Muting the AFA 500
There are four ways to silence the audible alarm on an AFA 500 fume hood or bio-safety cabinet alarm. 1. Temporary mute When the monitor is in alarm mode, press the enter button. The horn will remain off for the duration of the alarm condition. When the
monitor returns to safe mode, the alarm will be re-enabled for the next time the monitor has an alarm condition.
For more information on the TEL AFA 500 in North America, contact Holland Safety Equipment at 847-680-9930 or firstname.lastname@example.org
If the user wants to use a temporary mute with a ringback feature — wherein the audible alarm will resume after a set time period — this can be accomplished by connecting two wires from the relay output terminals to the + and SW terminals on the sash high input relay. Once this connection is made, an low air alarm also will initiate the sash high alarm. If a user pushes the enter button for a temporary mute, it will re- sound after five minutes. 2. Permanent mute When the monitor is in normal operation mode, press and hold the set button for 10 seconds. The audible alarm will beep three times to indicate the alarm is disabled. When the airflow is in the normal/safe condition, the green LED will flash to indicate the alarm has been disabled. When the airflow is in a fail/unsafe condition, the red light will blink and no horn will sound. To undo the permanent mute, press and hold the set button for 10 seconds. The audible alarm will beep three times to indicate the alarm is enabled. NOTE 1: This setting is not stored in the 500’s flash memory, so permanent mute will reset in the event of a power loss. 3. Night Setback This is a “temporary” mute activated by electric input. The monitor has two dry contact relay inputs on the back. To enable night setback, wire an external element (a building automation system or the hood power, the fan power, the room light, etc.) into relay input one. Then, when the external element changes states (turns on/turns off, etc.) it sends a signal to the relay to switch from open to closed. When the monitor enters night setback mode, the audible alarm is disabled. If there is sufficient airflow, the green light will blink. If there is an air fail condition, the red light will flash. Then, when the external element changes states back to the original condition, the relay switches back and the alarm returns to normal operating mode (the horn is re-activated automatically and the green light returns to solid state).
To make sure everything is set properly, activate the blower switch on and off while looking at
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