Question 1

What is the difference between In-line and Inside Delta Soft Starter Circuits?

Accepted Answer

The Altistart 48 connected in the motor supply lineThe motor connection depends on the supply voltage, which in this example is a star connection.The motor connection depends on the supply voltage, which in this example is a delta connection.The Altistart 48 connected in the motor delta windingATS48***Q or ATS48***YS316 starters connected to motors with delta connections can be inserted in series in the motor windings. They are powered by a current which is less than the line current by a factor of SQRT 3, which enables a starter with a lower rating to be used.

Question 2

How to upload a pre configured CID/IID file to a MiCOM relay?

Accepted Answer

IssueCannot upload a pre configured CID/IID file to a MiCOM relay.Product LineMiCOM RelaysEnvironmentIEC61850 communicationsCauseMiCOM relays expects a MCL file for IEC61850 configuration settings. ResolutionUnfortunately, a CID/IID file cannot be uploaded directly to a MiCOM relay. The CID/IID file needs to be converted into an MCL file before the configuration settings can be uploaded to the relay. This can be done by following the below steps:1. Depending on the version of IEC61850 edition being used select the appropriate configurator from Tools.2. Once the configurator is open, go to File--> Import SCL3. Select the appropriate SCD/CID/IID file that needs to be converted. 4. Open the SCD/CID/IID and then go to File--> Save.

Question 3

What is the download  link for the trial version of Unity Pro XL 8.0 ?

Accepted Answer

Please check the link below to download Unity Pro S/L/XL V8.0 trial version , taking into consideration that the Unity Pro trial software will run for 21 days before it expires.

Question 4

Can we control circuit breaker through wifi?

Accepted Answer

We can only control On and OFF through isc (which is connected to router Which has wifi )please check more information through the link belowhttps://www.se.com/ww/en/product-range/62072-enerlin-x-com-x/

Question 5

What are the values of earth loop impedance for Compact NSX MCCBs and Masterpact NT/NW ACBs?

Accepted Answer

For earth loop impedance, we can provide the method and the customer calculates it according to his need. Our colleagues of Schneider UK have made Zs calculations for Compact NS and NSX, see the attached file with 5 seconds and 0,4 seconds disconnection times, for a voltage of 230V to earth. We've got loop impedance values for MCBs as well.Please find below the method to calculate the Breaker Earth Loop Impedance (Zs).We calculate the Breaker Earth Loop Impedance (Zs) as follows; Zs = Uo / Ia Where Uo is the voltage to earth and Ia is the current to trip the breaker in a given breaker disconnection time. Usually we consider two breaker disconnection times: 5 seconds and 0.4 seconds, depending of the application. Disconnection time of 5 seconds is used for fixed equipment. i.e. a machine in a factory or a fixed appliance (electric oven) in a house. Disconnection time of 0.4 seconds for portable equipment. i.e. power drill or electric lawn mower. This disconnection time is usually used for final circuits (MCBs)A. For a 5 seconds disconnection time: Get to know the voltage to earth (Uo) Determine Ia, see the breaker tripping curve, to find the cuurent needed to trip in 5 seconds (see example on the attached file “Earth Fault Loop Impedance Summary.ppt”, slide 2 and 3) Calculate Zs = Uo / Ia B. For a 0.4 seconds disconnection time: Breakers with electronic trip units – Micrologic (Compact NSb, Compact NSX) Zs = (Voltage Phase to earth) / (In x Io x Ir x Isd x 1.1) On some trip units “Io” doesn’t exist, in this case consider Io = 1. Breakers with thermal-magnetic trip units (Compact NS, Compact NB, EasyPact EZC, Compact NSX) Zs = (Voltage Phase to earth) / (In x Io x Ir x Isd x 1.2) On some trip units “Io” doesn’t exist, in this case consider Io = 1.

Question 6

what is the Installation guide for RCCB for 3P without neutral ?

Accepted Answer

Please refer the attached document connection in 3P RCCB.You can follow the same document for connection in three-Phase without neutral.>> If you are using Acti9 range RCCB, You don't need to add the resistor with iID Acti9 RCCB. You can directly connect the 3 phase on 3 poles of RCCB (without neutral).>> If you are using the Multi9 ID range RCCB, we need to add a resistance with specific resistance values to be compliant with 380-415V. Please refer the attached sheet for connection & resistance values to e used with multi9 range of RCCB.The devices have a toroid which gets energized on out of balance currents and trips .The toroid does not care if there is 2 or 3 or 4 lines connected to it as far as out of balance current is concerned.If there is 3 phases + N then all the phases and N conductors will vector sum to zero - unless there is out of balance current = trip if exceeding the threshold..If there is 3 phases and No N conductor - then exactly the same applies = sum of the 3 currents = zero or you have a trip condition if the out of balance current is greater than the threshold.We can get by without having a N conductor connected to the RCCB as below - because the test button creates a resistive load outside the toroid at rated voltage to test trip the device.

Question 7

What is the max no. of M580 Modbus Requests that can be handled in a single/one scan cycle, and their forms ?

Accepted Answer

The below questions always cause confusion to anyone who would like to implement Modbus requests in M580 : Presumably, if we have 3 PLCs (1, 2 & 3) that perform read and write requests using "Read_Var" & "Write_Var" blocks simultaneously. So, if we suppose that all CPUs can provide a max of 16 requests per scan on the Ethernet channel. Accordingly : Does a request refer to the no. of implemented "Read_Var" & "Write_Var" blocks inside the the code ?. Or, does a request refer to the no. of open communication connections between each single CPU and the other 2 ones ?If the above is correct (a request refers to the communication connection between 2 CPUs), so if for example PLC1 and PLC2 are performing read and write requests between each other, will the total number of requests between them be 1 or 2 in total (a read request for the read way/route and another write request for the write way/route) ?If we consider the communication of read and write between 2 CPUs as 2 requests in total, so what is the max no. of allowable "Read_Var" & "Write_Var" blocks in a single CPU's code ?If other communication modules are present on each CPU's rack (like NOC, NOM .... etc.) which are performing read and write requests as well, so in this case will the max no. of requests for both read and write be the cumulative number of all requests performed by the present Ethernet channels (like the 16 requests presumed above) ?If NOC's DTM requests are also implemented, do they have other independent max number of requests performed, or those requests shall be considered within the max no. of the system (CPU) in total ?Finally, if the max requests no. is exceeded (>16), will there be a workaround to handle those requests per scan (like disabling a portion of them in the current scan cycle, and swapping them with the current ones in the next scan cycle simultaneously) ? ____________________________________________________________________________________________________________________________________________________________________ Based on the above questions, please consider the below : In the implementation of a Modbus TCP communication between client and server PLCs, there are limitations related to the number of requests that can be supported in a single/one cycle, both on the client and server PLC sides. When the PLC is both in client and server modes, the maximum number of connections authorized by PLC must also be taken into account. For the Client PLC : Depending on the CPU reference, there is a limit on the number of requests that can be executed in one cycle in the Client PLC : If it is explicit messaging, each EFs (READ_VAR, WRITE_VAR or DATA_EXCH) used in the program logic is considered as a request. As a result, there will be as many requests as EFs (READ_VAR, WRITE_VAR or DATA_EXCH) in the sections of the Control Expert PLC applicationIf it is implicit messaging, for a NOC module, each line of the ''Request settings'' tab associated with each device (Server) of the ''Device list'' of the Master DTM (DTM of the NOC in this case) is considered as a request. Similarly, for the NOE module of the M340, Premium or Quantum platform, each line of IO Scanning is considered as a request So, max. no. of supported Modbus requests by M580 CPUs per scan cycle are : For the Server PLC : Like the client, there is a limit on the number of requests that can be processed by the PLC in server mode during a cycle. For M580, the limit on the maximum number of requests that can be handled by the PLC is split between the CPU and the communication modules (NOC). For example, a M580 4040 can process a maximum of 32 requests in server mode during its PLC cycle. In these requests, it can only process 24 via the service port and equipment network, and the other 16 requests are received via the X bus. The below local rack assembly example includes a BMEP584040 CPU, along two BMENOC0301/11 Ethernet communication modules. Therefore, the maximum value in this example apply to the BMEP584040 CPU (described above) : When the incoming requests exceed these maximum values, they are queued in a first-in/first out (FIFO) buffer. The size of the FIFO buffer depends on the selected CPU : Modbus TCP and EtherNet/IP Server: The table below shows the maximum number of Modbus TCP, EtherNet/IP, or UMAS requests that can be served by the CPU's Modbus TCP server at each MAST scan : For the Client/Server PLC : When the PLC is both client and server at the same time, in addition to the two limitations presented above, the limitation linked to the maximum number of authorized connections must be taken into account. Below is the following table listing the maximum number of simultaneous Modbus TCP, EtherNet/IP and UMAS connections on the embedded Ethernet port, depending on the M580 CPU reference : Finally, you can refer to this FAQ < FA168406 >, to know more about Modbus, and its associated function codes

Question 8

What are differences in forms 1,2,3,4 for IEC standards ?

Accepted Answer

Attached extract from IEC61439-2 describing the type of forms.

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

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 11

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 12

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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