Does the electric fire pump have overload protection?
Thread Content
The situation is like this. Our newly built refined oil tank farm is another refinery that provides fire-fighting water. Later in the local * * During the inspection, it was believed that the fire protection system of the original refinery could not ensure the safety of the newly built tank farm. Therefore, the design institute added two new pumps, one electric pump and one diesel pump, which were integrated into the original fire protection pipe network. The rated flow rate of the pump is 1,200 cubic meters per hour, and the head is 121 meters. Because the pressure of the original pipe network is relatively low, only about 6 kg. The design institute's data sheet states that when the system pressure drops to 5.5 kg, the electric pump automatically starts ； When the pressure in the pipe network system drops to 4.5 kg, the diesel pump starts. I am now worried that if the rated pressure of the pump is 121 meters, then when the system pressure drops to 4.5 kilograms, that is, before the diesel pump starts, the current will be at least twice the rated current. If the electric fire pump has overload protection, the motor will stop spinning long ago, which will have an impact on the normal operation of the fire protection system.
How did you calculate the current value?
1. The fire pump must have overload protection. 2. You don’t seem to understand the functions of the electric pump and the diesel pump. Take a closer look at fire protection design.
This is estimated based on experience.
first question: If there is overload protection, is there any standard that stipulates the limit of overload protection, such as 300% of normal current or 200% of normal current? Second question, I understand what you mean and the role of electric pumps and diesel pumps in general. The problem is that the pumps we have here are compatible with other refineries. According to the design intention, when a fire occurs, our main electric pump starts, and then the two electric pumps in the refinery (each electric pump has a rated flow of 600 cubic meters per hour and a rated lift of 6 kg). If there is a power outage, our diesel pumps start, then the refinery's two diesel pumps. Since the two electric pumps in the refinery are in disrepair and cannot be relied upon at all, if our deluge valve and foam skid are started at the same time (water demand is about 2,500 cubic meters per hour), one electric pump can only reach half of the designed flow rate. At this time, it is likely that another diesel pump will be activated.
Pump ------ idling, dry pumping is recommended to install a pump anti-idling protector, which will automatically stop within 2 seconds when idling, to protect the pump from damage Electronic sample address: http://www.dnpump.com/PicUp/200910162202501.pdf If you want less maintenance, choose the matching anti-aircraft dry-rotation protector to save trouble.
UL or FM certified motor fire pump control cabinets do not have motor overload protection. However, when selecting a fire pump, the capacity of the motor is required to ensure that the fire pump can operate at any point on the pump performance curve.
Electric fire pumps should have overload protection, and all electrical appliances should have it.