So, I'm getting a lift that has 240v, 20amp required. I have wire pulled already in the wall that will support 50amp that is unterminated in a double wide box. Is it kosher to wire a 20amp plug for the lift and a second 30amp plug for a future welder and run both on a 50amp breaker in the panel?
A quick answer is no! Simple reason being one could overheat and cause a fire long before the breaker would trip. Keith
The solution in that case would be to use a sub panel and install a 20 and 30 amp breaker in it. You can buy small boxes that will hold two or 4 breakers. the other option would be to put a junction box at the termination and then Mount two separate fused disconnects to it.
I have BR type breakers. Does that sound correct? Is there any reason I can't surface mount a box like yours at the termination point of my far wall, install a 50A in the main breaker panel, a 20A in the sub panel and connect a box on the side for the 20A 240v circuit with room to add a 30A welder circuit? My house was built by an electrician. In my garage is a single circuit sub panel with a 30A breaker and a metal outlet box directly attached to it for an air compressor. That's what I plan to do for the lift on a slightly larger scale.
It is 4 wires, three conductor and 1 bare copper wire. Here's the box on the far side of the garage. The other is the main breaker box.
My input: You would run a new wire for the 50 Amp circuit to a new sub panel in the garage and wire the circuits to breakers in the sub panel. No need for separate boxes. Hard wire the lift. The welder would be a plugged into a socket wired from a breaker in the sub panel. The gauge of the new wire needs to be sized for the 50 amps and the distance. note - I am NOT an electrician! You have Cutler-Hammer breakers. But - you might could use the existing wire you pulled for 30 Amp service. Do you know the gauge and length? Also, what amp service does the lift need?
The lift requires 20amp. I bought 10ft of 12/3 cable to make a power cord for the lift. The wire in place now is pretty big. Same size as my 50amp AC. Maybe 10ga? For now, I'm going to put a 20a breaker and twist lock receptacle on the wall. I'll update to a sub panel when I get around to learning to weld.
Yes, there is a reason: the wire size. You need to size the wire for the load and the length. If the wire was sized for 30 amp then you can't simply change the breaker to a 50 amp. The size is printed on the side of the wire. What does it say?
Should be good. Figure out the size of the wire and post it for reference. http://www.paigewire.com/pumpWireCalc.aspx?AspxAutoDetectCookieSupport=1
Simply put breaker & wire size must match 12 awg for 20 amp 10 awg for 30 amp 8 awg for 40 amp 6 awg for 60 amp If your in between on amperage the use the next larger size wire such as a 50 amp breaker you’ll need the 6 awg Imstalling a small sub panel for 2 connections is the expensive way to go. Just run two separate breakers and wires and plugs, 1 20 amp for you lift and 1 separately for your welder, the lift you only need a normal 20 a, house plug, the welder you will use the same one that’s for any 240a. Dryer in your house.
I think you're making it too complicated. If your 3 conductor plus ground is already in place is at least 10 AWG (or 8 or 6 AWG, which are larger), why not just install a 30A 2 pole breaker in your main box where the other end of the wire goes to? In the garage wall box, install a 30A female outlet. Then, put a matching 30A plug end on the power wire for the lift (making it larger than you need is OK, just not smaller), and the same 30A plug on your welder. When you want to weld, pull the lift plug out, and plug in the welder. In theory, there might be a small risk in that your lift power cord is probably only 12 AWG, but since it is a cord to an "appliance", it is sized for the appliance/motor load, and that situation is in code compliance. We plug light gauge wired lamps and other household items into 15 and 20 amp rated outlets all the time. Those household items are usually wired with pretty light gauge wire. Full disclosure, I am not a licensed electrician, but have done electrical design and overseen fabrication for industrial control and 3 phase power circuits in my past working life. House wiring in single phase is pretty straightforward, and the code is not difficult to adhere to. Most of the time, code compliance issues are due to ignorance of specific code items. An example in this case is that the code MIGHT require some sort of "disconnect" device adjacent to the lift, although I believe the code considers the plug to be a "disconnect device". The lift motor itself is very likely to be overload protected internally with thermocouples, so motor protection protocol upstream of the motor would not be required. Others may be able to confirm what I am suggesting is OK. I haven't looked at a code book in several years.
You’re pretty much right to a point, but the factory 20 amp plug on the lift isn’t rated for 30 amp so when you cut it off to be able to plug into the 30 amp receptacle that matches the welder plug, you have altered the factory plug and now it’s a violation.
The wire is probably 60ft by the time it runs up the wall and down the other side, completely across the ceiling of the garage. I don't find any writing on the wire but it will fit in the 20A 240V breaker I bought today. There is currently NO breaker in the box. The wire was run at my request in 2007 when I built the garage. The electrician said it would run whatever I wanted to hang off it. I want twist lock for these so nobody gets the idea they are just "funny" plugs. Also, my storage shed (for all the stuff that I don't want in the garage) is on the other side of this wall. I have visions of dropping a 20A 120v circuit underground to it for a light and an outlet to keep the mower battery charged. Complicated, maybe. I'm going to let the installer hook up the lift. I might change things around later but I don't want to do anything to the actual wiring of the lift itself. Yeah, I don't want to do anything that will be a red flag if I need to sell the place or downsize much later in life. I want to do it right and I have the ability but not the knowledge. For now, 20A in the main panel, use existing wiring, 20A 240v receptacle in wall with twist lock and 12/3 with matching twist lock plug for lift pump.
That’s all sounds fine, and anything under 300 ft long run and there’s little voltage drop to contend with.
There are definitely NO markings on the wires whatsoever. The wire is actually larger than the wire feeding my 50A AC breaker but smaller than the 100A service wire. What is the measurement for gauge of wire?
