Wastewater Elevator Selection: 1. When the equipment is configured with a single pump, there is no backup pump, limiting it to wastewater discharge within a single bathroom. The wastewater volume is small, and pump failure is easy to address. 2. With dual pumps, a backup pump is available, allowing the pumps to alternate or serve as backups. Suitable for use in unit basements with moderate water volume. In case of a single pump failure, the other pump can run sufficiently to handle wastewater discharge, and the faulty pump should be repaired promptly. 3. Besides the built-in type, the equipment can also be made external. An external unit means the vertical pipeline wastewater pump is assembled outside the collection tank. The advantage is that maintenance is more convenient, but the drawback is higher noise levels. 4. The pump control cabinet system can be selected in an indoor type or a stainless steel outdoor type.