[u] u in. Case, polycarbonate IP20 Figure 1. Measured voltage and frequency pulse Wire connectors max 4 mm 2. output

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1 MF4 CAREAY MF4 is a frequency and oss of Mains relay (ROCOF type). Additionally MF4 measures a rotational speed of an asynchronous generator when generator is not connected to grid (generator circuit breaker open). The device is microprocessor controlled and functional parameters can be changed with a computer program or with industrial PC using RS485 bus and MODBUSRTU protocol. CAREAY is a trade mark of Power Factor Ay The MF4 indicate mains loss when the derivative of frequency or frequency deviation exceeds the adjustable set value. The device has three output relays: over frequency (and df/dt >), under frequency (and df/dt <) and frequency window relay. Technical specification General data: Power consumption Auxiliary voltage or MF4x 3. W max 24 VDC 7..4 VDC Output signals : indication: pulse output: The amplitude of output pulse equals the auxiliary voltage and it is square shaped. The polarity of measurement voltage is not indicated. Measurement voltage isolation 3.5 kv Programming protocol: MODBUS RTU * Programming device: PC, PC PCprogram CCRMF4 Mechanical properties [u] 24 u in ( t) out( t) Operational temperature C Size h x w x d 75xx t. [t] Case, polycarbonate IP2 Fixing DINbar Figure. Measured voltage and frequency pulse Wire connectors max 4 mm 2 output Input signals : Rated voltage Auxiliary voltage Current ma Measurement input: Output impedance Ω Input impedance min. 44 kω Voltage loss see. Figure 2 Voltage 3mV.. 5V RMS Output voltage as a function of current.2.. z 98 Voltage max. continuous 4 V RMS 96 Voltage max. s V RMS Uaux= 24 VDC Generatorand mains circuit breaker position: Optical isolation kv Input type (IEC 32) Type (sinking) Maximum current ma at rated voltage (24 VDC) 3 ma OFFstate current max 24 µα Output U% Uaux= 4 VDC Output current I[A] Figure 2. pulse output voltage

2 MF4 CAREAY is a trade mark of Power Factor Ay indication: current output: Current 4..2 ma Allowed load...5 Ω No galvanic isolation type: MF4xn isolation kv MF4xi no current output MF4xw Serial communication: MODBUS RTU ED indicators: Yellow Red Green Connection examples RS485 5VDC (no parity, 2 stop) serial communication supervisory on power on /operational Figure 3 represents the connection of MF4 relay in system where startup and shutdown procedures of asynchronous generator is controlled by PC. Startup, connection to grid: See figure 3. When the MF4 is powered for at least 5 ms, and the initsignal is pulsed (min ms, pulse length adjustable) f<, f> relays are set to grid normal position. When the turbine inlet valve is opened the MF4 measures the rotational speed of Supervisory output: Open collectortype conducting state current 5 ma max the generator. When synchronous speed is achieved the output relay closes contact between pins 6 and 8. This contact can be used directly to close the open state voltage..3 V DC generator circuit breaker or can be used as as input for the controlling PC. This then control the generator Relay outputs: circuit breaker. The supervision of the grid fre quency begins when generator circuit breaker (GCB) Maximum operational voltage 25 VAC / 3 VDC and mains circuit breaker (MSB) have been closed Maximum current 5 A continuous (auxiliary contacts are open) for the adjustable time Isolation 2 kv delay of ms min. If, because of the loss of mains situation, the grid frequency exceeds the set value or the rate of the frequency exceeds its set value the contact of relay 2 or relay 3 ( f< tai f>) opens. This switches the voltage of from the under voltage release of GCB opening the main circuit. The contacts of voltage relay can be connected to this same protection circuit. When the grid is restored, the relays 2 and 3 can be set again to grid normal position with the init input signal in order to start the new startup procedure. If shunt release is used instead of the under voltage release, the relays 2 and 3 should be connected in parallel. If there is no need for the rotational speed information the measurement input pins 29 and 3 of MF4 can be connected in phase conductors between MCB and GCB. In that case, mainsloss protection of the whole plant can be done using one MF4 protection relay.

3 MF4 CAREAY is a trade mark of Power Factor Ay Figure 3. Example connection of MF4 protection relay.

4 MF4 Init Init Delay Setup Delay CAREAY is a trade mark of Power Factor Ay Relay trip (f >, df/dt) INPUTS Inhibit Inhibit 2 Supervisory Output OUTPUTS Supervisory ed f >, df/dt Relay Flashing led MONITORING f<, df/dt Relay f >, df/dt Monitoring f<, df/dt Monitoring Time Figure 4. Timing diagram of the MF4 relay activation. Init Init Delay AND Activate Relays Inihibit NOT AND Setup Delay Inihibit 2 NOT Activate Monitoring Figure 5. Block diagram of the relay activation for the supervisory (monitoring).

5 MF4 OVER FREQUENCY TRIPPING DIAGRAM CAREAY is a trade mark of Power Factor Ay OFimit if x >, y = y else, y = x y Counter AND Over Relay TripDelay OFMWindow Figure 6. Block diagram of the over frequency trip. UNDER FREQUENCY TRIPPING DIAGRAM UFimit if x >, y = y else, y = x y Counter AND Under Relay TripDelay OFMWindow Figure 7. Block diagram of the under frequency trip. MAINSOSS DETECTION Derivate of Derivate imit if x >, y = y else, y = x y Counter Over / Under Relay OFM / UFM Window Figure 8. Block diagram of df/dt tripping. Rpm meter output 4..2 ma Models MF4xn ja MF4xi The output current signal relates to measured frequency. The current signal can be read with PC or with 4..2mA panel meter. The output signal relates to the rotational speed of an asynchronous generator when generator is not connected to grid. The scaling of the output is programmable. Obs: The frequency information can also be obtained from the pulse output (connector 26, pulse/z) with a tachometer (counter).

6 MF4 CAREAY is a trade mark of Power Factor Ay Relay settings with MODBUS RTUbus All operational parameters of MF4 can be changed with CCRMF4 program. The program is delivered with the device and can also be downloaded at. If the computer do not include the RS485 port (normal PC), the RS485/RS232converter is required in addition to the connection cable delivered with MF4. A suitable converter is for example SIEMENS PCPPIcable (6ES7 93BFXA). MF4 can be connected to MODBUSRTU as slave, if master uses two stopbits without parity check. The MODBUS registers of MF4 that are needed in order to change principal operaationl parameters are presented in Table. The registers are described in detail in appendix. olding Register Parameter DeviceID InitDelay 2 SetupDelay 3 TripDelay 4 RPMFMin 5 RPMFMax 6 RPMWindow 7 OFimit 8 OFMimit 9 OFMWindow OFMDerivateimit UFimit 2 UFMimit 3 UFMWindow 4 UFMDerivateimit 5 PWMOffset 6 PWMConstant 7 BaudRate 8 Parity 9 Flags Input Register Parameter 2 Derivate Coil Register Parameter RPMRelay OFMRelay 2 UFMRelay 3 OKOutput 4 Powered 5 Activeed 6 WEEPROM 7 Testbit The default factory address for MF4 is and baud rate 96. Attention! The MF4 has to be connected into the low impedance input such as between phase conductors or motor terminals. When the inputs of the devices are as open circuit the MF4 easily measures the frequency of interfering magnetic field that is generally 5 z. Special Models MF4 is a versatile relay. Almost all device parameters may be modified and customized by programming. The special models may be delivered with extra price. CAREAY is trademark of Power Factor Ay.

7 MF4 Appendix CAREAY is trademark of Power Factor Ay ODING REGISTER All the register values and addresses are 6 bit DeviceID: The Modbus address of MF4 device. The address is used to indentify the device connected to field bus. The slave devuce address value may be in the range of 28. The address is reserved for the master. The default factory setting for the device is. InitDelay: The minumum time delay that init signal has to be active in order to activate the relays of MF4. The delay value is represented in holding register as tens of milliseconds. The value may be in the range of The default value is, which represents time delay second. Setup Delay: The time delay that is required after the activation of relays and deactivation of inhibit signals when the MF4 goes to the supervisory state and starts the monitoring of distribution network frequency. The delay value is represented as tens of milliseconds. The value may be in the range of The default value is, which represents time delay second. Trip Delay: The time delay that affects the functionality of both frequency relays. If the over or underfrequency in detected, the MF4 waits trip delay again. If the same crossing of frequency limit is detected again, the relay will be tripped. The value may be in the range of The default value is, which represents time delay second. RPMFMin: The lower frequency of frequency window relay. The default value is 49 z. The frequency is calculated with equation: 6 5 z value =, () 4 f where f is frequency. RPMFMax: The upper frequency of frequency window relay. The default frequency value is 5 z. The value is calculated using equation. RPMWindow The length of window, which defines how many subsequent frequency limit crossings is required to activate the RPM relay. The default value is 4. OFimit: The tripping limit of over frequencymainsloss relay. The value is calculated using equation. The default frequency value is 5.3 z.

8 MF4 Appendix CAREAY is trademark of Power Factor Ay OFMimit: The upper frequency after which the supervising of frequency starts. The value is calculated using equation. The default value is 5. z. OFMWindow: The length of window, which defines how many subsequent crossings of over frequency or derivate limits is required in order to determine that frequency or derivate limit is crossed. Only positive derivate values are calculated. The default value is 4. OFMDerivateimit: The frequency derivate limit for over frequencymains loss relay. The default derivate value is 5 z/s. The value may be calculated using equation: df value = *. (2) dt UFimit: The under frequency limit for the under frequencymains loss relay. The frequency is calculated using equation. The default value is 49.7 z. UFMimit: The upper frequency limit for under the frequencymains loss relay. At the lower frequencies, the relays starts monitoring distribution network frequency. UFMWindow: The length of window, which defines how many subsequent crossings of under frequency or derivate limits is required in order to determine that frequency or derivate limit is crossed. Only negative derivate values are calculated. The default value is 4. UFMDerivateimit: The setting for under frequency mains loss relay. The default absolute value is 5 z/s. The register values are determined using equation 2. PWMOffset: The offsett coefficient for current output. The value is set such that at frequency z, the output current is 4 ma. The default value is 29. PWMConstant: The coefficient that determines the scale of current output. The default value is 4. Using it the current scale 42 ma corresponds the frequency scale z. BaudRate: The baud rate of Modbus protocol. The possible rates are 96, 92, 288 and 336. The default value is 96. Parity: The used parity in serial communications: no parity, odd parity, 2 even parity. Currenly only setting: no parity is used. In this case, the number of stop bits is two.

9 MF4 Appendix CAREAY is trademark of Power Factor Ay Flags: The flags that affect functionality of relay. The value set MF4 into autoinit mode. INPUT REGISTER All the register values and addresses are 6 bit : The highest 6 bits of 32 bit counter value representing the measured frequency. : The lowest 6 bis of 32 bit counter representing the measured frequency. The counter value may be converted to frequency using equation: f 5 = 4 6 z ( ). (3) Derivate: The measured frequency derivate INPUTS All Inputs are single bits Init: The init input. It is used to initialize the under frequencymains loss and over frequency mains loss relays. The intialization has to be performed after every tripping. The duration of initialization pulse has to be at minimum the initialization delay. After that the pulse has to be deactivated. Inhibit & 2: The inhibits prevent the frequencymains loss and over frequency mains loss relays to go into the supervisory state. When both inhibit signals are deactivated, the MF4 will enter into the supervisory state after the setup delay. COIS All coils are single bit outputs RPMRelay: The state of frequency window relay. The relay is active, when the measured frequency is inside the set frequency window limits. OFMRelay: The status of over frequency mains loss relay. The coil is active, when the relay is in supervisory state.

10 MF4 Appendix CAREAY is trademark of Power Factor Ay UFMRelay: The status of under frequency mains loss relay. The coil is active, when the relay is in supervisory state. OKOutput: The status of MF4. The status is high when the both relays are active and in supervisory state. Powered: Power switched on and microprosessor in operational state Activeed: The status of MF4. The status is high when the both relays are active and in supervisory state. WEEPROM: When activated, the contents of holding register are save into the EEPROM memory. Correspondingly, in the powerup the device parameters are read from the EEPROM. TestBit: When activated, the relays and outputs of the MF4 can be controlled through Modbus. The initialisation of the MF4 restored the device into the normal state.