Sealey SCMA1 User Manual

Page 3

7.2.

Normal Operation

7.2.1. When no Carbon Monoxide is present, the green LED flashes once every 50 seconds, the LCD displays “0 PPM” and the speaker

symbol is indicated to show your alarm is in normal working condition. See fig.3.

7.3.

How to test the CO Alarm

7.3.1. Press the test button, the unit will trigger an analog output of high co concentration that will be detected by the mcu, thus starting

alarming together with the red LED flashing , simultaneously the unit will display the simulated CO concentration with the “SPEAKER”

symbol flashing, (SPEAKER symbol) see fig.4.

NOTE:

Test this alarm when the “ppm” symbol is displayed in the LCD after the batteries have been installed. Though this alarm can

self-diagnose the amplifying circuit and sensor, it is recommended that you test your CO alarm once a month to ensure it is working

correctly.

7.4.

Alarm Locking

7.4.1. If the TEST button is pressed again whilst the CO alarm is sounding, the alarm will move into LOCKING status and the red LED and the

green LED will flash every 10 seconds at the same time, the “SPEAKER” symbol on the LCD will disappear. The unit will not respond to

any action during the 2 minute LOCKING status. If the CO concentration exceeds 300PPM in 3 minutes, the unit will start alarming, see

fig.5.

7.4.2. When the CO concentration goes down to or below 5PPM the unit will stop alarming.

7.5.

Locking Release

7.5.1. Press the TEST button, the unit will return to Normal Operation status, see fig.3.

7.6.

Alarm Condition

7.6.1. When the unit detects dangerous levels of CO, it will emit an alarm signal along with flashing red LED, see fig.4. This will continue as

long as there is a dangerous level of CO concentration of or equal to 5PPM. The unit will emit an alarm along with the flashing red LED.

The LCD will show the concentration and SPEAKER symbol. This will indicate that an alarm has occured and it should be investigated.

fig.3

fig.4

fig.5

Flashes every 50

seconds

SCMA1 Issue: 1 - 30/05/14

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