A float switch for electric pumps is the cheapest and easiest method of protection against dry running pumping equipment. Such a switch is also called a float.
To date, there are a huge variety of different methods for controlling pumps, but the most popular, due to its simplicity, is a float switch. The main advantage of such a device is that the floats can be simultaneously used as a
water level sensor and an actuator for controlling the pump.
The float switch is installed in tanks, storage tanks, tanks, wells, it is designed to control industrial and domestic water supply, sanitation and sewage pumps. Several such floats can be installed in one tank, each of which will fulfill its function: control of the main pump, auxiliary unit, as an emergency sensor for overflow sensor. The use of such devices in these systems provides
reliable protection of pumping equipment, first of all, from working in the prohibited "dry running" mode. Also, when filling various containers, the switches provide protection against overflow. There are two types of float switch: light (IGD2 / S, IGD5 / S, IGD10 / S) and heavy (MAC / 3, MAC / 5-5S). Basically, light devices are used in drainage and water supply systems, and heavy ones are used for sewage, drainage, rainwater, etc.
Structurally, the float switch is a sealed floating plastic box inside which is placed a steel ball and an electric switch. When the position of the float changes, the ball closes or opens the contacts of the switch. A float switch goes on sale with a wire length of two to ten meters, depending on the type of device. Moisture resistant cable has three cores. Most often they have this color: blue and brown (from normally closed and open contacts), as well as black (general). The cable outlet is sealed with a mechanical seal, it is equipped with a reliable mechanism for relieving mechanical stress in the wire. The insulated cable entry cavity is filled with polymer resins that prevent moisture from entering. Float switch due to heat resistance and chemical properties of the housing, as well as the cable sheath,
consisting of thermoplastic rubber, is highly resistant to fecal waters, uric acid, alcohols, gasoline, liquid oils, fruit acids, etc. The plastic surface of the case has no pores, thereby eliminating the possibility of various contaminants sticking to it, and paper, sand and other solid elements slide off it and thereby do not affect the buoyancy of the device.
How much does a float switch cost? The price of such a device is rather low. The simplest switches will cost about 300-400 rubles. However, the prices of some models can reach several thousand rubles.