Colchester coolant pump

I have just re-configured my coolant pump to delta connection in order to run it from a small inverter. How do I know it is running in the right direction? My initial thought is to use the flow rate, better flow = right direction. Am I on the right track?

Hi Martin I do not think it matters. In mine the flow point is central on the pump and it works in either direction. It's only a vane pump so no damage will occur.

Brian

Correct they are vane type and freely spin in either direction and would always push the coolant up the spout.

They are all dual voltage same as Harrisons and Boxfords, burnt three out within 8 months using same inverter to power the lathe. Hear reports of similar with static convertors.

I run my Bantam from a static converter not an inverter, the coolant pump is the original, and has run for 28 years, but not all the time of course. It is always started after the main motor is up and running and switched off before the main motor.

Chris Gunn

.

I have a 3 phase coolant pump motor running on my Boxford. It runs hot, very, very hot.! It's only a matter of time before it throws the towel in. Due to it's running temp I seldom use it.

Once it goes fubar I will get a 240v one.

Nick

Hi guys

thanks for the info

I intend to use a separate, dedicated inverter for the pump, so I think all will be well.

I run my Bantam coolant pump from the same VFD as the main motor. As long as you are running somewhere close to the nominal speed, like within +/- 50%, it operates OK. The flow obviously varies with the spindle speed but you can adjust it with the tap.

Generally speaking, if you are using coolant it probably means you are using some power in which case you should be in roughly the right gear and your motor should then be operating reasonably close to nominal.

As pointed out, the impeller is symmetrical, so it works equally well in either direction. At one point I had to dismantle the pump to free it up but otherwise it's pretty simple and looks almost bullet proof.

Murray

Now that the motor windings are configured in Delta why not connect two of the three connection to live and neutral. Then connect one of the capacitor leads to the vacant terminal and the second lead to either live or neutral. I can't exactly remember the capacitor value but think it is around 4 micro farads at 400 volts. I have done this arrangement for several friends and it works, no over heating or other problems. Ex fluorescent caps are ideal. You may have to play around a bit with cap values to get things quite right. I'm sure some one here ,will remember the correct cap values, its quite a well known idea. Forget running on an inverter especially at slow speeds. The motor will get hot as it is on load and rotating slowly.Ted

The dedicated inverter is to provide three phase and will be set at 50Hz with a remote switch for start and stop. I do not intend to use variable speed. The main inverter for the lathe is set to 50Hz as default and uses a remote signal to trigger a speed change to 100Hz. This gives me two speed ranges via the gears. In effect I have made a Bantam 800 into a Bantam 1600 without using a two speed motor. The capacitor idea gives me food for thought though and will be considerably cheaper.

Edited By Martin Peck on 24/11/2014 09:47:56

So would a new single phase pump compared to an separate inverter.!

Here is one :- http://www.ebay.co.uk/itm/Vertex-Coolant-Pump-240-volt-1-8hp-100mm-Stem-/291298603436?pt=UK_BOI_Metalworking_Milling_Welding_Metalworking_Supplies_ET&hash=item43d2bff1ac

Nick

Edited By Nick_G on 24/11/2014 09:57:30

Drives Direct have a small (1/4HP) inverter for £85, so pricewise there is little to choose between. I will try the capacitor method though when I find the right size capacitor.

You will find the Chinese ebay link ones way too short even at 180mm so would need the tank as well £161. Been there three times last 4 years and ended up with to get me out of the proverbial. They don't hold much either, have to keep fully topped up. **LINK**

That's the ball park for original motor rewind.

Hi all

I found a 2.5mf capacitor and tried it. Pump runs but sounds a bit rough. I guess it was the wrong value cap.

I have a small inverter arriving today from Drives Direct @ £100, will post results shortly.