1. HVAC Fan and Damper Sequence Control
Automating the start-up sequence between an outdoor air damper actuator and a main ventilation fan in an air handling unit (AHU) inside a plant or commercial building.
Problem SolvedStarting a supply fan before the dampers are fully open creates severe static pressure spikes, risking ductwork damage. Using the 'On-Delay' timing function, the relay ensures the damper has adequate time to open (via the first pole) before enabling the fan motor starter circuit (via the second pole).
HVAC automationOn-Delay timingDPDT contactsAir handling unitDamper sequence
2. Conveyor Blockage and Overflow Protection
Triggering machine halts or alarm signals on a production line when a material transport conveyor experiences a prolonged jam.
Problem SolvedStandard passage of items triggers sensor fluctuations that shouldn't stop the machine. By integrating a proximity sensor with the relay configured for 'Off-Delay' or 'Interval' timing, brief signal drops are ignored, and a system halt is only initiated if the sensor remains continuously blocked beyond a set threshold.
Conveyor controlOff-DelayMaterial handlingProximity sensor integrationNuisance trip prevention
3. Alternating Pump Duty-Standby Control
Cycling two redundant sump pumps or cooling pumps at set intervals to guarantee even wear-and-tear across long operational runs.
Problem SolvedWhen one pump runs constantly, it experiences premature mechanical wear while the standby pump risks seizing up. Utilizing the 'Repeat Cycle' timing function, the relay's dual DPDT contacts automatically alternate operational command between Pump A and Pump B at defined intervals (e.g., every 12 hours) while maintaining electrical isolation.
Duty-standbyRepeat CyclePump alternationDPDT isolationWear equalization
