3 phase inverter

[Phil C]

Learned sages, My neighbour asked me to get an inverter for his 3 phase 3kw compressor. We have 220v 50cyc in France. I bought an inverter, 4kw, thinking it would be 'plug n play' Ha! Much to learn! The inverter is an Isocon A2 unit.
Can anyone supply the settings for this motor please?
I have the manual, but it's not clear.
Thanks, this is the motor plate.

 

[plugwash]

Can you be more specific as to what exactly you bought, googling "isocon A2" doesn't seem to be giving me relavent results.

 

[Phil C]

Sorry, not enough info. It's made by Isacon Power Control tech, model A2

 

[Nozzle]

What you've bought there is a VFD - you could still use it to run the 3 phase motor though, but with the added complication of having to figure out how to soft start it.

http://www.et.byu.edu/~sorensen/A2 VFD Manual.pdf

Nozzle

 

[Phil C]

Thanks Nozzle. I'm aware it's an inverter. It's help with the settings I'm after. As I said, I have the manual, but can't work out the settings.

 

[Nozzle]

You've used the term Inverter and I've used the term VFD. They aren't the same thing.

I suggest you disconnect the drive belt from the compressor and hook it up from there, start with running it unloaded. The compressor should (will) have a mechanical unloader anyway so should unload the cylinder when it stops, and then build up pressure again when it re-starts. What you have to be wary of is that the motor gets up to enough speed to then not stall once the mechanical unloader goes to reload.

Unless there happens to be someone with the same motor, compressor and VFD combo using this forum, then no-one will be able to give you settings that work right out of the box. Trial and error my friend.

I have provided a link to the manual so other contributors don't have to guess, as I had to guess.

Nozzle

 

[ericmark]

As @Nozzle says there is normally a de-loading valve, worked as the compressor goes star to delta, but reading the plate, it seems likely direct on line, so some other method of de-loading.

 

[Nozzle]

As @Nozzle says there is normally a de-loading valve, worked as the compressor goes star to delta, but reading the plate, it seems likely direct on line, so some other method of de-loading.

A 'domestic' (read single phase?) compressor unloads as soon as the pressure switch hits the top stop, or the off/auto button is pushed.

Nozzle

 

[ericmark]

A 'domestic' (read single phase?) compressor unloads as soon as the pressure switch hits the top stop, or the off/auto button is pushed.

Nozzle

It is three phase, but most three phase are 400/695 volt, the 695 volt star used to start it, and 400 volt run, but this one is 230/400 volt so 400 volt star and 230 volt delta, so most motor inverters would use the 230 volt delta input to motor, and some sort of soft start, so some inverters do have a switch which makes when at full output, but not all, and I don't have the details of the inverter being used, in general we are looking at an expensive bit of kit, around £400 worth, and will likely need a 32 amp supply. The instructions can be easy a 400 page document, and every make is a little different.

In the main I would ring the supplier and their rep would recommend which drive to use, SWF had the drive built into the motor, also Asii control so tended to go for them, but it is not easy, and I did make errors, and so easy when trying to make some thing do, costing more than buying the right motor and drive for the job.

 

[fixitflav]

Learned sages, My neighbour asked me to get an inverter for his 3 phase 3kw compressor. We have 220v 50cyc in France. I bought an inverter, 4kw, thinking it would be 'plug n play' Ha! Much to learn! The inverter is an Isocon A2 unit.
Can anyone supply the settings for this motor please?
I have the manual, but it's not clear.
Thanks, this is the motor plate.View attachment 237726

Just for curiosity, why does he want an inverter (or VFD)? Assuming the compressor is currently in use, how is it started now?