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Technical specifications – Spectrex 20/20MI - Mini Triple IR (IR3) Flame Detector User Manual

Page 28

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Spectrex Inc. - SharpEye

TM

Mini IR3 Flame Detector Manual – TM 787100, Rev. D April 2011

20

5.Technical Specifications

5.1 Electrical Specifications

A. Operating Voltage: 18-32 VDC
B. Power Consumption:

Max. 25mA in Stand-by

Max. 50mA in Alarm

C. Electric input protection: The input circuit is protected against voltage-

reversed polarity, voltage transients, surges and spikes according to
MIL-STD-1275A.

D. Electrical outputs

Dry Contact Relays:

Table 13: Contact Ratings

Relay
Name

Type

Normal
position

Maximum Ratings

Alarm

SPST N.O.

2A at 30VDC or 0.5A at 250 VAC

Fault *

SPST N.C.

2A at 30VDC or 0.5A at 250 VAC

The FAULT relay will normally be energized and the contact will be closed during

normal operation of the detector. The contact will be open at Fault condition or low
voltage.

The relay outputs are not available in the intrinsically safe model 20/20MI-XX-X-C.

4-20mA Current Output:

The 4-20mA is isolated sink option.
The maximum permitted load resistor is 600Ohm.

STATE

Output

FAULT

0 + 0.5mA

BIT FAULT

2mA±10%

NORMAL

5mA±10%

WARNING 10mA±5%
ALARM

15mA±5%

Communication Network:

The detector is equipped with an RS-485 communication link that can be
used in installations with computerized controllers. The communications
protocol is Modbus compatible.

This protocol is a standard and widely used.
It enables continuous communication between a single standard

Modbus controller (Master device) and a serial Network of up to 247
detectors.

It enables connection between different types of Spectrex detectors or

other Modbus devices to the same Network.