ES-1866 Rev.8

18WT

Rack-mounted DCS Signal Conditioners 18-RACK

WATT TRANSDUCER

Functions & Features
• Providing two DC output signals in proportion to AC active power
• Measuring bidirectional power flow
• DC output containing little ripple is ideal for computer input
• "Time division multiplication" method accepts distorted waveforms
Typical Applications
• Centralized monitoring and control of power management system in a manufacturing facility or building
• SCR – Silicon Controlled Rectifier

MODEL: 18WT–[1][2]66–R

ORDERING INFORMATION

• Code number: 18WT-[1][2]66-R
Specify a code from below for each of [1] and [2].
  (e.g. 18WT-1166-R)
• Calibration range (e.g. 0 – 1000 W)
• VT ratio, CT ratio (e.g. VT 3300/110 V, CT 250/5 A)

[1] CONFIGURATION

1: 3-phase / 3-wire
2: Single-phase / 2-wire
3: Single-phase / 3-wire

[2] INPUT (unbalanced load)

1: 110 V / 5 A AC
2: 110 V / 1 A AC
3: 220 V / 1 A AC
4: 220 V / 5 A AC
A: 100 V / 200 V / 1 A AC (single-phase / 3- wire)
B: 100 V / 200 V / 5 A AC (single-phase / 3- wire)

OUTPUT 1

Voltage
6: 1 – 5 V DC (Load resistance 5000 Ω min.)

OUTPUT 2

Voltage
6: 1 – 5 V DC (Load resistance 5000 Ω min.)

POWER INPUT

DC Power
R: 24 V DC
(Operational voltage range 24 V ±10 %, ripple 10 %p-p max.)

GENERAL SPECIFICATIONS

Construction: Rack-mounted; terminal access via screw terminals on the front and connector on the rear; terminal cover provided
Connection
  Input: M3.5 screw terminals (torque 0.8 N·m)
  Output 1: Connector
  Output 2: Connector
  Power input: Supplied from connector
Screw terminal: Nickel-plated steel
Isolation: Voltage input to current input to output 1 to output 2 to power
Overrange output: Approx. -10 to +120 % at 1 – 5 V
Zero adjustment: -5 to +5 % (front)
Span adjustment: 95 to 105 % (front)

INPUT SPECIFICATIONS

Frequency: 50 or 60 Hz
Current Input
Operational range
: 0 – 120 % of rating
Overload capacity: 1000 % of rating for 3 sec., 200 % for 10 sec., 120 % continuous
Voltage Input
Operational range
: 0 – 120 % of rating
Overload capacity: 150 % of rating for 10 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))= 0 – 500 [W]

OUTPUT SPECIFICATIONS

INSTALLATION

Current consumption: Approx. 80 mA
Operating temperature: -5 to +55°C (23 to 131°F)
Operating humidity: 30 to 90 %RH (non-condensing)
Mounting: Standard Rack 18BXx or 18KBXx
Weight: 200 g (0.44 lb)

PERFORMANCE in percentage of span

Accuracy: ±0.5 %
Temp. coefficient: ±0.05 %/°C (±0.03 %/°F)
Response time: ≤ 1 sec. (0 – 90 %)
Ripple: 0.5 %p-p max. (50/60 Hz)
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 output 1 or output 2 or power)
500 V AC @ 1 minute (output 1 to output 2 to power)
2000 V AC @ 1 minute (input or output or power to ground)

CONNECTION DIAGRAM

EXTERNAL DIMENSIONS unit: mm [inch]

TERMINAL ASSIGNMENTS