Single to 3 Phase inverter delaying start

[OldWood]

I'll start by saying that I am reasonably comfortable about these inverters, having a wood lathe and an old Fobco Star drill running off them.

I am restoring a Cooksley 12" planer/ thicknesser and have a single to 3 phase 240v inverter made by a Chinese company called Isacon Power Control Tech.

I had a wee batle to begin with to get this to run as all its initial settings were for a 400Hz output and rather obviously I am wanting 50 Hz. Anyhow the motor is now running albeit without being attached to the drum. However try as I might I cannot find a parameter on this particular inverter that seemingly delays the motor start for 10 seconds - that is, press the 'Start' button on the inverter and nothing happens for what I am timing as exactly 10 seconds and then the rotor winds up as expected.

Can anybody make any suggeestions as to why it might do this - both my other two inverters fire up the related motor immediately ?

 

[ChaiLatte]

Do you have a manual for the VFD?

There is one here that looks a likely candidate:

https://www.et.byu.edu/~sorensen/A2 VFD Manual.pdf
PN16 Startup DC braking time might be worth investigating.

 

[Spectric]

seemingly delays the motor start for 10 seconds

look for ramp up time, it is used to reduce the inrush load on the supply and acts like a softstarter.

 

[Fergie 307]

Sometimes the Chinglish instructions can be fun to try and work out. Mind you their English a lot better than my Mandarin

 

[OldWood]

Thanks ChaiLatte - That's the handbook I have. My records from today's work show that PN16 is at 0, but it might be worthwhile trying to change that to see if it effects what I am finding. Tomorrow's experiment!!

Rob

 

[OldWood]

Well that is one of those embarrassing moments that you just cannot explain!!!

Yesterday I had gone through all the parameters noting them down against the applicable row in the manual - and had written 0 against PN16. I can only blame that as a brain fart as when I went back into look again this morning it was set for 10 seconds. I'll try blaming the gremlins but really that does look like some sort of goolly in my part.

Many thanks ChaiLatte for sending me in the right direction.

Spectric - the ramp up time is "Acceleration Time" and I've set this to 5 seconds - this will be the rise in the drive frequency and power. Once on load I think I will increase that to 10 as the Cooksley has a three blade drum.

Fergie307 - the Chinlish isn't bad at all, with the one exception I spotted in the 'Environmental Conditions' - "No floating dust or mental particles". I am prepared to suggest that maybe I was missing one or two of the latter yesterday.

Thanks all
Rob

 

[Sideways]

I have a big saw set for a 10 sec ramp up. It sounds impressive listening to it just keep getting faster and faster. Like a jet spinning up
But it's a teeny bit tedious in use. Try your planer at 7 and 5sec ramp with a clamp meter and if the current stays manageable I'd choose one of those.

 

[ChaiLatte]

Try your planer at 7 and 5 sec ramp with a clamp meter

What is the purpose of the clamp meter?

If the ramp time causes the overcurrent setting in the VFD to be exceeded, the VFD will fault out. If it does not, it won't. Seeing a number on the screen of a clamp meter will do nothing to change that.

 

[OldWood]

ChaiLatte
I think the point is that on a cold day the current may be just be that little bit higher that trips the VFD. I would go with Sideways suggestion - and thank him for it - as it would be better if the margin isn't tight. That is better on the frustration front of not having to do the reset of the parameter as the VFD will protect itself as you say.

 

[Sideways]

Only @OldWood will know exactly what combination of loads he's likely to have in his workshop vs the fuse / breaker capacity, and for that matter the likely loads in the house if it's a domestic setup with a workshop spurred from the house consumer unit. We get away with bigger machines in a domestic setting by working within the limits of our supplies.

We also tend not to push our machines the way they would be in industrial production. I'd be surprised if most of us get anywhere near the motor full load current we designed and installed for and programmed into the VFD.

In deciding how fast to ramp up the machine, startup current may be of interest and if you happen to have one sitting there, especially the type that will capture startup surges, a clamp meter is simply an easy way to observe this. Change the ramp time and see what effect it has on the current. Find a compromise that doesn't keep you waiting but doesn't dim the lights either
Yes, the VFD can probably be set to display Amps. A clamp meter (some of them cost more than a VFD) may be better at capturing and displaying the surge. It's not a big deal but if you have one, why not use it ?

One thought prompted by this though is to remember to set the VFD for the appropriate application. On the Invertek drives that I tend to buy, if you set the relevant parameter to "general", the VFD default allows a 50% overload for 30 seconds - that suits saws and planers well.
If you accidentally set that parameter to "fan or "pump" then the overload profile is very different to better suit those applications. The VFD will allow you upto 10% overload for years on end, but the moment you hit the limit it will trip out instantly. It's surprisingly easy to hit a 10% overload limit on a machine subject to varying loads.