When mode B is selected and the unit is in the timed cycle (clock dip switches in the on position), the load will be turned on with the back up source. At the end of the timed cycle, the unit will return to normal operation until the next preset interval occurs. 

If Mode A is selected, the load be off during the timed cycle and the back up source will be on. At the end of the timed cycle, the unit will return to normal operation until the next preset interval occurs. 

Features:
 

• Ideal for commercial defrost applications or for controlling a circulation pump for a pool or spa 
• Adjustable 15 min to 23 hours and 45 min timing cycle 
• Timed or manual termination 
• User-friendly time clock 
• High power output relays 
• 100% monitoring of inputs and outputs