Dustproof Enclosure for Remote Hitachi SJ200 VFD Control Panel?

[Chips O'Toole]

Not sure if this is "electrical," but...

I have a Hitachi SJ200 VFD on my belt grinder. Today I noticed the potentiometer knob had come off the control panel, which detaches from the VFD and is remotely mounted using a CAT5 cable. I tried to control the grinder using just the shaft, but the shaft was messed up. I was about to order a new remote when I decided to pry the control panel apart to see what was wrong. I found I could repair the potentiometer, which was somewhat amazing given the low quality of the part. Now all I have to do is find the knob, which is surely on the workshop floor somewhere.

Having dodged a $75 bullet (cost of a new panel), I now want to put the panel in some kind of enclosure to protect it from getting bonked again. I also want to keep dust out of the pot.

I'm wondering if anyone else here has tried this with a Hitachi SJ200 or similar VFD. Hitachi sells a "NEMA 4X kit," which appears to be a plastic frame that goes around the panel. It's ridiculously expensive. I'm thinking maybe I should make something for myself.

 

[uncle harry]

Not sure if this is "electrical," but...

I have a Hitachi SJ200 VFD on my belt grinder. Today I noticed the potentiometer knob had come off the control panel, which detaches from the VFD and is remotely mounted using a CAT5 cable. I tried to control the grinder using just the shaft, but the shaft was messed up. I was about to order a new remote when I decided to pry the control panel apart to see what was wrong. I found I could repair the potentiometer, which was somewhat amazing given the low quality of the part. Now all I have to do is find the knob, which is surely on the workshop floor somewhere.

Having dodged a $75 bullet (cost of a new panel), I now want to put the panel in some kind of enclosure to protect it from getting bonked again. I also want to keep dust out of the pot.

I'm wondering if anyone else here has tried this with a Hitachi SJ200 or similar VFD. Hitachi sells a "NEMA 4X kit," which appears to be a plastic frame that goes around the panel. It's ridiculously expensive. I'm thinking maybe I should make something for myself.

Perhaps you could modify a HVAC control enclosure and seal off the vents for this. That is if they are less expensive.

 

[Karl_T]

here's one I built

VFD control box

Here’s a nice little project. I built an enclosure to hold a VFD and controls for my son’s new (to him) lathe. The unit is built so he can just wire 220 1 phase to the VFD and then the 3phase lathe wires to the lathe on the output side. If (when) he trades up in lathes, the box comes right off...

www.hobby-machinist.com

 

[RobertB]

I'm wondering if anyone else here has tried this with a Hitachi SJ200 or similar VFD. Hitachi sells a "NEMA 4X kit," which appears to be a plastic frame that goes around the panel. It's ridiculously expensive. I'm thinking maybe I should make something for myself.

Hitachi's Nema 4x kit includes a keypad without the potentiometer, that's why it is expensive.

 

[Chips O'Toole]

I already have the VFD in a box. I just want to put the control panel in one. I want to be able to see the LED display in the box, and I want to put remote controls outside the box, since I will not be able to touch them once they're enclosed. If I could figure out how to make a remote LED display, I'd really be in business. I could put the priceless Hitachi panel away for safekeeping and use whatever I rigged up.

I got a price on a little plastic Hitachi frame to go over the panel: $84. Needless to say, I will not be buying one.

I'm looking at the manual, trying to figure out if I can use remote switches and a remote pot for the panel. If I can do that, I can put the panel and display in a box and put dust-resistant controls outside the box. It appears that I need a programmable logic controller. Maybe. Not sure yet. I know a little about electronics, but figuring this out will take time.

I only found one vendor who sells remote Hitachi keypads without potentiometers. The price: $220. That's not far from what I paid for the VFD. I assume Hitachi never actually sells any of these parts. They must be nuts. If this VFD poops out, I'm going Chinese next time.

This has been an informative experience. I never realized how badly VFD makers stick it to consumers. When I bought my first Hitachi, I blew it up by miswiring it. Hitachi told me I could not get parts to fix it. Since I've been researching the keypad problem, I've learned that all sorts of parts are available, so I blew $300 on a second VFD when I might have been able to replace a part. I have also learned that Hitachi does not support its "old" products, and when you are lucky enough to find a part for a decade-old VFD, you will pay an obscene price.

Seems to me it all adds up to one thing: buy Chinese. If I'm going to have a disposable VFD, I might as well pay an appropriate price. I can get a new Huanyang for $140. There is absolutely no reason to go with a "quality" manufacturer until they start treating customers a little better.

 

[JimDawson]

Why not do something like this. I built this for my mill remote VFD.

 

[Chips O'Toole]

I think that's about the best I can do without surgery on the keypad. It looks like it's not easy to add a remote 7-segment display.

 

[JimDawson]

I think that's about the best I can do without surgery on the keypad. It looks like it's not easy to add a remote 7-segment display.

Are you just trying to see the display? How about a clear cover for the VFD? It would be possible to add a panel meter to control panel, and use the frequency output from the VFD to drive it. But I think that is overkill for most applications.

 

[Chips O'Toole]

The thread is getting long, so some facts are slipping into the cracks. I should restate some things. The display and control panel are one unit, which the manual sometimes refers to as a keypad, and it is mounted remotely, beside the belt grinder, at the end of a CAT5 cable. The VFD itself is in a sealed steel box under the belt grinder. The keypad is out where dust and accidents can get at it. It's very fragile, and replacements are only available at predatory prices.

I originally bought the VFD for a lathe, and I didn't know anything about dust protection. I decided to use it with my belt grinder instead of shelling out $350 for a dustproof VFD. This is why it's now in a steel box.

I would like to fix it so I don't have to worry about the keypad getting damaged. If I put it behind clear plastic, I will be able to see the display, but I will not be able to touch the controls. It looks like it's not hard to create a remote panel with buttons and a potentiometer (actually a rheostat), but including an LED display on that panel would be difficult because I would have to find a way to connect it to the VFD. It probably has a flat ribbon connecting it to the board inside the keypad, and I doubt there is any easy way to add a second display.

I might be able to find some kind of cheap AC frequency meter for a second display. I could set it up so it gives me the frequency going through the motor wires. All I really need to see most of the time is the frequency. I was kind of hoping to program a constant into the VFD so it would multiply the frequency by it and read out SFM, but that won't work if I use a frequency meter.

It's starting to look like the simplest answer is to put the old keypad in a box behind clear plastic and rig up remote switches and a rheostat on the outside of the box.

I can open the keypad up and see if it's simple enough to replicate from individual components. If there is some kind of EEPROM or something in there, I don't see how I can replicate the keypad, but for all I know, it's just a few simple parts. If that's the case, I can put a new one together and run the CAT5 cable to it.

The Hitachi keypad is a disgraceful piece of junk. I don't believe it's made to stand up to prolonged use. I think it's the weakest link in the whole system, so replacing it with a homebrew version would be a great thing.

 

[uncle harry]

The thread is getting long, so some facts are slipping into the cracks. I should restate some things. The display and control panel are one unit, which the manual sometimes refers to as a keypad, and it is mounted remotely, beside the belt grinder, at the end of a CAT5 cable. The VFD itself is in a sealed steel box under the belt grinder. The keypad is out where dust and accidents can get at it. It's very fragile, and replacements are only available at predatory prices.

I originally bought the VFD for a lathe, and I didn't know anything about dust protection. I decided to use it with my belt grinder instead of shelling out $350 for a dustproof VFD. This is why it's now in a steel box.

I would like to fix it so I don't have to worry about the keypad getting damaged. If I put it behind clear plastic, I will be able to see the display, but I will not be able to touch the controls. It looks like it's not hard to create a remote panel with buttons and a potentiometer (actually a rheostat), but including an LED display on that panel would be difficult because I would have to find a way to connect it to the VFD. It probably has a flat ribbon connecting it to the board inside the keypad, and I doubt there is any easy way to add a second display.

I might be able to find some kind of cheap AC frequency meter for a second display. I could set it up so it gives me the frequency going through the motor wires. All I really need to see most of the time is the frequency. I was kind of hoping to program a constant into the VFD so it would multiply the frequency by it and read out SFM, but that won't work if I use a frequency meter.

It's starting to look like the simplest answer is to put the old keypad in a box behind clear plastic and rig up remote switches and a rheostat on the outside of the box.

I can open the keypad up and see if it's simple enough to replicate from individual components. If there is some kind of EEPROM or something in there, I don't see how I can replicate the keypad, but for all I know, it's just a few simple parts. If that's the case, I can put a new one together and run the CAT5 cable to it.

The Hitachi keypad is a disgraceful piece of junk. I don't believe it's made to stand up to prolonged use. I think it's the weakest link in the whole system, so replacing it with a homebrew version would be a great thing.

I use Automation Direct GS2 VFDs on my 3 phase loads. These units have a programming code option to use either the control panel pot OR a remote pot. Perhaps your unit will work that way as well.