First, select the appropriate switches. Mercury switches encased in a plastic or neoprene float are recommended. In Figure 25, one switch is used to both start and stop the pump. In Figure 26, one switch is used to start and a different switch is used to stop the pump. In both cases, a separate switch is used to activate the alarm system if the liquid level rises too high in the tank.
Some switches handle power to the pump directly, while others require a relay.
Second, make no electrical connections inside the dosing tank. An alarm system is used to alert the homeowner to a pump malfunction by means of an audible or visual signal. Therefore, the alarm system must be powered in such a way that if the pump circuit fails the alarm will still operate. Provide a means to turn off the alarm without losing power to the pump. Required burial depths for branch circuits.