Site drainer

A liquid filtering and transfer device, comprising:

• a substantially rigid, space enclosing housing said housing having a top end, a bottom end, a sidewall, and an inner cavity and wherein said sidewall of said housing has an inner surface and an outer surface;
• an electrically driven fluid transfer pump having an inlet manifold, surrounded by an inlet strainer, located in a vicinity of its lower end, said fluid transfer pump being disposed within said inner cavity of the housing, and having said inlet manifold located in a proximity of said bottom end of the housing, and wherein said inlet strainer has a plurality of strainer openings fluidly connecting said inlet manifold to said inner cavity, and wherein said strainer openings have a substantially similar strainer opening size;
• a plurality of openings traversing said sidewall, each of said openings fluidly connecting said inner surface of said sidewall to said outer surface of said sidewall, and wherein said openings have a maximum size that is smaller than said strainer opening size;
• an electrical power switch operative to switch said electrically driven fluid transfer pump between an operational state and a standby state;
• and
• a restrained floatation device comprising a restrained float restrained to move only in a substantially vertical direction, said restrained floatation device being functionally connected to said electrical power switch such that when a fluid level within said inner cavity of the housing falls below a preset height, said electrical power switch switches said electrically driven fluid transfer pump to said standby mode, thereby preventing said fluid transfer pump from running while dry and being damaged.