Startup
The AFA500/BSC must be field-calibrated once
the room air supply and exhaust is balanced.
When the unit is powered up, the following
sequence of events occurs:
1. The alarm performs a self-test of its
functions, LEDs and audible alarm
(approximately 2 seconds) and then initiates
a delay timer of 30 seconds to allow the
airflow sensor to stabilize.
2. During the 30-second stabilizing period, all
alarms and relay outputs are deactivated
and the red and green LEDs remain on.
3. At the end of the delay, the unit will do one
of two things:
a. If the monitor has been calibrated,
the unit enters normal operating mode
(solid green light for safe velocity, red light
and audible alarm if low velocity).
b. If the unit has not been calibrated,
the red and green LEDs will flash, the audible
alarm will be muted.
Installation &
Calibration Guide
Airflow Monitor
AFA500/BSC
Calibration - Single Point (default)
1. The calibration process establishes an alarm point at 80% of the
flow rate captured during calibration. That is, the alarm value will
be 20% less than standard airflow.
2. Press and hold the ENTER button for 5 seconds to enter Calibration
Mode. This is indicated by both red and green LEDs flashing with
the audible alarm beeping.
3. To initiate calibration, press and hold the ENTER and SET buttons
at the same time. The unit will sample the airflow for 5 seconds,
during which time the green LED goes off and the red LED flashes.
The audible alarm continues to sound during the air sampling.
4. If calibration is successful, the monitor will give a two-tone beep at
the end of the air sample, and then automatically enter run mode.
5. If the ENTER or SET button is released during the air sampling
period, or if the airflow is fluctuating too much, the alarm will emit
a lower-frequency buzzing for a short period and then re-enter
calibration mode. If this occurs, press the ENTER and SET buttons
again to repeat the airflow sampling.
6. If, during normal operation after a successful calibration, the airflow
drops below the alarm point, the unit will go into alarm condition
(red LED flashing, audible horn beeping). Push the enter button to
temporarily mute the horn.
7. The horn can be permanently disabled by pressing and holding the
SET button for 10 seconds. The horn will sound 3 times to indicate
that it has been disabled. In Safe mode the Green LED will flash if
the horn is disabled or be solid to indicate that the horn is enabled.
To enable the horn press and hold the SET button for 10 seconds,
the horn will sound 3 times to indicate that it has been enabled.
Temperature Electronics Ltd. Unit 2, Wren Nest Road, Glossop SK13 8HB UK
T. +44 (0) 1457 865 635 F. +44 (0) 1457 868 843 E. [email protected]
w. www.tel-uk.com
