The ARA-120-ABA alternating relay is used in multiple‑load installations to assure equal run time on all loads. They also allow for the addition of more capacity in the event of excess load requirements. The alternating relay provides equal run time on two or more loads by alternating the sequence in which the loads are allowed to start up. In each case, the alternating action is initiated each time the control switch across designated terminals opens. The control switch may be a float, a thermostat, a pressure switch, or a timer contact.