·Some details are not shown. Please refer to specification sheets for all information.

LTWTN

Power Transducer Series LT-UNIT

WATT TRANSDUCER
(self-powered)

Functions & Features
• Provides a DC output signal and a pulse totalizer signal in proportion to AC active power
• Convenient pulse unit output (Wh×10n)
• Measuring bidirectional power flow
• DC output containing little ripple is ideal for computer input
• “Time division multiplication” method accepts distorted waveforms
• Isolation up to 2000 V AC
• High-density mounting
• Conforms to IEC 60688
• No auxiliary power supply required
Typical Applications
• Centralized monitoring and control of power management system in a manufacturing facility or building
• SCR – Silicon Controlled Rectifier
 

MODEL: LTWTN–[1][2][3][4][5][6]

ORDERING INFORMATION
• Code number: LTWTN–[1][2][3][4][5][6]
Specify a code from below for each [1] through [6].
(e.g. LTWTN-115A2/T/Q)
• Special output range (For codes Z & 0)
• Specify the specification for option code /Q
 (e.g. /C01)
• Use Ordering Information Sheet (No. ESU-3355).
How to determine Pulse Unit
[Example]
3-phase / 3-wire, VT 3300/110 V, CT 250/5 A, calibration range 750 W
10 [kWh/pulse] ÷ ((3300÷110) × (250÷5))
= 6.666 × 10–3 [kWh/pulse]
= 6.666 [Wh/pulse]
Check that the required pulse unit is within the available frequency range, 0.006 – 3.12 Hz.
Input Range [W] ÷ (Calculated Pulse × 3600[s])
= 750 ÷ (6.666 × 3600)
= 0.03125 [Hz]

[1] CONFIGURATION
1: 3-phase / 3-wire
2: Single-phase / 2-wire
3: Single-phase / 3-wire
4: 3-phase / 4-wire

[2] VT INPUT (unbalanced load)
For 3-phase / 4-wire, phase voltages (e.g. 110 V / √3 ) are used.
1: 110 V AC
(Not selectable for single-phase/3-wire system.)
2: 220 V AC
(Not selectable for single-phase/3-wire system.)
4: 220 V / 380 V AC (3-phase/4-wire only)
A: 100 V / 200 V AC
(single-phase / 3-wire only)

[3] CT INPUT (unbalanced load)
Current
1: 1 A AC
2: 2 A AC
5: 5 A AC

[4] DC OUTPUT
Current
A: 4 – 20 mA DC (Load resistance 500 Ω max.)
D: 0 – 20 mA DC(Load resistance 500 Ω max.)
F: 0 – 10 mA DC (Load resistance 1000 Ω max.)
G: 0 – 1 mA DC (Load resistance 10 kΩ max.)
J: 0 – 5 mA DC (Load resistance 2000 Ω max.)
FW: -10 – +10 mA DC (Load resistance 1000 Ω max.)
GW: -1 – +1 mA DC (Load resistance 10 kΩ max.)
JW: -5 – +5 mA DC (Load resistance 2000 Ω max.)
Z: Specify current (See OUTPUT SPECIFICATIONS)
Voltage
1: 0 – 10 mV DC (Load resistance 10 kΩ min.)
2: 0 – 100 mV DC (Load resistance 100 kΩ min.)
3: 0 – 1 V DC (Load resistance 1000 Ω min.)
4: 0 – 10 V DC (Load resistance 10 kΩ min.)
5: 0 – 5 V DC (Load resistance 5000 Ω min.)
6: 1 – 5 V DC (Load resistance 5000 Ω min.)
1W: -10 – +10 mV DC (Load resistance 10 kΩ min.)
2W: -100 – +100 mV DC (Load resistance 100 kΩ min.)
3W: -1 – +1 V DC (Load resistance 1000 Ω min.)
4W: -10 – +10 V DC (Load resistance 10 kΩ min.)
5W: -5 – +5 V DC (Load resistance 5000 Ω min.)
0: Specify voltage (See OUTPUT SPECIFICATIONS)

[5] PULSE OUTPUT (open collector)
0: None
1: 2.777 Hz at 100 % input
2: Specify pulse unit (within 0.006 – 3.12 Hz)

[6] OPTIONS (multiple selections)
Terminal Cover
blank: Without
/T: With
Other Options
blank: none
/Q: Option other than the above (specify the specification)

SPECIFICATIONS OF OPTION: Q
COATING (For the detail, refer to M-System's web site.)
/C01: Silicone coating
/C02: Polyurethane coating
/C03: Rubber coating

GENERAL SPECIFICATIONS
Connection: M4 screw terminals (torque 1.2 N·m)
Screw terminal: Chrome-plated steel
Housing material: Flame-resistant resin (black)
Isolation: Voltage input to current input to DC output to pulse output
Computation: Time division multiplication
Overrange output: Approx. -10 to +120 % at 1 – 5 V
Zero adjustment(DC output): -5 to + 5 % (front)
Span adjustment(DC output): 95 to + 105 % (front)

INPUT SPECIFICATIONS
Frequency: 50 or 60 Hz
VOLTAGE INPUT
Operational range
: 85 – 110 % of rating
Overload capacity: 150 % of rating for 10 sec., 110 % continuous
CURRENT INPUT
Operational range
: 0 – 120 % of rating
Overload capacity: 4000 % of rating for 1 sec., 2000 % for 4 sec., 120 % continuous
How to determine Wattage Range
Calibration Range [W] = Measuring Wattage ÷ ((VT Ratio) × (CT Ratio))
Check that the required calibration range is within the available range in the table. Specify this range when ordering.
[Example]
3-phase / 3-wire, measuring wattage 750 kW,
VT 3300/110 V, CT 250/5 A
750 × 103 [W] ÷ ((3300÷110) × (250÷5)) = 500 [W]

OUTPUT SPECIFICATIONS
■ DC Current: -10 – +20 mA DC
Span: Min. 1 mA, max. 20 mA
Offset: Max. 1.5 times span
Load resistance: Output drive 10 V max.
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. 50 msec. (approx.)
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.

INSTALLATION
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)
Magnetic field (ext. origin) effect: ± 0.5 % (400 A/m)
Response time: ≤ 2 sec. (0 – 100 % ±1 %)
Ripple: 0.5 %p-p max.
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 ground)
Impulse withstand voltage: 1.2 / 50 μsec., ±5 kV
(input to output or ground)

STANDARDS & APPROVALS
EU conformity:
EMC Directive 
  EMI EN 61000-6-4
  EMS EN 61000-6-2
Low Voltage Directive
  EN 61010-1
  Measurement Category II
  Pollution Degree 2
 Input to output: Reinforced insulation (300 V)
RoHS Directive
  EN 50581

CONNECTION DIAGRAM

EXTERNAL DIMENSIONS & TERMINAL ASSIGNMENTS unit: mm (inch)

M-System Co., Ltd.