ES-1764 Rev.6

18AR

Rack-mounted DCS Signal Conditioners 18-RACK

RTD ALARM

Functions & Features
• Providing relay contact closures at preset input levels
• Direct input from an RTD
• Burnout protection
• Single or dual (Hi/Lo) trip
• Front-accessed screwdriver setpoint adjustments
• Enclosed relays
Typical Applications
• Annunciator
• Various alarm applications

MODEL: 18AR–[1][2]–R[3]

ORDERING INFORMATION

• Code number: 18AR-[1][2]-R[3]
Specify a code from below for each of [1] through [3].
  (e.g. 18AR-45-R/BL)
• Temperature range (e.g. 0 – 250°C)
Use Ordering Information Sheet (No. ESU-1033) to specify alarm output code 0 specifications.

[1] INPUT RTD (2- or 3-wire)

1: JPt 100 (JIS'89)
(Usable range: -200 to +500°C, -328 to +932°F; min.span: 30°C, 54°F)
3: Pt 100 (JIS'89)
(Usable range: -200 to +650°C, -328 to +1202°F; min.span: 30°C, 54°F)
4: Pt 100 (JIS'97, IEC)
(Usable range: -200 to +650°C, -328 to +1202°F; min.span: 30°C, 54°F)
5: Pt 50 Ω (JIS'81)
(Usable range: -200 to +500°C, -328 to +932°F; min.span: 60°C, 108°F)
6: Ni 508.4 Ω
(Usable range: -50 to +200°C, -58 to +392°F; min.span: 20°C, 36°F)
0: Specify
Note: Consult us for 2-wire RTD

[2] ALARM OUTPUT

1: Hi (coil energized at alarm)
2: Hi (coil de-energized at alarm)
3: Lo (coil energized at alarm)
4: Lo (coil de-energized at alarm)
5: Hi/Lo; N.O., OFF in power failure
(connector output not available)
6: Hi/Lo; N.C., OFF in power failure
(connector output not available)
0: Specify

POWER INPUT

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

[3] OPTIONS

Burnout
blank: Upscale burnout
/BL: Downscale burnout

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)
  Alarm output: M3.5 screw terminals (torque 0.8 N·m) and connector
  Power input: Supplied from connector
Screw terminal: Nickel-plated steel
Isolation: Input to output to power
Relay: Enclosed
Setpoint adjustments: Multi-turn screwdriver adjustments (front); -5 – +105 % independently
Hysteresis (deadband): Approx. 1 %
Front LEDs: Red LED turns on when the coil is energized.

INPUT SPECIFICATIONS

Maximum leadwire resistance: 20 Ω per wire (3-wire)
Sensing current: 2 mA (Pt)

OUTPUT SPECIFICATIONS

Output: Enclosed SPST and SPDT relays
Rating: 120 V AC @ 1 A (cos ø = 1)
30 V DC @ 1 A (resistive load)
0.2 A maximum for the connector output
Maximum switching voltage: 120 V AC or 30 V DC
Max. switching power: 120 VA or 30 W (24 VA or 6 W for the connector output)
Minimum load: 5 V DC @ 10m A
Mechanical life: 5 × 107 cycles

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: 150 g (0.33 lb)

PERFORMANCE in percentage of span

Trip point repeatability: ±0.1 %
Temp. coefficient: ±0.015 %/°C (±0.008 %/°F)
Response time: ≤ 0.5 sec. (0 – 100 % at 90 % setpoint)
Burnout response: ≤ 10 sec.
Line voltage effect: ±0.1 % over voltage range
Insulation resistance: ≥ 100 MΩ with 500 V DC
Dielectric strength: 1500 V AC @ 1 minute
(input to output or power)
500 V AC @ 1 minute (output to power)
1500 V AC @ 1 minute (input or output or power to ground)

EXTERNAL VIEW

EXTERNAL DIMENSIONS unit: mm [inch]

TERMINAL ASSIGNMENTS

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM