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KM50-C

Smart Power Monitor

KM50-C

Power and current can be measured simultaneously. Measurement of generated power (regenerative power), leading reactive power, lagging reactive power, and consumed power. Low Cost Power Monitor.

about this Product Family

Ratings

Model KM50-C
Applicable circuit Single-phase two-wire, single-phase three-wire, and three-phase three-wire power
Rated power supply voltage 100 to 240 VAC, 50/60 Hz
The power supply voltage and measurement voltage input are shared (terminals 6 and 7).
Allowable supply voltage range 85% to 110% of rated power supply voltage
Allowable frequency range 45 to 65 Hz
Power consumption 7 VA max.
Rated
input
Rated input voltage 100 to 240 VAC (single-phase, 2-wire): Line voltage
100/200 VAC (single-phase, 3-wire): Phase voltage/line voltage
100 to 240 VAC (3-phase, 3-wire): Line voltage
Rated input current 5 A, 50 A, 100 A, 200 A, 400 A, or 600 A (primary current of Special CT) *
Rated frequency 50/60 Hz
Rated input power With 5-A CT: 2 kW
With 50-A CT: 20 kW
With 100-A CT: 40 kW
With 200-A CT: 80 kW
With 400-A CT: 160 kW
With 600-A CT: 240 kW
Allowable input voltage 110% of rated input voltage (continuous)
Allowable input current 120% of rated input current (continuous)
Rated input load Voltage input: 0.5 VA max. (excluding power supply)
Current input: 0.5 VA max. (for each input)
Time 2010 to 2099 (Adjusted for leap year.)
Accuracy: ±1.5 min/month (at 23 °C)
Time backup period 3 days (without power supply, at 23 °C)
Ambient operating temperature -10 to +55 °C (with no condensation or icing)
Storage temperature -25 to +65 °C (with no condensation or icing)
Ambient operating humidity 25% to 85%
Storage humidity 25% to 85%
Altitude 2,000 m max.
Installation environment Overvoltage category and measurement category: 2, Pollution level: 2

* A special output signal is output as the secondary current from the Special CT.

Performance

Smart Power Monitor

Model KM50-C
Accuracy
*1
Voltage ± 1.0% FS ± 1 digit (at ambient temperature of 23 °C, rated input, and rated
frequency).
However, the accuracy is ± 2.0% FS ± 1 digit for the Vtr line voltage for three-
phase, three-wire power and the Vrs line voltage for single-phase, three-wire
power under the same conditions.
Current ± 1.0% FS ± 1 digit (at ambient temperature of 23 °C, rated input, and rated
frequency).
However, the accuracy is ± 2.0% FS ± 1 digit for the phase-S current for
three-phase, three-wire power and the phase-N current for single-phase,
three-wire power under the same conditions.
Active power Reactive
power
± 2.0% FS ± 1 digit (at ambient temperature of 23 °C, rated input, rated
frequency, and a power factor of 1)
Reactive power formula: Reactive power = v × i × sin θ
* "v" is the instantaneous voltage and "i" is the instantaneous current.
θ is the phase difference between the voltage and current.
Frequency ± 0.3 Hz ± 1 digit (at ambient temperature of 23 °C, rated input, and rated
frequency)
Power factor ±5.0% FS ±1 digit (at ambient temperature of 23 °C, rated input, rated frequency,
and Power factor = 0.5 to 1 to 0.5)
Power factor formula: Power factor = Active power/Apparent power
* Apparent power = √ (Active power)2 + (Reactive power)2
Temperature ± 5 °C two hours after the power is turned ON (after setting the offset to match
the ambient environment)
Low-cut current set value 0.1% to 19.9% of rated current input (in 0.1% increments)
Sampling cycle 100 ms for measurement voltage at 50 Hz and 83.3 ms for measurement
voltage at 60 Hz
Temperature influence *1 ± 1.0% FS ± 1 digit (percentage of power within operating temperature range,
at ambient temperature of 23 °C, rated input, rated frequency, and power
factor of 1)
Frequency influence *1 ±1.0% FS ±1 digit (percentage of power within rated frequency ±5 Hz, at ambient
temperature of 23 °C, rated input, and power factor of 1)
Influence of harmonics *1 ± 0.5% FS ± 1 digit (at ambient temperature of 23 °C, error for superimposed
2nd, 3rd, 5th, 7th, 9th, 11th, and 13th harmonics for a content percentage of
30% for current and 5% for voltage of the basic wave)
Insulation resistance 1) Between all power circuits and all of the RS-485 terminals, OUT1, OUT2,
event inputs, I/O commons, and transistor outputs: 20 MΩ max. (at 500 VDC)
2) Between all current and voltage inputs and all of the RS-485 terminals, OUT1,
OUT2, event inputs, I/O commons, and transistor outputs: 20 MΩ max. (at 500
VDC)
3) Between all current and voltage inputs and the front case: 20 MΩ max. (at
500 VDC)
4) Between all power circuits and the front case: 20 MΩ max. (at 500 VDC)
Dielectric strength 1) Between all power circuits and all of the RS-485 terminals, OUT1, OUT2,
event inputs, I/O commons, and transistor outputs: 2,800 VAC for 1 min
2) Between all current and voltage inputs and all of the RS-485 terminals,
OUT1, OUT2, event inputs, I/O commons, and transistor outputs: 3,600 VAC for
1 min
3) Between all current and voltage inputs and the front case: 3,600 VAC for 1 min
4) Between all power circuits and the front case: 2,800 VAC for 1 min
Vibration resistance Single amplitude: 0.35 mm, Acceleration: 50 m/s2, Frequency: 10 to 15 Hz, 10
sweeps for 8 min each along three axes
Shock resistance 150 m/s2, 3 times each in 6 directions (up/down, left/right, forward/backward)
Weight Approx. 150 g (Power Monitor only)
Degree of protection Front panel: IP66 (when mounted to a panel), Rear case: IP20, Terminal
section: IP00
Memory backup EEPROM (non-volatile memory), No. of writes: 1,000,000 times
Compliant standards EN61010-1 (IEC61010-1), EN61326-1 (IEC61326-1), UL61010-1, CAN/CSA-
C22.2 No.61010-1
Event
inputs
Number of inputs Two event inputs
The common terminal is shared with the OUT1
Voltage input High level: 4.75 to 30 VDC
Low level: 0 to 2 VDC
Input impedance: Approx. 2 kΩ
No-voltage input ON resistance: 1 kΩ max.
OFF resistance: 100 kΩ min.
ON residual voltage: 8 V max.
ON current (at 0 Ω ): 10 mA max.
Minimum input time 5 ms
Transistor
outputs
Number of outputs 5 open-collector outputs (two total power consumption pulse output or alarm
output, and three, 3-state outputs)
The total power consumption pulse output and alarm output use the same
common terminal.
The three, 3-state outputs use the same common terminal.
Output capacity 30 VDC, 30 mA max.
ON residual voltage: 12 V max.
OFF leakage current: 100 μ A max.
Alarm output delay *2 OFF delay: 0.0 to 99.9 s, ON delay: 0.0 to 99.9 s
Characteristic
operating time *3
±200 ms
Commu-
nications
Communications
method
RS-485 (2-wire half-duplex)
Sync method Start-stop
Unit number setting CompoWay/F: 0 to 99, Modbus: 1 to 99
Baud rate 1.2, 2.4, 4.8, 9.6, 19.2, 38.4 kbps
Transmission code CompoWay/F: ASCII, Modbus: Binary
Data length 7, 8 bits
Stop bit length 1, 2 bits
Vertical parity Even, odd, or none
Maximum transmission
distance
500 m
Maximum number of
connected Power
Monitors
CompoWay/F: 31, Modbus: 99
EMC
(Industrial electromagnetic
environment)
EMI
EN61326-1
Radiated RF Electromagnetic Field: CISPR 11 class A
Conducted Emission: CISPR 11 class A
EMS
EN61326-1
Electrostatic Discharge Immunity: EN61000-4-2
Electromagnetic Field Immunity: EN61000-4-3
Fast Transient/Burst Noise Immunity: EN61000-4-4
Surge Immunity: EN61000-4-5
Conducted Disturbance Immunity: EN61000-4-6
Power Frequency Magnetic Field Immunity: EN61000-4-8
Voltage Dip and Interruption Immunity: EN61000-4-11

*1 The error of the Special CT is not included.
*2 There may be error in the alarm output OFF delay and ON delay due to the measurement sampling cycle.
*3 This is the error in the operating time of the alarm output (including the error in the alarm output ON/OFF delays and
      output terminal switch operating time).

CTs

Model KM20-
CTF-
5A
KM20-
CTF-
50A
KM20-
CTF-
100A
KM20-
CTF-
200A
KM20-
CTF-
400A
KM20-
CTF-
600A
Rated primary current 5 A 50 A 100 A 200 A 400 A 600 A
Secondary winding 3,000 turns 6,000 turns 9,000 turns
Application frequency 10 Hz to 5 kHz
Insulation resistance Between output terminal and external case: 50 MΩ min. (at 500 VDC)
Dielectric strength Between output terminal and external case: 2,000 VAC for 1 min
Protective element 7.5 V clamp element
Allowable number of
connections/disconnections
100 times
Inner diameter 7.9 dia. max. 9.5 dia. max. 14.5 dia. max. 24.0 dia. max. 35.5 dia. max.
Operating temperature and
humidity range
-20 to +60 °C 85% (with no condensation)
Storage temperature and
humidity range
-30 to +65 °C 85% (with no condensation)

* If you use a flat cable, select the cable based on the dimensions of the CT.

CT Cable

Model KM20-CTF-CB3
Cable length 3 m

Note: Either use the CT Cable specified by OMRON or use 1.25-B3A crimp terminals and AWG22 wire from J.S.T. Mfg.
          Co., Ltd.