MODEL: 18AT

18AT SPECIFICATIONS

ES-1762 Rev.5 Page 1/4

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

Rack-mounted DCS Signal Conditioners 18-RACK

THERMOCOUPLE ALARM

Functions & Features

• Providing relay contact closures at preset input levels

• Direct input from a thermocouple

• Burnout protection

• High-accuracy cold junction compensation

• Single or dual (Hi/Lo) trip

• Front accessed screwdriver setpoint adjustments

• Enclosed relays

Typical Applications

• Annunciator

• Various alarm applications

MODEL: 18AT–[1][2]–R[3]

ORDERING INFORMATION

• Code number: 18AT-[1][2]-R[3]

Specify a code from below for each of [1] through [3].

(e.g. 18AT-25-R/BL)

• Temperature range (e.g. 0 – 800°C)

Use Ordering Information Sheet (No. ESU-1033) to specify

alarm output code 0 specifications.

[1] INPUT THERMOCOUPLE

1: (PR) (Usable Range 0 to 1760°C, 32 to 3200°F)

2: K (CA) (Usable range -270 to +1370°C, -454 to +2498°F)

3: E (CRC) (Usable range -270 to +1000°C, -454 to +1832°F)

4: J (IC) (Usable range -210 to +1200°C, -346 to +2192°F)

5: T (CC) (Usable range -270 to +400°C, -454 to +752°F)

6: B (RH) (Usable range 0 to 1820°C, 32 to 3308°F)

7: R (Usable range -50 to +1760°C, -58 to +3200°F)

8: S (Usable range -50 to +1760°C, -58 to +3200°F)

N: N (Usable range -270 to +1300°C, -454 to +2372°F)

0: Specify

[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

/BN: No 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

Cold junction compensation: CJC sensor attached to the

input terminals (B thermocouple is without CJC as standard)

Hysteresis (deadband): Approx. 1 %

Front LEDs: Red LED turns on when the coil is energized.

INPUT SPECIFICATIONS

Input: Thermocouples

Minimum span: 3 mV

Offset: Max. 1.5 times span

Input resistance: 20 kΩ minimum

Burnout sensing: 0.1 μA

(PR): Min. Span 370°C, 670°F

K (CA): Min. Span 75°C, 140°F

E (CRC): Min. Span 50°C, 90°F

J (IC): Min. Span 60°C, 110°F

T (CC): Min. Span 75°C, 140°F

B (RH): Min. Span 780°C, 1410°F

R: Min. Span 360°C, 650°F