[NathanG34]

Hi guys,

I’ve been building my first CNC slowly over the course of this year and everything has been going pretty well overall, I’ve browsed CNC Zone regularly but haven’t really needed to post about anything before. However, more recently I’ve run into an issue when trying to run my spindle. I’ve got a Hitachi 2.2kW WJ200 and a Chinese 1.5kW spindle from solar.jean on eBay. I’ve wired the spindle into the VFD with a 4 core cable (not completely sure of gauge). Here are pictures of these:

Attachment 262134
Attachment 262136

I originally followed the WJ200 manual to setup the VFD by setting the four basic parameters of base frequency (400 Hz), AVR voltage of 220V, number of poles (2), and the motor current limit to 5A, all based on the motor nameplate. The first time I ran the motor, it started up and accelerated to 400Hz seemingly fine, but after about 20 seconds the VFD tripped an overload protection error (E05.3). The WJ200 manual says: “E05 - Overload protection - When a motor overload is detected by the electronic thermal function, the inverter trips and turns OFF its output”, and the .3 means the trip occurred at constant speed.

I downloaded Hitachi control software (ProDrive Next) which lets you plug into the VFD via USB, and this was the output from startup of the spindle until it trips:

Attachment 262138

This shows the input to the VFD from mains, the current draw is only 2A at 250V (this is in Australia, which is why it's ~240V).

Attachment 262140

Do these numbers make sense? Does anyone have any suggestions as to what I can look closer at? I’m not sure how to debug this short of buying a new spindle/new VFD to see what works. Is there any testing/inspection I can do on the WJ200 or the spindle to figure out why it is drawing over the FLA with zero load?

If anymore information would help, let me know.

Cheers!

[untametycoon]

Experiencing this problem with a 2.2kw huanyang and hitachi NE-S1. Did you solve it?

[dmannock]

There are 2 possible issues that are worth looking at: 1) What is the power outout of your VFD compared to your spindle do you have enough extra power? Remember that a 1PH to 3PH VFD may need that extra headroom. 2) Some cheap VFDs have only rudimentary monitors of the signalling and power circuits. There are relatively cheap phase/voltage monitors available which can be added to a DIN rail to help with these problems. PMRU-1C-480A

[NathanG34]

Hi,

I tried a fair few different settings in the driver software for the WJ200, but I think what really 'solved' this was actually setting up water cooling. I had wrongly assumed that water cooling was only really required for long term use, but as far as I know the motor heated up within about a minute after which the overcurrent protection would trip. After tripping the first time it would then trip in about 15 seconds thereafter ie. after it had heated up it would trip faster. After setting up water cooling, I may have then disabled current protection. My assumption here is that as long as water is flowing the current protection isn't absolutely necessary. The life of my motor could potentially be reduced, however I guess it was either that or buy a new motor anyway (assuming the motor is at fault).

This is what I received from a support person where I bought my motor from:

"The drive is doing exactly what is asked of it.
VFD is out putting a voltage. The motor is demanding the current.
Drive see's current over set limit and goes into current restriction at the B022 setting or 7.5 Amps."

In other words, the motor will draw the amount of current it requires, and if the drive detects current draw above a set limit it will stop to protect the motor from heating up/melting. My counter was cooling it down with water as recommended.

I've been able to cut for about 2 hours of continous runtime with water cooling now, and have done a number of projects with this setup.