November 12th, 2018
When starting any pump or working with any pump control system, whether the pump be a VFD pump, or an HVAC pump in New York being driven by a drive or an across-the-line starter, it is very important to know the basics first. Number one, make sure the water is onto the pump. If the pump and motor are coupled in the middle, called flexible coupled, make sure the two are aligned. You must make sure that motor end and the pump end are between 5-7 thousandths aligned directly to each other through this at least with a dial indicator, if not laser. When you do an alignment, you must make sure the pump is installed, that water is in the pipe, that the pump has been settled. Do the alignment and then grout the base.
The very next step would be to check the rotation of the pump. In New York City, we were sent to 15 different Manhattan mini-storage units to make sure that pumps were being tested properly. 3 of the 15 pumps that were in operation for over 20 years were running backwards. These same pumps “passed” their flow test. In reality, they did not pass the test; they were not being tested correctly. Callaghan Pump does not lie on our tests of pumps and pump control systems. Pumps either pass or fail; we don’t cheat. Many companies either do not know how to test properly, or fill out the paperwork from the previous year and send it on.
Always make sure rotation is correct, that’s vital. If it is a fire pump, and you get rotation set correctly, you must check if there’s a transfer switch. Make sure the pump rotates the correct direction when it is being fed by the generator, the backup power. These are the basics for all VFD driven pumps. You can change rotation in the drive itself; there is no need to change the wires. This is true of Yaskawa drives; it’s a simple, fast fix. If you are using a starter, you have to physically change two wires. With regards to fire pumps, once you set the rotation and tell the controller the rotation is correct if the power supply gets cut or is hooked up backwards, it will set a phase reversal alarm. These are just a few basics of pump control systems. There are many others. We will follow up in future articles.