Question about rewiring machine to 240

[Barry Lyndon]

First, I've never rewired a motor from 120 to 240 my questions may seem obvious to some... I have a Rikon 10-325 Delux 14" bandsaw that I am rewiring for 240v. I feel like I understand everything but when I started stripping the new cable and running it through the machine and connecting it I noticed that something seemed wrong. When I went to home depot to buy everything I needed I asked if the guy working in electrical knew what wire I needed and he immediately said 12-3 so I got 8 ft. of the stranded 12-3 black wire. I also got one of these http://www.amazon.com/Leviton-2321-L...ef=pd_sim_hi_2

The wire seems to be too big for the plug (the clamp is very tight on it) and the wire is definitely too big for the plastic pieces keeping the cord in place throughout the machine. Did I get too big of wire? I always read that with 240 the amperage is smaller so you can use a smaller wire but I didn't know if that meant on the machine too. The machine says it's amperate is 14/7 which I assume means 7 amps using 240v. Is there a chart or rule of thumb as to what size wire to use depending on the amperage of the machine or should a certain size always be used for the plug wired to the machine?

[Mark Ashmeade]

The term is "ampacity", the current capacity of a conductor. Note that voltage doesn't come into play. Amps are what matters to cable. This is true up to several kV.

Here is a table of ampacity http://www.powerstream.com/Wire_Size.htm

For a 7A machine, 12AWG is sufficient (to the point of overkill). Even at 14A, 14AWG would have sufficed. 12AWG will be perfectly adequate, but as you have noticed, the larger cable has physical restrictions.

However, the big red flag for me is 12-3 cable. Your bandsaw likely requires two conductors and an earth(ground). This is commonly called 12-2. 12-3 would be required where the equipment requires a 120v feed as well as the 240, eg for a light. It has an extra conductor for the neutral. As above though, 12ga is overkill. I'd look for 14-2. That said, flexible stranded cable is available in a myriad of styles.

Any reason you couldn't use the original cable?

[david brum]

Are you sure your wiring diagram calls for 4 wires? My 220 machines all use 3 wires (2 hots and a ground). I think you'll find that 12-3 wire also won't work with your plug (it has attachments for 3 wires). How is your outlet wired?


You can definitely use 14g wire if you're only pulling 7 amps. That leaves you plenty of leeway.

[Barry Lyndon]

Are you sure your wiring diagram calls for 4 wires? My 220 machines all use 3 wires (2 hots and a ground). I think you'll find that 12-3 wire also won't work with your plug (it has attachments for 3 wires). How is your outlet wired?


You can definitely use 14g wire if you're only pulling 7 amps. That leaves you plenty of leeway.

However, the big red flag for me is 12-3 cable. Your bandsaw likely requires two conductors and an earth(ground). This is commonly called 12-2. 12-3 would be required where the equipment requires a 120v feed as well as the 240, eg for a light. It has an extra conductor for the neutral. As above though, 12ga is overkill. I'd look for 14-2. That said, flexible stranded cable is available in a myriad of styles.

Any reason you couldn't use the original cable?

Actually, when the guy told me that I needed 12-3 I told him that I only needed 12-2 but then he "corrected" me and told me that the ground wire (green) counts as one of the wires in this type of cable and it's only called 12-2 when referring to Romex cable. I don't remember what type of cable this is, but it's what is sold at Home Depot by the foot. It's black, 12 guage, and stranded with really thick outer insulation cover. Anyway, maybe this guy didn't know what he was talking about. The wire that I have does only have 3 wires - 2 hot and a ground. The outlet is wired with 12-2 romex.

As for using the original cable...I guess I didn't realize that was okay to just snip off the original plug and put a different one on. After discovering how big of a hassle it is to change out the cables (especially when using one that is too big), I will definitely be using the original next time I do this if I can. Actually, since I now have none of the plastic screw together pieces that hold the cable in place on the machine because the cable was too big for them I will probable just take it back apart and use the original. It seems dangerous to have the cable only connected to the machine where it is screwed into the switch especially with a plug that locks into the wall.

Thanks for the help as always guys!

[Rod Sheridan]

Barry, you are correct that when purchasing cabtire the ground conductor is counted in the description.

It's a good idea to put the box connector back on to hold the cabtire to the switch enclosure, in fact it's required by code.

I had to chuckle when I read your post, converting from 120 volts to 240 volts allows you to reduce the corg gauge, you actually increased. On the plus side you certainly won't have any voltage drop issues.......regards, Rod.

[Curt Harms]

I did the same with my Rikon 10-325. I've never had much luck with the plastic 2 piece "box connectors" found on Asian woodworking machinery. I just replace mine with standard box connectors. I guess if you were really paranoid about dust getting in the connections/capacitor box you could use a liquid tight connector. I think you'll find out that if you have a dust collector-not a shop vac- the dust collection is very good. Not perfect but very good. There's no dust around the motor area to speak of.

[Barry Lyndon]

I did the same with my Rikon 10-325. I've never had much luck with the plastic 2 piece "box connectors" found on Asian woodworking machinery. I just replace mine with standard box connectors. I guess if you were really paranoid about dust getting in the connections/capacitor box you could use a liquid tight connector. I think you'll find out that if you have a dust collector-not a shop vac- the dust collection is very good. Not perfect but very good. There's no dust around the motor area to speak of.

Did you take out the metal safety plate blocking part of the dust collection port or leave it there (or have a machine from before they were put in). Mine is still there but I'm debating whether to take it out or not.

I had to chuckle when I read your post, converting from 120 volts to 240 volts allows you to reduce the corg gauge, you actually increased. On the plus side you certainly won't have any voltage drop issues.......regards, Rod.

Yeah, that cord was huge! I'm pretty sure the plug that I bought isn't made for cords that big. I actually already took everything back apart and put the original cord back on the machine and just snipped off the plug to replace it. I'm using the original box connectors now, all is well.

[Howard Acheson]

Why did you feel you need a new cable? Any wire sufficient for 120 volts is more than sufficient for 240 volts. It's amperage that determines wire size, not voltage. Your tool will use less amperage at 240 volts than it is using at 120. There you could actually use a smaller wire for 240, not bigger. The only thing you needed is a 240 volt plug for the 240 volt amperage shown on your motor label.

[Steve Schoene]

The other issue not addressed is why you felt the need to rewire to 240 volt. Unless the wire in the wall was undersized to begin with the saw won't behave any differently that it did on 120v. If you were popping fuses, that would be a major sign of reason for change, otherwise?

[Barry Lyndon]

Why did you feel you need a new cable? Any wire sufficient for 120 volts is more than sufficient for 240 volts. It's amperage that determines wire size, not voltage. Your tool will use less amperage at 240 volts than it is using at 120. There you could actually use a smaller wire for 240, not bigger. The only thing you needed is a 240 volt plug for the 240 volt amperage shown on your motor label.

I wanted a new wire because I wanted to keep the original one intact. That way, if I for some reason wanted to go back to 120 I could just put the original cable back on and not have to buy anything more (a new 120v plug because I snipped the original off). As far as the size of the cable...as I said in my original post, I simply asked the guy working in the electrical department if he knew what cable I needed (after telling him what I was doing) and I bought what he gave me. That's all.

[Barry Lyndon]

The other issue not addressed is why you felt the need to rewire to 240 volt. Unless the wire in the wall was undersized to begin with the saw won't behave any differently that it did on 120v. If you were popping fuses, that would be a major sign of reason for change, otherwise?

I actually didn't even have wire in the wall to begin will. I just finished putting a sub panel in the shop and running all new circuits. Since I was already running brand new circuits, and with the advice of others, I decided to go ahead and just drop a couple 240v lines in there as well. The cost was only slightly more because of the 240v breaker so why not. As for rewiring the machine...it was something I hadn't done before and was curious so I tried it out. Super simple process and with no downside that I've seen (with the exception of the small additional cost of the receptacle, plug, and breaker - but if $20 is something to be bothered about then woodworking probably is the wrong hobby for me) and POSSIBLE upsides, why not?

[Don Jarvie]

A few reasons as to the need to rewire..

1st - You can add a long cord depending on the placement of the machine. I rewired my jointer and bandsaw to 240 and added 10 ft cords. Both machines are on casters so depending on what I'm doing I can move the machine around easier.

2nd - If you have limits amps at the panel, mine is 50, with an electric heater (20a) and DC (10 or so) the 7 amp difference (in Barrys case) can help with the amount of amps you are using at one time. 37 is better than 44.

I use dryer type plug and outlet for my TS and planer. The plugs are kind of a pain to pull in and out but cheaper at 10 bucks a shot than 30 for the better plug. Upgrading the plug is on my list of things to do.

[Joseph Tarantino]

i hope you can get that saw wired up again correctly. the 10-325 is a really nice piece of equipment. i have two observations/comments: 1. contact rikon for any info regarding saw rewiring and the gauge of wire needed. they should know more about that saw than anyone and i've never heard of their cust serv. or tech. support getting anything but positive comments. 2. whenever dealing with plumbing or electrical questions @ HD, try to find the dept "pro" they have in the store. in the NYC area, stores all have a pro in electrical and plumbing. any technical questions for anyone else in the store are a waste of time. and even then, there are some HD pros who aren't really field savy pros. moral of the story, you need to know the right answer before going to HD.

good luck with the 10-325. i'd have stuck with 110v. makes automated dust collection activation considerably easier and less expensive. and according to your owners manual, changing voltage doesn't increase the motor's output. if it did, the manual would note a change in HP between 110 and 220. yours is 1.5hp under either voltage.

BTW, did the electrician who wired the new sub panel also install the 220 outlets? how did he know which type to install, or did you buy the amazon linked plug before the 220outlets were installed? just curioius.

[Barry Lyndon]

i hope you can get that saw wired up again correctly. the 10-325 is a really nice piece of equipment. i have two observations/comments: 1. contact rikon for any info regarding saw rewiring and the gauge of wire needed. they should know more about that saw than anyone and i've never heard of their cust serv. or tech. support getting anything but positive comments. 2. whenever dealing with plumbing or electrical questions @ HD, try to find the dept "pro" they have in the store. in the NYC area, stores all have a pro in electrical and plumbing. any technical questions for anyone else in the store are a waste of time. and even then, there are some HD pros who aren't really field savy pros. moral of the story, you need to know the right answer before going to HD.

good luck with the 10-325. i'd have stuck with 110v. makes automated dust collection activation considerably easier and less expensive. and according to your owners manual, changing voltage doesn't increase the motor's output. if it did, the manual would note a change in HP between 110 and 220. yours is 1.5hp under either voltage.

BTW, did the electrician who wired the new sub panel also install the 220 outlets? how did he know which type to install, or did you buy the amazon linked plug before the 220outlets were installed? just curioius.

I did get everything wired back up correctly and safely using the original cable (I have 10ft. of 12-3 laying around now). The sub panel and all the outlets were installed by me with the guidance of my electrician friend. I just bought the 220 receptacles yesterday and wired them up, I also bought the wrong size face plates - oops.

[Chip Lindley]

I use dryer type plug and outlet for my TS and planer. The plugs are kind of a pain to pull in and out but cheaper at 10 bucks a shot than 30 for the better plug. Upgrading the plug is on my list of things to do.

No need to pay BORG prices for 30A 230v plugs or receptacles. I have more TwistLock plugs and receptacles than I will use (both 20A and 30A) bought off eBay. One just has to watch for the bargains to come along. Now, if I was still looking, I would not be giving up prime info! But, since I have more than enough for future needs, it's your turn!

HBL2621-2.jpg

Currently there are a few Auction or Best Offer listings for Hubbell L6-30. Do an eBay search and check 'em out. I have bought quantities as low as $6 each, plus shipping, of course. I love TwistLocks--positive locking of extension cords or overhead drops. L6-30 is the standard 230v plug in my shop. I can run any 230v machine up to 5hp off a 10-3 extension.