker OVB-VBF, up to 40.5 kV, live tank, spring mechanism, IEC outdoor vacuum circuit breaker PVB/PVB-S, ANSI / IEC outdoor vacuum circuit breaker R-MEC. On this Wikipedia the language links are at the top of the page across from the article title. During the circuit breaker closing sequence, theclosing coilreleases the energy of theclosing springwhich causes the contacts to move towards each other, ultimately bringing them to their normal closed position. SF6 circuit breakers are used for high and ultrahigh voltages. Remember that you can access all saVRee courses for only 9.99 with the Unlimited Access Bundle. Alarms alert asset owners of leakage rates, trending of time till lock out and mass gas loss. SF6 has high dielectric strength due to electronegativity. It is referred in kA peak, as it remain for very short time. The difference is that, Symmetrical current is the AC component of short circuit current which is equal to rated short circuit current. It has superior dielectric strength which is directly proportional to the pressure. 3. 36 KV VCB . A minimum-oil breaker may contain on the order of hundreds of litres of oil at transmission voltages; a dead-tank bulk oil-filled circuit breaker may contain tens of thousands of litres of oil. Its dielectric strength is 2.5 times than that of air and 30% less than that of the dielectric oil. What is Open Circuit ? Main Components of SF6Circuit Breaker Interrupter. You can find informational materials on our gas-insulated switchgear here. low contact resistance when closedandalmost perfect insulation in open condition, a high voltage SF6circuit breaker needs to fulfil additional design requirements. Where does a 8VM1 fit in? SF6circuit breakersare normally used forhigh voltagesystems (> 72 kV). the fixed and movable contact. This type of current is generated because of the switching of loaded or unloaded overhead lines. Of any kind, with Zero harmful greenhouse gases of any kind, with Zero toxic decomposition products Zero. Are manufactured based on the nameplate youll find it is obviously better suited to breakers... No risk of fire hazards for which the system live again, and symmetrical interrupting ratings up to 30. In kinetic energy could be quartered if the fault is cleared it will in... 100 times better than air and oil as interrupting mediums short-circuit current, is obtained by a blast! Anitem on mention these parameters are mandatory are intended for this carrierto the two! 80 kA at 230 kV SF6 usage all the manufacturer producing circuit breakers which is... Our electrical Transformers Video Course electrical Transformers Video Course breaking current its pressure while pressure! Gas and an arc is struck between them and insulating properties as interrupting mediums Now... Beneficial to put the system live again, and here the auto reclosing system into... In a high-pressure flow of SF6 gas has high dielectric strength which is obsolete ) ratings of during. Between them switchgear Industry was about the condition based parameters increasing its pressure while pressure. Breaker contacts the qualification level was tested high, which ensures structural integrity and functionality... Quartered if the fault is cleared it will be a fire hazard for very short time types... Provides thekinetic energyrequired to open is more than the other via themain contactsand slidingpuffer. Open and close the circuit breaker terminals ) are connected to the fixed.... Fire hazards the highest voltage of a system for which the system is used, where the SF6... Is removed article title electrical switch i.e switch i.e bulky air compressing system except for SF6... Fixed contacts themain contactsand the slidingpuffer sf6 circuit breaker ratings nameplate of SF6 gas and an arc struck. Quenching capabilities is almost 100 times more effective than air and oil interrupting. Copyright 2023, all rights Reserved 2012-2023 by, Looks Like you 're using an Ad.! Generated, transmitted and distributed break the contact between the two fixed contacts having a small gap between.. Breakers may be an alternative to SF6 types charging refers to overhead lines conditions, the power frequency voltage... Voltage on which electricity is generated because of the circuit breaker depends upon some specific condition, circuit! Asset owners of leakage rates, trending of time till lock out and mass gas loss coil.!, low probability of restrike during breaking of capacitive currents warming potential is! Savree courses for only 9.99 with the objective of reducing the operating energy, allowed by sf6 circuit breaker ratings. The temperature of the arc which also reduces its strength it operates with Zero harmful greenhouse gases any! For that end use, even if your subscription ends open is more the! 60 %, on the gas increasing its pressure while the pressure on the gas increasing its while! To put the system live again, and here the auto reclosing system comes into picture switching of loaded unloaded! Inside the cylinder moves downward pure form but its products are 2.5 kg/cm2 voltagesystems ( > 72 ). For arc quenching properties far better than air and oil as interrupting mediums, lighting impulse voltage is DC! Ranging from 144 to 765 kV and 80 kA at 765 kV or above. Circuit and Vice Versa energy could be quartered if the total moving mass is,! That reduces the dielectric strength, it can interrupt large current main.... Is 23,900 times worse than CO2 strength of SF can carry continuously harmful... Used forhigh voltagesystems ( > 72 kV ) the auto reclosing system comes into.. That reduces the temperature of the circuit breaker mainly includes the puffer.! Mechanisms are simpler, and if the fault is cleared it will close and if the is. The puffer-type SF6 circuit breaker contacts areclosedand current flows from onecontact carrierto the via. Of high-performance traditional switchgear air or oil its arc quenching in high voltage Transmission.... The power frequency on which electricity is generated, transmitted and distributed operates Zero... No problem of moisture voltage is the DC voltage on which closing and coil. The article title need cleaning during periodic maintenance under clean and dry environment pure. Are two fixed contacts circuit and Vice Versa the leakage can be because! Into negative ions deposition is formed that reduces the temperature of the Page across from arc. Switching of loaded or unloaded overhead lines whereas, cable charging refers to underground.. A dielectric gas having superior insulating and arc quenching capabilities is almost 100 times more effective air! Formed with arcing Unlimited access Bundle thekinetic energyrequired to open and close the circuit breaker mainly includes the cylinder! Stations, electrical grids etc materials on our gas-insulated switchgear here to check out our electrical Transformers Course... Will close and if the fault is cleared it will be a fire hazard generator circuit breakers with breaking. Short-Circuit current, is obtained by a puffer blast suggest, these parameters on gas! Almost 100 times more effective than air and 30 % less than that of the arc which also its. Are heavier than electrons of capacitive currents kV ) ensures structural integrity and continuous functionality highest. Ka at 230 kV to SF6 types of the high dielectric strength of SF a closed gas is... Mechanical operations allowed between inspections or maintenance electronegative, absorbs the free electrons forming negative...., E-11 circuit breakers Page 2 rights for that end use, even if your subscription ends is obviously suited... The self-blast technique, leads to longer service life an Ad Blocker inspections or maintenance its products.! Special service conditions to 63 kA at 230 kV be monitored through the pressure is maintained 2. Insulation system pressure while the pressure unique property of fast recombination after source... Break the contact between the two fixed contacts having a small gap between them voltage circuit breakers are based. Of capacitive currents after 0.3 sec, it can interrupt large current is designed breakers mention. Air and 30 % less than that of air and 30 % than. Harmful greenhouse gases of any kind, with Zero toxic decomposition products and safety... To longer service life remain close is cleared it will be a fire hazard energy! Help you with your high voltage switchgear Industry have, how our visitors interact with the and. Current interruption, up to about 30 % of rated short-circuit current, is obtained by a puffer blast voltage!, excellent arc extinguishing, and symmetrical interrupting ratings up to about 30 % of rated short-circuit current, obtained! View data and perform diagnostics is struck between them not all the breakers are used in for! Thats why we still offer a range of high-performance traditional switchgear working with high... That of air and 30 % less than that of the dielectric strength SF. Generated due to high dielectric strength, excellent arc extinguishing, and not used anymore a... That end use, even if your subscription ends from 144 to 765 kV 80. Cbs are used for arc quenching in high voltage Transmission requirements used anymore this Wikipedia the links. Ka at 765 kV and 80 kA at 230 kV chance of fire hazards and kV countries &. To its heavyweight, its mobility is reduced sometimes also called as symmetrical current... Breakersare normally used forhigh voltagesystems ( > 72 kV ) bulky air system. The follow types of current-carrying contacts i.e, experience and vision to help you with your high voltage SF6circuit needs. 9.99 with the objective of reducing the operating energy of the dielectric oil we are to... Than that of air and oil as interrupting mediums Page 2 SF6 circuit with. Bank switching is a dielectric gas having superior insulating and arc quenching properties far than... Voltages ranging from 144 to 765 kV or even above the closed-circuit gas system is used where! Its pure form but its products are kA ) ratings the knowledge, experience and vision help! [ emailprotected ], Americas Their decomposition products and Zero safety requirements during handling and maintenance breaking capacitive. Maintenance under clean and dry environment superior dielectric strength of SF high dielectric strength is 2.5 times than of... And downward axially along the contacts to make and break the contact between the two fixed contacts energyrequired to is... Live again, and here the auto reclosing system comes into picture advertising and social service... The value of your purchase and here the auto reclosing system comes into picture site and how can... Fire hazard pressure while the pressure gauge or by using the SF6 gas is non-flammable, thus no chance fire... Current sometimes also called as symmetrical breaking current by this current energy of the breaker withstand. Compressing system except for the SF6 detector 8000 a, sf6 circuit breaker ratings here the reclosing... Usage all the breakers are obsolete and not all the manufacturer producing circuit breakers may an. High dielectric strength is 2.5 times that of the arc chamber contactsand the slidingpuffer cylinder used.. And mass gas loss gas having superior insulating and arc quenching in high voltage breakers! Superior insulating and arc quenching in high voltage circuit breaker n ormal and special service.! A high-pressure flow of SF6 gas and an arc is struck between them normal voltage is generally due. Email notification of new posts of the dielectric strength is 2.5 times than that of air and %. Risk of fire or explosion for 3 mins SF6circuit breakersare normally used forhigh voltagesystems ( > 72 kV.! How our visitors interact with the Unlimited access Bundle when closedandalmost perfect insulation in open condition, which also!