New inverter 1hp - bought cheap one now regret it

[fred55]

Given a Union Graduate lathe 3ph motor - bought a cheap inverter £65 from ebay (yes china), had roughly 15hours of use and the cooling fan is on its way out - its served its purpose of testing the machine and getting me hooked into wood working - So could anybody recommend a source or name of a "good" inverter, the motor is high or low (star/delta) by altering bars, 1hp. New or used any help gratefully received. There are so many on ebay but would like one to last this time.

 

[Presh]

I'm unfamiliar with the lathe you mention but know that, where possible, it is always better to try and purchase an inverter drive from the same manufacturer as the motor to ensure that there are no interface issues. I assume that the lathe motor has been specified for inverter use otherwise it may overheat and also assume that you know the turn-down ratio capabilities of the motor (i.e. 10 to 1 say) so you can select a suitable inverter.

 

[porker]

I have used drives direct to buy two inverters for my mill. Had a few initial issues (my fault) and they were very helpful in sorting me out.

 

[graduate_owner]

If it's just the cooling fan then you could perhaps do what I did when the fan on mine packed in. I mounted a cooling fan from an old computer power supply beneath the air vent of the inverter and connected it to a cheap mains power supply. Make sure it blows in the right direction. It went on for well over a year like that but has recently stopped, burnt out transformer and a couple of blown capacitors. The caps are not a problem but I can't get a matching transformer so I have just bought a replacement - a 3HP Invertec from ebay, made in UK. Less than £200.

Just a couple of points - mine needs to be protected from dust and excessive moisture. If any of you guys are using an inverter which is not suitably IP rated then it might be worth considering mounting it in an enclosure with fan assisted filtered ventilation, it's what I will be doing.

Secondly, the variable speed is brilliant but you need to be careful at low speeds because the cooling fan will be turnimg slowly as well, so not much draught through the motor. A separate cooling fan which stays at high speed could be needed.


K

 

[fred55]

thanks for comments - I like the idea of adding another fan !! worth a go gives me time to look into other options. - just sprayed a mist of WD40 and the squeaking fan is quiet ! this gives me time to check out what are the better types of inverter.

 

[Doug B]

I've used Transwave a couple of times in the past, I've found them helpful & they guarantee their products.

 

[graduate_owner]

Some more comments on inverters (you can tell I've been reading the manual this time!!). If they get damp from condensation etc then the components on the circuit board can be short circuited - the moisture causes tracking between the closely spaced components. So if you think you have a dampness issue, don't switch on until the unit is dry. Also, if you are producing dust, fumes or if you have the inverter in an atmosphere where gaseous chemicals could be blown in by the cooling fan, then that is asking for trouble. I was thinking, perhaps welding fumes? (which should be extracted outside anyway and not breathed in). Also metal dust from grinding could be an issue.

K

 

[Doug B]

Some more comments on inverters (you can tell I've been reading the manual this time!!). If they get damp from condensation etc then the components on the circuit board can be short circuited - the moisture causes tracking between the closely spaced components. So if you think you have a dampness issue, don't switch on until the unit is dry. Also, if you are producing dust, fumes or if you have the inverter in an atmosphere where gaseous chemicals could be blown in by the cooling fan, then that is asking for trouble. I was thinking, perhaps welding fumes? (which should be extracted outside anyway and not breathed in). Also metal dust from grinding could be an issue.

K

You basically need to protect your inverter dust cage, heater etc or buy one with the correct IP rating (ingress protection) for your own situation.
This page gives you the low down on IP ratings.

http://www.inverterdrivesystems.com/inv ... p-ratings/