Spectrex 20/20MU - Mini Flame Detector - Manual (Page 27)

Spectrex Inc. - SharpEye TM ML & MU Flame Detector Manual – TM 767100, Rev. A, April 2005
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5.Technical Specifications
5.1 Electrical Specifications
A. Operating Voltage: 18-32 VDC
B. Power Consumption:
Max. 35mA in Stand-by
Max. 80mA 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 8: 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 be normally energized closed during normal operation of the
detector. The contact will be open at Fault condition or low voltage.
• 4-20mA Current Output:
The 4-20mA is isolated sink option.
The maximum permitted load resistor is 600Ohm.
STATE 20/20ML Output (mA) 20/20MU Output (mA) To
FAULT 0 0 +0.5mA
BIT FAULT 2 2 ±10%
NORMAL 4 4 ±10%
IR Detect 8 - ±5%
UV Detect 12 - ±5%
WARNING 16 16 ±5%
ALARM 20 20 ±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.