MODEL: LWT

http://www.m-system.co.jp/

LWT SPECIFICATIONS

ES-1975 Rev.16 Page 3/5

I INPUT RANGE

• 3-phase / 4-wire

INPUT

BURDEN (VA)

STD.RANGE

AVAILABLE

RANGE

VOLT. CURR.

±200 W

±1000 W

0.1

/phase

±100 – ±240 W

±500 – ±1200 W

0.5

/phase

0.1

/phase

±350 W

±1750 W

0.1

/phase

±175 – ±420 W

±875 – ±2100 W

0.5

/phase

0.2

/phase

±400 W

±2000 W

0.1

/phase

±200 – ±480 W

±1000 – ±2400 W

0.5

/phase

0.3

/phase

±700 W

±3500 W

0.1

/phase

±350 – ±840 W

±1750 – ±4200 W

0.5

/phase

0.4

/phase

/1A

110V

√ 3

__

/5A

110V

√ 3

__

/1A

190V

√ 3

__

/5A

190V

√ 3

__

/1A

220V

√ 3

__

/5A

220V

√ 3

__

/1A

380V

√ 3

__

/5A

380V

√ 3

__

OUTPUT SPECIFICATIONS

■ DC Output

• DC Current: -10 – + 20 mA DC

Span: Min. 1 mA, max. 20 mA

Offset: Max. 1.5 times span

Load resistance: Output drive 12 V maximum; 10 V for [±]

output

• DC Voltage: -10 – +12 V DC

Minimum span: 5 mV

Offset: Max. 1.5 times span

Load resistance: Output drive 1 mA max. at ≥ 0.5 V

■ Pulse output: Open collector; 0 Hz at 0 W

(cutout at approx. 0.5 – 1.0 %)

Rating: 35 V DC @ 100 mA

ON voltage: ≤ 1 V at 100 mA

ON duration: Max. 0.5 sec., min. approx. 50 msec.

Frequency range:

0 – 2.777 Hz (0 – 100 %) standard; 0 – 0.006 Hz through

3.12 Hz is possible.

•2.777 Hz at 100 % Input

[example] 1000 W calibration range

2.777 [Hz] × 3600 [s] / 1 [kW] = 10000 [pulses/kWh]

•Specified Pulse Unit: Refers to how much electrical energy

(kWh) consumption at the primary of the VT and CT

corresponds to the single output pulse per hour from the

transducer.

Output Frequeny [Hz] = Calibration Range [kW] × VT Ratio

× CT Ratio / Pulse Unit [kWh/pulse] × 3600 [s]

500

1000 W

0

12

OUT

20 mA

500

1000 W

0

5

OUT

10 V

4

0

+1000 W

-1000 W

12

OUT

20 mA

0

+1000 W

-1000 W

0

OUT

+10 V

4

-10 V

s OPERATION DIAGRAM (example)

INSTALLATION

Auxiliary power supply

•AC: Operational voltage range: rating -15/+10 %,

50/60 Hz, approx. 2 VA

•DC: Operational voltage range: rating ±10 %,

or 85 – 150 V for 110 V rating, ripple 10 %p-p max.,

approx. 2 W (18 mA at 110 V)

Operating temperature: -10 to +55°C (14 to 131°F)

Operating humidity: 30 to 85 %RH (non-condensing)

Mounting: Surface or DIN rail

Weight: 450 g (0.99 lb)

PERFORMANCE in percentage of span

Accuracy: ±0.5 % (at 23°C ±10°C or 73.4°F ±18°F,

45 – 65 Hz)

Response time: ≤ 2 sec. (0 – 100 % ±1 %)

Ripple: 0.5 %p-p max.(The output ripple may increase when

there is great difference between the frequencies of input

signal and power supply)

Line voltage effect: ±0.1 % over voltage range

Insulation resistance: ≥ 100 MΩ with 500 V DC

Dielectric strength: 2000 V AC @ 1 minute

(voltage input to current input to DC output to pulse output

to auxiliary power to ground)

Impulse withstand voltage: 1.2 / 50 μsec., ±5 kV

(input to output or ground)