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DKM-250 User Manual                                                                                             V-2.0

 

 

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DKM-250 

DC ENERGY  

ANALYZER 

 

 

 

 

The DKM-250 is a precision instrument 
designed for measuring, displaying and 
remote monitoring earth leakage and various 
DC parameters in a DC distribution box.  

The unit features a 32-bit ARM core 
microcontroller. 

The unit is supplied from the measuring DC 
voltage input. Operating range is between 19 
and 150VDC. 

The current input of the unit is isolated from 
the rest of the circuit and has different circuit 
options: 

 External current shunt (standard) 

 Internal current shunt 

 Hall Effect sensor input 

 4-20mA analog input 

The unit has 2 digital inputs and 2 relay 
outputs, both of them programmable for 
required functions. 

Thanks to its isolated RS-485 Modbus RTU 
comport, the device is free from ground 
potential difference issues and data are 
safely transferred to automation and 
monitoring systems. Program parameters 
may be uploaded to the unit through the RS-
485 port. 

The unit may output any measured value as 
analog signal through its 4-20mA port. This 
output allows easy connection to PLC 
systems. 

 

 

 

 

 Displays earth leakage in % 

 Various current input options 

 2 programmable relay outputs 

 2 programmable digital inputs 

 Programmable 4-20mA analog output 

 Demand, Min & Max records 

 Fully isolated RS-485 serial port 

 MODBUS-RTU communications 

 Bidirectional current & power measurement 

 Bidirectional kW-h energy counter 

 Bidirectional A-h counter 

 Hours run counter 

 

Front panel programming

 

 Wide operating temperature range 

 Sealed front panel (IP65 with gasket) 

 

Two part connection system 

 
 
 

     

  

 

DESCRIPTION 

FEATURES 

Содержание DKM-250

Страница 1: ...Thanks to its isolated RS 485 Modbus RTU comport the device is free from ground potential difference issues and data are safely transferred to automation and monitoring systems Program parameters may...

Страница 2: ...the unit Fuses must be of fast type with a maximum rating of 6A Disconnect all power before working on equipment When the unit is connected to the network do not touch terminals Any electrical paramet...

Страница 3: ...ING VOLTAGE LOW AND HIGH LIMITS 4 10 SELECTING VOLTAGE MEASUREMENT INPUT 4 11 ADJUSTING LOW AND HIGH POWER LIMITS 4 12 ADJUSTING THE DEMAND PERIOD 4 13 ADJUSTING THE 4 20mA ANALOG OUTPUT 4 14 SELECTIN...

Страница 4: ...ure in any case Be sure that the unit is not subject to water spill Below conditions may damage the device Incorrect connections Incorrect power supply voltage Voltage at measuring terminals beyond sp...

Страница 5: ...DKM 250 User Manual V 2 0 5 1 1 FRONT AND BACK PANELS...

Страница 6: ...and voltage inputs in close proximity of the unit Fuses must be of fast type with a maximum rating of 6A Use cables of appropriate temperature range Use adequate cable section at least 0 75mm2 AWG18 F...

Страница 7: ...DKM 250 User Manual V 2 0 7 1 3 INSTALLATION DIAGRAM...

Страница 8: ...minimum values PROGRAMMING Save adjusted parameter and switch to the next parameter If long pressed then switch to previous parameter Switch to the upper screen PROGRAMMING increase value Switch to th...

Страница 9: ...ds will turn on If Ah and kWh leds are off the upper screen shows the voltage in volts the mid screen shows the current in amperes and the lower screen shows the power in kilowatts When no yellow led...

Страница 10: ...e will have 0 01V precision Display of measured power If the measured power is below 10kW then it is displayed with 0 001kW precision Between 10kW and 100kW it is displayed with 0 01kW precision Betwe...

Страница 11: ...will turn on and the display will show the alarm information every 2 seconds If multiple alarms are present other alarms may be displayed by pressing the SET pushbutton Alarm 1 High Voltage Alarm Ala...

Страница 12: ...DKM 250 User Manual V 2 0 12 Alarm 5 Low Power kW Alarm Alarm 6 Positive earth leakage alarm Alarm 7 Negative earth leakage alarm...

Страница 13: ...able the programming menu hold both MENU buttons pressed for 2 seconds In order to exit programming menu hold both MENU buttons pressed for 2 seconds If no button is pressed during 1 minute then the u...

Страница 14: ...unters Setting this parameter to 1 causes both positive and negative energy counters kWh values to be reset The parameter value is not saved and always reads 0 Parameter value 0 No operation 1 Reset A...

Страница 15: ...eter to 1 causes the run hour counter to be reset The parameter value is not saved and always reads 0 Parameter value 0 No operation 1 Reset alarms Setting this parameter to 1 causes alarms to be rese...

Страница 16: ...ement range is between 0 001 and 0 100volts This parameter adjusts the overcurrent limit Positive and negative currents are monitored for their absolute value and the alarm occurs for any direction of...

Страница 17: ...s the lower limit of the low voltage alarm If this parameter is set to 0 0 DISB DISB then low voltage is not monitored and no alarm occurs Factory set value is 0 0V Adjustment range is between 0 0 and...

Страница 18: ...ositive and negative powers are monitored for their absolute value and the alarm occurs for any direction of the power flow If this parameter is set to 0 0 then high power is not monitored and no alar...

Страница 19: ...demand negative direction 8 Maximum Voltage Demand 9 Maximum current demand positive direction 10 Maximum current demand negative direction 11 Maximum power demand positive direction 12 Maximum power...

Страница 20: ...rresponding to 4mA current output low limit Factory set value is 0 Adjustment range is between 999 9 and 3000 0 This parameter defines the value corresponding to 20mA current output high limit Factory...

Страница 21: ...rements 1 Earth leakage percent 2 Ah counter positive direction 3 Ah counter negative direction 4 kWh counter positive direction 5 kWh counter negative direction 6 Total run hour counter 7 Minimum val...

Страница 22: ...nt range is 0 to 255 seconds 0 Alarm lock disabled 1 Alarm lock enabled When this parameter is set to 1 even if the alarm cause is removed alarms will persist until manually reset When this parameter...

Страница 23: ...ation Every unit in the same Modbus loop must use the same data rate 0 Baud rate 2400 1 Baud rate 4800 2 Baud rate 9600 3 Baud rate 19200 4 Baud rate 38400 Factory set value is 2 Adjustment range is 0...

Страница 24: ...earth voltage to supply voltage The factory set value is 70 Adjustment range is 0 to 100 This parameter adjusts the lower limit of the ratio of the earth voltage to supply voltage The factory set val...

Страница 25: ...he relay is activated The factory set value is 0 Adjustment range is 0 to 255 seconds This parameter selects the RELAY_1 function The factory set value is 12 Adjustment range is 0 to 17 This parameter...

Страница 26: ...ative earth leakage alarm 12 Follows the digital input_1 13 Follows the digital input_2 14 kWh Ah or hour pulse 15 If the value 1234 is written to Modbus address 35 then the function is active 16 If t...

Страница 27: ...s 0 Adjustment range is 0 to 80 seconds This parameter selects the function performed when the digital input_1 signal is active The factory set value is 0 Adjustment range is 0 to 11 This parameter se...

Страница 28: ...r is reset then it starts counting hours run counter is stopped 7 When signal is activated kWh and Ah counters are reset 8 When signal is activated The hours run counter is reset 9 When signal is acti...

Страница 29: ...0 second 200 ms Adjustment range is 0 10 to 9 99 seconds WARNING Excessive pulse duration may cause a missing pulse This parameter defines the minimum duration between 2 pulses The factory set value i...

Страница 30: ...display the calibration coefficient high 4 digits only Adjust UP and DOWN menu buttons until the value displayed in the second screen is correct When the value is correct then press SET button The uni...

Страница 31: ...urrent input sensitivity calibration mode the first display will show 1CUR The second screen will display the measured instantaneous current from the input The third display will display the calibrati...

Страница 32: ...the ampermeter is 4 00mA When the value is correct then press SET button The unit will switch to 20mA calibration of the 4 20mA output In 20mA calibration mode the first display will show 20mA The se...

Страница 33: ...amming is over hold pressed UP and DOWN MENU buttons for 2 seconds The unit will exit program mode and will turn on all lights for lamp testing purpose Check that all lights are on Press any button to...

Страница 34: ...be downloaded at http www modbus org specs php Data Reading The function 03 read multiple registers will be used for data reading The MODBUS master will send a query The answer will be one of the bel...

Страница 35: ...See below for the checksum calculation 4 CRC high byte Data Writing The function 06 write single register or function 10h write multiple registers is used for data writing A maximum of 32 registers c...

Страница 36: ...ion 4 CRC high byte CRC calculation Here is a procedure for generating a CRC 1 Load a 16 bit register with FFFF hex all 1 s Call this the CRC register 2 Exclusive OR the first 8 bit byte of the messag...

Страница 37: ...s If the value recorded as Modbus Write Password parameter moDB WRIT moDB WRIT moDB WRIT moDB WRIT or 3271 is written to the address 7168 then during next 10 minutes Modbus area can be written and bel...

Страница 38: ...ned word 0 1 13 Default screen Explained ch 4 14 16 BIT R W signed word 1 14 Alarm delay Explained ch 4 15 16 BIT R W signed word 1 15 Alarm lock Explained ch 4 15 16 BIT R W signed word 1 16 Modbus n...

Страница 39: ...0 16 BIT R W unsigned word 0 01 34 Counter selection for pulses Explained ch 4 20 16 BIT R W unsigned word 1 35 Relay_1 control through Modbus Explained in chapter 4 18 as relay function 15 If a value...

Страница 40: ...positive 32 BIT R O unsigned long 0 01 8218 Max demand current negative 32 BIT R O signed long 0 01 8220 Max demand power positive 32 BIT R O unsigned long 0 001 8222 Max demand power negative 32 BIT...

Страница 41: ...ed long 0 1 8260 Ah amperes hour counter negative direction 32 BIT R O unsigned long 0 1 8262 Total run hour counter 32 BIT R O unsigned long 0 1 8264 Alarms Alarm durum kayd 16 BIT R O unsigned word...

Страница 42: ...e RS 485 Protocol Modbus RTU Data Rate 2400 38400baud Isolation 1000V AC 1 minute Operating Temp Range 20 C 70 C 4 F 158 F Max Relative Humidity 95 non condensing Protection Degree IP 65 Front panel w...

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