The low water level interlock protection signal source of the fuel oil wall-hung boiler comes from the water level control and alarm device, just like other wall-hung boilers using coal or gas. When the water level exceeds the limit, the water level control and alarm device should first perform a high and low water level ±50mm limit alarm to remind the operator to pay attention and handle it. When the water level is too low and reaches the low water level interlock protection level (-75mm), the boiler will then stop for interlock protection. During the shutdown process, the oil electromagnetic valve is turned off first to cut off the oil circuit, and the fan continues to blow for 20 seconds before stopping. After the low water level fault is eliminated, manual startup is required to resume operation. Since the fuel oil wall-hung boiler heats up quickly and the water level changes rapidly under large load variations, the sensitivity of the water level control and alarm device must be high, its operation reliable, and the water level control range appropriately selected.
Specific Description of Low Water Level Interlock Protection for Weima Fuel Oil Wall-Hung Boiler
Source: Beijing Weima Wall-Hung Boiler Repair http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3778832.