Can the test pump be tested?
Thread Content
There are many versions of operating procedures for moving equipment. Some say that trial operation of the machine and pump can be carried out, while some versions specifically require that trial operation of the machine and pump is strictly prohibited in the safety points. Friends who are engaged in equipment, please tell me what you think.
The principle is that there is no medium in the centrifugal pump body and it must be idling strictly. In the case of medium, I personally think that the problem is not big if you try it out, and the time should not be too long.
When the pump starts, the starting current of the motor is quite large, usually about 7 times the rated current. Therefore, the outlet valve must be closed when the pump is started, and the pressure of large pumps must be reduced. Therefore, no matter whether the pump has medium or not, avoid "jogging" during trial operation.
What you want is to confirm that the point test method can be used to turn the pump. This is okay.； “It is incomprehensible to use spot testing for "test operation of machine pump".
My experience is based on the performance and requirements of the pump. Some can be ordered while others require caution or even prohibit the order. The unit's pumps are generally inspected for leaks after completion of maintenance, in case the pump cannot be opened when it is necessary.
Generally, when testing the steering of the motor, move it a little. Try not to move it normally to avoid damaging the machine seal.
Unspoken rules are allowed. Before the pilot test of a single-stage centrifugal pump, the pump must be primed and exhausted. After starting the pump, quickly check the leakage and temperature of each part and then stop the pump. Determine whether the standby conditions are met.
personal opinion: In the presence of medium, the small pump can be pilot tested, and the crankshaft should be checked before starting. Large equipment should not be tested due to difficulty in starting the motor. Generally, the motor should be fully started before shutting down to avoid damage to the power grid and equipment.
It is indeed necessary to check after actual maintenance or installation. It seems that this is not good.* It should be done according to the requirements of the pump's operating procedures, and you cannot try all pumps. Strictly follow the instruction manual to avoid mistakes. When testing forward and reverse rotation, the motor is usually tested separately. Only when it is correct can it be connected to the back wheel.
Whether to use spot testing should be decided based on the characteristics of the equipment and cannot be generalized.
When testing a pump, we usually turn on the power and then open the outlet valve. For pilot testing, we turn on the power and turn it off immediately. The rules for cranking without opening the outlet are that it is prohibited to pilot a pilot. Generally, pilot testing is prohibited, especially for the unit, otherwise it will be over. However, for general pumps, try not to pilot the pump as it will affect the service life of the pump.
For low-power pumps, you can test the direction of the motor by jogging. Generally, there will be no problem. However, for canned pumps, magnetic pumps, etc. that are strictly prohibited from idling, you should be cautious.