Question 1

What is the Restricted earth fault protection and how to implement on Low Voltage ?

Accepted Answer

The restricted earth fault protection (ANSI 64REF) can be applied if the downstream power system neutral is earthed at the transformer (document attached).This is a differential protection function that detects the difference between residual currents measured at the neutral earthing point and at the three-phase output of the transformer.Please find attached document describing how to implement the estricted earth fault protection with Masterpact Micrologic 6.0

Question 2

What is the definition of ANSI 25 - Synchro-check?

Accepted Answer

This function checks the voltages upstream and downstream of a circuit breaker and allows closing when the differences in amplitude, frequency and phase are within authorized limits.Characteristics adjustable and independent set points for differences in voltage, frequency and phaseadjustable lead time to take into account the circuit-breaker closing time5 possible operating modes to take no-voltage conditions into account.

Question 3

What is the definition of ANSI 50BF - Breaker failure?

Accepted Answer

If a breaker fails to be triggered by a tripping order, as detected by the non-extinction of the fault current, this backup protection sends a tripping order to the upstream or adjacent breakers.

Question 4

What is the definition of ANSI 67N/67NC - Directional earth fault?

Accepted Answer

Earth fault protection, with selective tripping according to fault current direction.3 types of operation: type 1: the protection function uses the projection of the I0 vectortype 2: the protection function uses the I0 vector magnitude with half-plane tripping zonetype 3: the protection function uses the I0 vector magnitude with angular sector tripping zone ANSI 67N/67NC type 1 Directional earth fault protection for impedant, isolated or compensated neutral systems, based on the projection of measured residual currentANSI 67N/67NC type 2 Directional overcurrent protection for impedance and solidly earthed systems, based on measured or calculated residual current.It comprises an earth fault function associated with direction detection, and picks up if the earth fault function in the chosen direction (line or busbar) is activated.ANSI 67N/67NC type 3 Directional overcurrent protection for distribution networks in which the neutral earthing system varies according to the operating mode, based on measured residual current.It comprises an earth fault function associated with direction detection (angular sector tripping zone defined by 2 adjustable angles), and picks up if the earth fault function in the chosen direction (line or busbar) is activated.This protection function complies with the CEI 0-16 Italian specification.

Question 5

What is the definition of ANSI 46 - Negative sequence / unbalance?

Accepted Answer

Protection against phase unbalance, detected by the measurement of negative sequence current: sensitive protection to detect 2-phase faults at the ends of long linesprotection of equipment against temperature build-up, caused by an unbalanced power supply, phase inversion or loss of phase, and against phase current unbalance.

Question 6

Material Safety Data Sheets (MSDS) or Safety data Sheets (SDS) for Batteries Used in APC UPS 1 Phase Systems

Accepted Answer

Issue:I require the Material Safety Data Sheet (MSDS) or Safety Data Sheet (SDS) for various APC single phase UPS products.Product Line:All APC Single phase UPSEnvironment: All APC UPSCause: The majority of batteries used in APC by Schneider Electric Uninterruptible Power Supply (UPS) systems and Replacement Battery Cartridges (RBCs) are contained within cartridges and are sealed, non-spillable, maintenance-free lead acid batteries. The batteries are a manufactured article consisting of a plastic, sealed case, terminals and flame arrestor vent caps. Case color varies. The electrolyte is contained within the case and consists of the electrolyte held captive in an adsorbed glass mat (AGM) or gel matrix. There is no “free” electrolyte to leak out of the case. Under normal use and handling, there is no contact with the internal components of the battery or the chemical hazards. Under normal use and handling, these products do not emit regulated or hazardous substances. The design life of a sealed lead acid battery is 3-5 years depending on environmental factors. Using the batteries past the end of it’s design life can result in electrolyte leakage. In a few cases, Replacement Battery Cartridges (RBCs) containing High Power Lithium Ion Cell, Phosphate-Based are also used. These batteries are used stricitly in select models found in the Back-UPS Connect family. Resolution: North America UPS Battery MSDS Back UPS, Smart UPS, Easy UPS, Symmetra LX, Symmetra RMAll VRLA RBC, SYBT2, SYBT5Click Here Smart UPS Line Interactive Lithium Ion UPS Battery MSDS UN38.3 SCL500RM1NC / SCL500RM1UC / SCL500RM1UNCN/AClick HereClick HereSMTL750RM2UC / SMTL1000RM2UC / SMTL1500RM2UC N/AClick HereClick HereSMTL2200RMXXX / SMT2K2RMXXX / SMT3000RMXXX / SMT3KRMXXXAPCRBC174-LIClick HereClick Here Smart UPS Ultra UPS Battery MSDS UN38.3 SRTL2K2RM1UC / SRTL2K2RM1UNC / SRTL3KRM1UNC / SRTL3KRM1UWCAPCRBC173-LIClick HereClick HereSRTL50RMBP1U-LIN/AClick HereClick HereSmart UPS Ultra 5K-10K / SRTL180RM2UBP / Smart UPS Modular UltraSRYLBMClick HereClick Here Easy UPS Online Lithium Ion UPS Battery MSDS UN38.3 SRVSL1KRARK / SRVSL2K2RARK / SRVSL3KRARKRBCV181-LI / RBCV182-LI / RBCV183-LIClick HereClick HereSRVL48RMBP2U N/AClick HereClick HereSRVL48RMBP3UN/AClick HereClick Here Schneider Off-Grid UPS Battery MSDS UN38.3 PPS330N/AClick HereClick HerePPS500N/AClick HereClick HerePPS730N/AClick HereClick Here Microsoft Surface Hub 2S & Surface Hub 3 UPS Battery MSDS UN38.3 CSH2Click HereClick Here EU / International UPS Battery MSDS Back UPS, Smart UPS, Easy UPS, Symmetra LX, Symmetra RMAll VRLA RBC, SYBT2, SYBT5Click Here Smart UPS Line Interactive Lithium Ion UPS Battery MSDS UN38.3 SCL500RMI1UC / SCL500RMI1UNCN/AClick HereClick HereSMTL750RMI2UC / SMTL1000RMI2UC / SMTL1500RMI2UC N/AClick HereClick HereSMTL2200RMIXXX / SMT2K2RMIXXX / SMT3000RMIXXX / SMT3KRMIXXXAPCRBC174-LIClick HereClick Here Smart UPS Online Lithium Ion UPS Battery MSDS UN38.3 SRTL1000RMXLI / SRTL1500RMXLIXBP48RM1U-LIClick HereClick HereSRTL2200RMXLI / SRTL3000RMXLIXBP48RM1U2-LIClick HereClick HereSRTL1000RM4UXLI / SRTL1500RM4UXLI / SRTL2200RM4UXLI / SRTL3000RM4UXLIXBP48RM2U-LIClick HereClick Here Smart UPS Ultra UPS Battery MSDS UN38.3 SRTL2K2RM1UIC / SRTL2K2RM1UINC / SRTL3KRM1UINC / SRTL3KRM1UICAPCRBC173-LIClick HereClick HereSRTL50RMBP1U-LIN/AClick HereClick HereSmart UPS Ultra 5K-10K / SRTL180RM2UBP SRYLBMClick HereClick Here Easy UPS Online Lithium Ion UPS Battery MSDS UN38.3 SRVL1KRIRK / SRVSL1KRIRK / SRVL2K2RIRK / SRVSL2K2RIRK / SRVL3KRIRK / SRVSL3KRIRKRBCV181-LI / RBCV182-LI / RBCV183-LIClick HereClick HereSRVL48RMBP2UN/AClick HereClick HereSRVL48RMBP3UN/AClick HereClick Here Schneider Off-Grid UPS Battery MSDS UN38.3 PPS330N/AClick HereClick HerePPS500N/AClick HereClick HerePPS730N/AClick HereClick Here Microsoft Surface Hub 2S & Surface Hub 3 UPS Battery MSDS UN38.3 CSH2N/AClick HereClick Here APC Back UPS Connect UPS Battery MSDS UN38.3 CP12036LIN/AClick HereClick Here

Question 7

How to Upgrade Firmware on Smart-UPS Models Using the Firmware Upgrade Wizard

Accepted Answer

Introduction: Most Smart-UPS models support user-upgradeable firmware. Firmware upgrades can provide product improvements, feature enhancements, and cybersecurity remediations throughout the product lifecycle. Important: During a firmware upgrade, battery backup is unavailable. Equipment powered by the UPS will not be protected from power failures. Depending on the UPS model, UPS output power may need to be turned off before the firmware can be upgraded. The Firmware Upgrade Wizard will advise you on how to proceed.Certain UPS models do not support firmware upgrade using a USB connection. To upgrade the firmware of these UPS units using the Firmware Upgrade Wizard, a local connection via serial cable must be used. The serial cable supplied with the UPS must be used.Ensure the computer remains powered on and the communication connection between the UPS and the computer is maintained throughout the firmware upgrade process.Schneider Electric recommends upgrading Smart-UPS On-Line SRT, XP, and XU firmware only when instructed by Schneider Electric Technical Support or when advised through an official Schneider Electric communication. To view different UPS firmware upgrade methods, refer to FA164737. Applicable models: Click to expand and view details The following UPS model families support user-upgradeable firmware using the Firmware Upgrade Wizard. Supported UPS model families CSHSCLSMCSMTSMTLSMXSRTSRTLXPXU As support for additional UPS models is added over time, the list below identifies UPS models that are not currently supported by the Firmware Upgrade Wizard. UPS models that do not support user-upgradeable firmware using the Firmware Upgrade Wizard Smart-UPS Ultra 5, 8, and 10kVA modelsSmart-UPS Ultra Modular models with the prefix SRYLUPS models with the prefixes SU, SUA, SUM, SURT, SURTA, and SURTDSMX750, SMX1000, and SMX1500 UPS models with ID 11 running UPS firmware version 02.x or earlierDevices not supported in the current release: SMT750RMJ1U, SMT2200, SMC2200XLI-BR Firmware Upgrade: The Firmware Upgrade Wizard automatically identifies the connected UPS and selects the appropriate firmware file. Note: Downgrading firmware to an earlier version is not recommended. Important: Do not disconnect the UPS communication cable, reboot the computer, or attempt to turn off the UPS during the firmware upgrade.If a previous version of the Firmware Upgrade Wizard is installed, uninstall it before downloading the latest version. Step 1 Download the latest version of the Firmware Upgrade Wizard ZIP file, and the Firmware Upgrade Wizard User Guide. Step 2 Important: Verify the MD5 checksum of the downloaded Firmware Upgrade Wizard ZIP file. The current MD5 checksum is 47c9f0ebc3482359d16c0ebc1798eae9. Open Command Prompt.Change the directory to the folder where the downloaded Smart-UPS_Firmware_Upgrade_Wizard_v4.3.8v12a.zip was saved: This is typically done using the "cd" command.For example, if the Smart-UPS_Firmware_Upgrade_Wizard_v4.3.8v12a.zip file was saved to the Downloads folder, the command may be: "cd C:\Users\Username\Downloads", or "cd Downloads" Run the command "certutil -hashfile Smart-UPS_Firmware_Upgrade_Wizard_v4.3.8v12a.zip MD5"Verify that the displayed MD5 checksum exactly matches the value shown above.For example: Step 3 The Firmware Upgrade Wizard ZIP file contains the application and all required UPS firmware files. The accompanying User Guide provides detailed prerequisites, instructions, and screenshots. Follow the Firmware Upgrade User Guide to update the firmware of your UPS. Depending on the UPS model and upgrade path, the firmware upgrade process may take approximately 25 to 30 minutes. If the firmware upgrade does not complete, contact Schneider Electric Technical Support. Provide the UPS model, serial number, UPS ID, and current firmware revision.

Question 8

How to calculate necessary Air flow for cabinet cooling using Altivar variable speed drives heat dissipation.

Accepted Answer

The most precise method for calculating heating/cooling system for cabinet is to use dedicated software for cabinet thermal calculation. ProClima software is available on schneider web. Besides that, it is also possible to calculation required fan flow manually, though certain inaccuracy will be caused by not-knowing the amount of heat dissipated by cabinet walls.Manual calculation can be done based on following known (input) data: - Total heat produced inside cabinet (W) - Ptotal - Max ambient temperature (of cooling air) (deg.C) - Tomax - Max allowed temp inside cabinet (deg.C) - Timax - Parameters of cooling air (specific thermal capacity c, density ro) Min air flow is calculated as :Qmin=Ptotal /(ro*c*(Timax-Tomax)) Where Qmin is in m3/sPtotal in kWro in kg/m3c in kJ/(kg.K)Tomax, Timax in degrees celsiusTo get value of flow in m3/h, multiply result by 3600.Qmin (m3/h) = 3600 * Qmin (m3/s)In case of air:ro=1.1kg/m3 (at 40 degrees Celsius)c= aprox 1kJ/kgKExample:Devices inside cabinet produce total heat losses 560W (Ptotal=0.56kW)Max operational temperature for devices inside cabinet is 50 degrees celsius (Timax=50 C)Temperature of cooling air (ro=1.1kg/m^3, c=1kJ/KgK) never exceeds 25 degrees celsius (Tomax=25 C)Min amount of air is then: Q [m3/s] =0.56 kW /(1.1 kg/m3 * 1kJ/kgK * (50-25)K) = 0.56kW / 27.5 kJ/m3 = 0.020 m3/s = 20 liters/sQ [m3/h] = 3600 * Q [m3/s] = 3600 * 0.020 = 73 m3/h

Question 9

What is meant by Symmetrical and Asymmetrical breaking currents?

Accepted Answer

issue:Customer wants to know the value of the symmetrical and asymmetrical breaking current of the circuit breaker and what do they mean.Environment:Circuit Breaker Resolution:- Symmetrical breaking current is the RMS value of AC component of short circuit current at the instant of separation of the contacts. It does not take into account the DC offset.- Asymmetrical breaking current is is the RMS value of the combined sum of the DC and AC components of the short circuit current at the instant of separation of the breaker contacts. This DC offset is of decaying nature which is dictated by the time constant of the system. As shown in the above picture the DC offset decays in a few cycles and is left only with the symmetrical component. Hence if a breaker has to close before the DC component decays, then the breaker’s breaking capacity is to be calculated for the asymmetrical current at the time of breaking.

Question 10

How to reset Zelio logic password?

Accepted Answer

The password can be reset by clearing the program inside the Zelio either byTransfering a new program to the ZelioOr Clearing the program that already exist by updating the firmwareKindly find the steps a) Clearing the program.b) Module / Update module firmware.c) Clear the Program Contained in the Smart Relay

Question 11

What is the selection criterion of Circuit Breakers for the Capacitor bank application.

Accepted Answer

The selection should be done after derating the Circuit Breaker taking into consideration voltage variation and capacitors tolerances that could increase nominal current up to 1.5In. The Derating factor of 1.5In Where In = Q/ ( Square root of 3 ) Un Q = Capacitor Power Un = Nominal Voltage Choose the Micrologic with delay time selection, so that the Circuit Breaker does not trip due to initial high inrush current. Also to be taken into account are the parameters like supply frequency, operating voltage & harmonics level of the power system for such application. Refer the attached sheet for further details for selection of Circuit Breaker for Capacitor duty application. Note: Use the phase barrier between the phases in Circuit Breaker to prevent flashover due to heavy inrush current.

Question 12

what are the benefits of short circuit current limiting?

Accepted Answer

Benefits of limiting:Long installation service lifeThermal effectsLower temperature rise at the conductor level, hence increased service life for cables and all components that are not self-protected (e.g. switches, contactors, etc.)Mechanical effectsLower electrodynamic repulsion forces, hence less risk of deformation or breakage of electrical contacts and busbars.Electromagneticeffects Less interference on sensitive equipment located in the vicinity of an electric circuit.Savings through cascading Cascading is a technique derived directly from current limiting: downstream of a current-limiting circuit breaker it is possible to use circuit breakers of breaking capacity lower than the prospective short-circuit current (in line with the cascading tables). The breaking capacity is heightened thanks to current limiting by the upstream device. Substantial savings can be achieved in this way on switchgear and enclosures.Discrimination of protection devices The circuit breakers' current limiting capacity improves discrimination with the protection devices located upstream: this is because the required energy passing through the upstream protection device is greatly reduced and can be not enough to cause it to trip. Discrimination can thus be natural without having to install a time-delayed protection device upstream.

Question 13

In a 3 phase system, why does the meter still show voltage reading on one of the phases even after breaking the phase circuit?

Accepted Answer

Issue:Testing phase loss on a meter doesn't result in a null voltage reading.Environmnet:EasyLogic Series Power MetersPowerLogic Series Power MetersResolution:The voltage seen is what we call "phantom voltage", its a known phenomenon with all high impedance power meters. These phantom voltages are normal artifacts of the design and should not pose any safety concerns to the end user.In some cases it'll probably disappear by power cycling the meter. Most power meters are not designed to monitor phase loss, as it'll always assume the presence of the 3 phases and the neutral, depending on your parameters setup. External devices are used to detect such occurrences, like phase control relays.

Question 14

Why is Neutral and Earth (Ground) Connection forbidden Downstream from Main Panel?

Accepted Answer

The question is often asked what is the maximum voltage permitted between the Neutral and Earth (Ground) conductor and if the Neutral and Earth can be bridged to achieve a zero value.This can be a difficult topic, in fact in many cases it can be dangerous. As you will see from the attached document, there are many reasons why it is not allowed.

Question 15

What is the definition of Automatic source-changeover system (or ATSE: Automatic Transfer Switching Equipment) ?

Accepted Answer

An automatic controller may be added to a remote-operated source-changeover system. It is possible to automatically control source transfer according to programmed (dedicated controllers) or programmable (PLC) operating modes. These solutions ensure optimum energy management

Question 16

Which RL(lead resistance from CT to relay) is to be used in Knee Voltage calculation if Current Transformers (CTs) used in High Impedance Restricted Earth Fault are at different distances from relay?

Accepted Answer

Issue:Having two different values for RL ( Lead resistance from the CT to the relay); RL from the phase CT to the relay and RL from the neutral point CT to the relayEnvironment:Protection Function ANSI 64refHigh impedance differentialSepam 80 Current Transformer requirementResolution:In any application where the high impedance differential is used, all the CTs must have the following:- the same ratio,- the same magnetizing curve (same minimum Vk),- the same maximum Rct (current Transformer secondary winding resistance),- if the relevant CTs are not at the same distance from the relay, take the maximum RL.Attached Cahier Technique no.194 for more information about high impedance calculation

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