The LOW ALARM item sets the low face velocity alarm
setpoint. A low alarm condition is defined as when the face
velocity falls below the low alarm setpoint.
Off, 5 to 1000 ft/min
Off, 0.02 to 5.0 m/s
The HIGH ALARM item sets the high face velocity alarm
setpoint. A high alarm condition is defined as when the face
velocity is greater than the high alarm setpoint.
Off, 40 to 1000 ft/min
Off, 0.2 to 5.0 m/s
ALARM CONSTRAINTS
The alarms operate as follows:
1. There is a five second delay between the time an alarm occurs and the time that the alarms lights, audible alarm and alarm relays
activate.
2. Low alarm. The low alarm activates when the velocity drops below the low alarm setpoint. The low alarm stays on until the face velocity
rises 20 ft/min (0.1 m/s) above the low alarm set point.
3. High alarm. The high alarm activates when the velocity exceeds the high alarm setpoint. The high alarm stays on until the face velocity
drops 20 ft/min (0.1 m/s) below the high alarm set point.
The dSPL item is the period of time over which the face velocity
readings are averaged before being displayed. The longer the
display averaging period, the more stable (less fluctuation) the
display.
The ALr item selects how the alarms terminate after the unit
returns to the safe (normal) velocity range. UNLATCHED
(UnLA) automatically resets the alarms when the unit reaches
the safe range. LATCHED (LA) requires the staff to press the
RESET key after the unit returns to the safe range. The ALARM
RESET affects the audible alarm, visual alarm, and relay
outputs, which means all are latched or unlatched.
To Next Page
Loading...
Need help?
General
