Wide Belt Sanders and Phase Converters

Stepping up to a large widebelt and three-phase power brings a big boost in capacity and efficiency. January 1, 2012

I am a two man shop with limited space. I want a 37" wide belt sander without question, however, my small shop only has 100 amp service, single phase (terrible, I know). It will cost approximately $1000 - $1500 to upgrade to 200 amp service, which I am okay with, except that you have to have permission from the power company in writing, which they will not give me at the moment. Also, I am planning on remodeling and adding on to the shop in approximately 1-2 years and will have to have an electrician come in at that time anyway. I've looked at phase converters as well, but again you have to have permission. So I am considering the following options.

I've found a 37" single phase wide belt sander with a 70 amp pull, but my dust collection is a 30 amp pull and at 100 amp service I don't think I want to push that. It also has pneumatic tracking at 75 psi, so if the compressor kicks on, I would be well over 100 amps.

I could go with a smaller wide belt sander with a 30 amp pull. The 24" is right at that and so is a 15" open end, so 30 for the sander plus 30 dust collector and 30 air compressor leaves me at around a 90 amp load... Pushing it, but I feel comfortable with that. The only thing here is I am losing the capacity to run wide parts through (face frames). Should I be running my face frames through anyway?

But the 24" would be fine for doors, as 99% of my doors are under 24". As far as an open end, I'm not sure those things would be accurate.

My third option is to just get a 37" drum sander. It has a 50 amp pull, and 30 for the dust collector puts me at 80 amps, so I would be safe because I don't have to think about the air compressor. I would really rather have a wide belt but given my circumstances, I don't know if it is the right thing to do.

Forum Responses
(Cabinetmaking Forum)
From contributor E:
Most of the amp draw is at the machine startup. To max out your power, you would have to start everything at the same time. Your sander would probably only draw 20 amps running. Your air compressor draw is probably a third of its listed amps. Consult an electrical engineer.

From contributor J:
I agree that consulting someone who really knows electrical would be prudent.

I'm in a not-too-different situation. I have a 3 phase 100 amp panel in my shop. My 43" sander has a 25 hp motor at 63 amps. My 7-1/2 hp dust collector is 20 amps, and my compressor is only 5 hp, so about 14 amps. They all run at the same time without any issue. I do start the sander first and wait until it's up to speed before starting the dust.

I also take light passes and watch the meter while sanding. I try to keep it from going much over the 50-60% range.

I would always go bigger when it comes to a sander. As long as it fits within your power limitations, you'll never regret having the width or extra power.

From contributor M:
Highest amp draw is at startup, so you should be fine. I would advise you to stay away from a pneumatic tracking sander, though, unless you are running a screw compressor. Almost all sanders switched to electronic tracking for a reason.

From contributor K:
You need permission to put in a phase converter? I didn't know that was required.

I once was in your situation, underpowered and no widebelt. I got a 37" with electronic tracking a year and a half ago. You know the feeling of "why didn't I do this earlier"? It is like that all the time. You'll never regret spending money for at least a 37". You will regret getting a 24". 99.9% of everything I make goes through the widebelt. 12 foot long island panels - through the widebelt. Big ass fridge panels - through the widebelt.

Only face frames that are wider than 36" and are taller than 36" have to get pre-sanded. Since I'm designing most of my kitchens, I make sure that doesn't happen. A widebelt will trim gobs of time off from production and produces a better product. It will pay for itself very quickly. Quicker production puts more money in your pocket.

From the original questioner:
Thanks for the responses. I followed your advice and did speak with an electrician, and he agreed that the list amp draw is mainly at startup and under heavy loads. So I am just going to go ahead and get a 37" wide belt. I agree that I won't regret the larger capacity.

As far as pneumatic tracking goes, I'm a little confused on what contributor M said about a screw compressor. What are the main benefits of electronic tracking? I ask because the single phase sander I'm looking at is a Grizzly G0571 and is a cheaper sander and has pneumatic tracking.

However I think I'm just going to try and get permission from the power company for a phase converter and go with something used in my area. Everything I've seen on Craig's List, EBay and the like are 3 phase with more power and more than likely electronic tracking. Although I'm going to need to research phase converters a little more as far as power requirements go. I'm aware that you need at least double the HP rating of the machine you're running, and the amp draw is high at startup, but idle is low. So when it comes to how the unit works, does it kick on when it needs to like a compressor, or will I be able to turn it on, let it start up, let the amp draw go down to idle, then turn on the dust and then the sander? How would that work?

Contributor K! Hey there. Kind of ironic really that I meet you here. You don't know me but a big part of why I build my stuff the way I do is because of you. When I was first learning I came across your videos and they have had a big impact on the way I do things. And yeah, they do require you have permission in my area. Kind of overkill in my book, but what can you do? One thing I've always wanted to ask you is how has the Grizzly machinery held up for you? I noticed you had some Grizzly stuff in your videos.

From contributor K:
Thanks for the nod! My Grizzly stuff... It was good gear for getting started, I'll say that much. I added a spiral cutterhead to the jointer and planer which helped a bunch. The shaper and edge sander are okay at best. I am, however, in the process of slowly replacing my Grizzly equipment with heavy duty industrial equipment. Since putting in a phase converter (I got one from Phoenix Converters), options for equipment have gone way up. I plan on adding a 7 1/2 hp shaper, a 12" jointer and a slider.

My widebelt is a Butferring. I got it used for less than the price of a new Grizzly. I too looked at the Grizzly widebelt when it was time, and had a lengthy discussion here. That convinced me. Single phase motors (to my understanding) cannot be more than 5 hp. That's true horsepower. Yeah, I have a Porter Cable router that is 3 hp. Is it really? Nope. When you step up to 3 phase that's when you're getting what you pay for. 3 phase industrial machinery runs on half the amperage of single phase, is very powerful, very heavy, and incredibly reliable. I'd personally spring for a digital readout and automatic table lifting with electronic eye. I spent 11k for the sander, my phase converter with wiring, and a new compressor. Sounded like a ton of money at the time, but holy cow! Sanding time is way down. Everything goes through that thing.