【 Weak current College 】 heater principle of construction work status 】

As people's standard of living continues to improve and strengthen the capacity of the power supply, a growing number of families choosing electric water heaters. However, the water heater leakage resulting in personal injury accident reports, and enables consumers to electric water heater safety doubts. The following are some of the problems in the hope of eliminating views your concerns, rest assured that boldly use electric water heaters.
To understand household heater safety performance, first on its structure, working principle and work conditions. At present, the market for home use electric boiler mostly belong to the water heater, 1500W power. Commonly there are two: one is the export of open-type electric water heater, multi-channel water supply closed electric water heaters. The two electric water heater body structure is exactly the same, just the way in and out of the water control, which differ in different so that the two heaters are functionally, confined and working conditions, had a large difference. In safety performance requirements also vary.
Export open heater control mode, belonging to the former standard, i.e. through the inlet valve to control on the water heater of the water and the water. Because of this water heater outlet opens into the atmosphere, water drums only withstand internal water pressure. It can be said that there is no pressure. When filled with water heating, water heated volume to expansive, water dripping from the outlet out of a normal phenomenon.
Closed water heater control mode, belonging to the back-control through the outlet valve on the control of the water heater and water. Because of this water heater of the water must be in an open State, so when filled with water, close the valve, the drums will endure and the running water pressure the same pressure. In fact closed electric water heater in the barrel is a pressure vessel, this must be rated working pressure and pressure capacities have agreed, toensure its normal safe operation. On this national standards (GB4706.12-1995): closed electric water heater minimum rated working pressure is 0.6MPa, withstand voltage requirement for the rated pressure of work. At present, the market closed electric water heaters, pressure rated work mostly as 0.6MPa, and must pass the pressure test 1.2MPa to factory. In this way, water heater voltage of security is ensured.
How closed electric water heater at rated pressure work? this task is installed on the inlet valve. Relief valve is actually a one-way valve and a combination of relief. One-way valve also called check valve, it can only make the water into the not out. So the pressure on drums is greater than the running water pressure, you can prevent hot water into the cold water pipe or water in the tap water accidents, prevent hot water loss. At the same time check valves also makes water heater in the barrel of a closed system. When the water heater to heat the filled with water, the pressure inside the barrel is increased. We will drain valve for pressure relief pressure set is slightly higher than the rated pressure of work generally set at 0.7MPa. Thus, once the drums when the pressure exceeds the set pressure, there will be a part of the Park's overflow safety valve, the pressure drop in the bucket to the set pressure following. Safety overflow water dripping on the drain valve at work.
Home use electric boiler heating temperature control, mounted on the water heater temperature and voltage regulator, temperature limiting device. Temperature is generally set in insert metal tube in the water, the highest temperature is generally set at 70-80 ℃, which guarantees that the water heater with a large heat while not in error occurs severely scalded. In order to ensure that the temperature is malfunctioning heating not to out of control, also installed on the water heater temperature limit, the limit temperature value set in slightly higher than the temperature for maximum control of temperature, heating temperature reaches the set value, temperature limiting device immediately cut off power supply, to avoid the heat out of control, leading to the accident.
Closed water heater when you start to use must also be noted that. Due to the pressure of water heater drums directly, so do not put hot water flow all the way up to avoid high-pressure water jetting out scald.
Consumers for home use electric boiler security concerns still afraid of the largest electric shock, in this connection the national standard for electric water heater I class appliances product, that is in addition to the basic insulation and earthing protection, and this has developed a rigorous testing standards. Standard requirements for basic insulation, water heater insulation resistance must be big 2 M Ω, General manufacturers are the targets set at over 10 M Ω. The second requirement is in the water heater live parts and shell between 1250V voltage for one minute of electric strength test. At trial, cannot have a discharge and flashover phenomenon. At the same time in the voltages, 1500W heater leakage current must be less than 1.1mA, this isolation level is not an electric shock can occur. However, in order to be on the safe side, the standard also provides electric water heaters must be very demanding wet test the electric water heater in the relative humidity of 93 ± 2% of wet rooms placed seven days, and then test the above indicators, indicators must be fully qualified to pass. In the grounding protection, standard electric water heater earthing contact resistance must be less than 0.1 Ω, once the basic insulation is compromised, a good grounding will protect will enable insurance blow to prevent electric shock. The heater must have the power to the ground protection.
In recent years, manufacturers in order to ensure safety in the water heater installed earth leakage protection device or use leakage protection plug, if the leakage current of morethan a set value (typically 10-30mA), protector in 0.1 seconds to automatically cut off power supply.
Through the above discussion, we recognize the electric water heater in the pressure, temperature and shock protection are multiple valid measures of protection. As long as the correct use of electric water heater, security is guaranteed. (Of course, the we are talking about security refers to the domestic regular brands).
2. General knowledge of electrical water heater
1. There are three electric water heater, so that the best? it should be said that the scope of application, cannot be generalized. That is hot-Water heaters, water tank is not back a big, small, without preheating, i.e. open, pour the characteristics and features similar gas water heater. But this water heater power usually in 4-6kw above, operating current of up to 18-27A, beyond most residential can bear's current 15A. In addition, the unit will also effect regardless of size, use a greater limitations. market also difficult to see.
Early water storage-type electric water heater is open or open type. This water heater structure simple, the volume is not too large, hanging in the high pressure water spray, water flow is relatively small, but the price is cheaper, is suitable for small populations, the family was not wealthy, do only use family buy bath. Open-type electric water heater because no internal biliary design bearing performance, it cannot be more than the other lines, limited water supply.
Closed when the water heater water tank are sealed tank pressure greatly. This water heater tank can withstand, multi-channel water supply. Can be used for both shower and bath, can also be used for laundry, washing dishes. Water storage-type electric water heaters with thermostatic insulation performance, power failure so you can supply hot water. The bulk of the closed water heater can also supply center, a domestic supply multiple use of water.
Closed water heater prices relativelyexpensive, usually in the thousand or so. The unit of volume in General is large, bathroom smaller family should not install the bulk of the water heater. Closed water heater has an easy enough that the need to preheat before use.
2, according to the inner select closed electric water heater
Electric water heater tank must have insulation, resistance to pressure, rust-proof, anti-corrosion, waterproof, and other properties, the tank is the heart of the water heater, water heater once damage was reported. Tank of life depends mainly on the materials and manufacturing process.
At present the Mall sold water heater mainly has following several tank: galvanized steel tank: zinc protection layer is 0.06mm, vulnerable to rust.
Stainless steel inner: good, not rust material, but hidden keylogger welds, several hot liking, of chromium in stainless steel will be tap water in chloride ion etching, a long time after the welding point leakage.
Hot-dip zinc coated rust-proof resin tank: the tank forming galvanized, zinc alloy protective layer is above the surface and then 0.7mm feasible coated rust-proof resin. The inner life is also limited. Enamel tank: the tank surface enamel for non-metallic materials, does not rust, corrosion resistance, to do with thick steel plate, with strong resistance to pressure. Where high glazed steel tank corrosion resistance, insulation, delivered the best performance for longer life.
3, electric water heaters have a round, well, that's good?
We know that the application is round cans shape. Round cans of water heater can force uniform, high pressure, low production costs, the same size of the smallest of its surface area, or at least, it's superior to square a circle. Internationally famous electric water heater for round cans-shaped design.
4, according to their need to select a heater capacity
Electric water heater capacity general population according to the family, the room size and the meter circuits. In General,the family bought 3 of 40-50 liters. But if power lines allowed, larger room, install larger is better.
Closed water heater generally have automatic temperature control device, open water heater temperature does after falls below a specified temperature. Water heater capacity is big, the insulation of a long time, can be a lot of people have continuous bath, ad, not like small-capacity water heater that hot water is not enough, when the water temperature is stable with water. Therefore, conditional family best equipped with larger storage water heater.