Overview: The AIRSYS ASLLC controller provides for 3 input alarms and 4 output alarms. All alarms are OPTIONAL; however, they are all active. This means for the input alarms the default “non-alarm” state must be supplied otherwise the system will believe there is an alarm condition and respond according to the descriptions below. The attached document covers alarm detail for software revision 13B46 and higher. Contact the HVAC Support Team if you need information on earlier software revisions: ASNSupport@air-sys.com | 855-874-5380


Three Alarm Inputs:

1. Smoke/Fire: When the system sees a Smoke/Fire alarm all fans will shut down and the dampers will close. This is to prevent the AC system from feeding a potential fire and literally “fanning the flames”

2. Gen Run: When the system is being told that there is a generator running (alarm condition) then the outside air dampers will close and only one HVAC system will be allowed to engage in Mechanical Cooling. The dampers close to prevent the free cooling function from pulling diesel fumes into the shelter. A second HVAC system is prevented from engaging in mechanical cooling to ensure the generator is not overstressed by having to endure the turn-on spike of a second HVAC system while already running the site load and one HVAC system 

3. Prime Power Outage: This signal is ONLY relevant when a DC fail-Over box (ASPCB.2) is part of the config. This signal comes from the DC fail-over system and wires directly into the ASLLC.2 controller. When this signal is received, the system will go into a low power, Supply Fan-only mode. If cool enough outside, the system will continue to cool the site with outside air. If the outside temperature is warmer outside than inside, the system will enter into an emergency ventilation mode at > 85 F inside temp as soon as Toutside < Tinside. 


Four Alarm Outputs:

1. Temp Alarm: Factory set to trigger 18°F (Ht) above set point (77 + 18 = 95°F) OR 34°F (Lt) below set point. Set point (StP) can be changed via the PLD user interface 

2. HVAC 1 Alarm: Indicates WPU1 Mechanical Cooling will not come on without an on-site service visit. Power cycling the controller box assembly (OFF then ON via the 240 VAC breaker in the controller) clears the lockout condition. 

3. HVAC 2 Alarm: Indicates WPU2 Mechanical Cooling will not come on without an on-site service visit. Power cycling the controller box assembly (OFF then ON via the 240VAC breaker in the controller) clears the lockout condition. 

4. Second Compressor Run Alarm: Triggers whenever both the Lead & Lag units are engaged in Mechanical cooling