© 2017 Sontay Limited. All rights reserved
SD-D
Duct Smoke Detector
Issue Number 7.1
30/09/2021
Four Elms Road - Edenbridge
Kent - TN8 6AB - UK
3 of 3
Installation
1. The SD-D should only be installed by a competent, suitably trained technician, experienced in installation with hazardous voltages.
(>50Vac & <1000Vac or >75Vdc & 1500Vdc)
2. Ensure that all power is disconnected before carrying out any work on the SD-D.
3. If the sensor is mounted outside, it is recommended that the unit be mounted with the cable entry at the bottom. If the cable is fed from
above then into the cable gland at the bottom, it is recommended that a rain loop be placed in the cable before entry into the sensor.
4. Select a location in the duct where dust & contaminants are at a minimum (i.e. after filters etc.). Fix the housing to the duct with appro
priate screws.
5. Release the snap-fit lid by gently squeezing the locking tab.
6. Feed the cable through the waterproof gland and terminate the cores at the terminal block. Leaving some slack inside the unit, tighten t
he cable gland onto the cable to ensure water tightness. Maximum cable is 2.5mm², care must be taken not to over tighten terminals.
7. Ensure the supply voltage is within the specified tolerances and snap shut the lid after the connections have been made.
Connections
1. Fault Output Common
2. Fault Output Normally Closed*
3. Smoke Detection Output Common
4. Smoke Detection Output Normally Closed*
5. Supply +24Vac/dc, ±20%
6. Supply 0V
* See alarm conditions
Changing Reset Modes
Manual to Auto reset
•Press and hold the external reset button
•After approx. 5 seconds, the internal green LED will go off for 1 second.
•Release the button and the device is now in auto reset mode. The PCB mounted LED will be constantly lit green.
Auto to Manual reset
•Press and hold the external reset button
•After approx. 5 seconds, the internal green LED will go orange and the external LED will go red for 1 second.
•Release the button and the device is now in manual reset mode. The PCB mounted LED will be constantly lit green.
Calibration & Alarm Conditions
While the detector is auto-calibrating, the internal LED will flash red 6 times a second. When calibration is finished, the LED will change to or-
ange for a few seconds, the calibration is being stored in the volatile memory.
The PCB LED will then be continuously lit green, this also indicates that the sensor is powered correctly and not in alarm.
If the detector is in alarm or a fault has occurred, the internal & external LED’s will change to red.
Under normal operating conditions the relay is energised. Therefore, if any fault develops the relay will de-energise shutting off the equipment
connected to the relay, i.e burner or circulating fan, rendering the installation safe.
Relay status
• Un-powered Open
• Powered Closed
• Alarm Open
Self-Test, Failure Mode & Manual Reset
• The output of the SD-622 can be manually overridden, to check integrity of the field wiring. To operate press the PCB mounted button.
In self-test mode both relay outputs will open, the external and the internal LED will be red.
• The external LED will flash red if the detector fails.
Test
button
LED
SUPPLY
IN
24Vac/dc
RELAY
OUT
FAULT
1 2 3 4 5 6
COM NC COM NC +IN GND
RELAY
OUT
SMOKE DET.
TEST
Whilst every effort has been made to ensure the accuracy of this specification, Sontay cannot accept responsibility for damage, injury, loss or expense resulting
from errors or omissions. In the interest of technical improvement, this specification may be altered without notice.
