Home Charging

I think you will get a better answer by posting your question on the Plug-in forum: Toyota Prius Plug-in | PriusChat

 

240 is simply 2 120 circuits run from a double breaker to a 240v outlet. nothing could be simpler and easier except a 110v circuit which the pip will charge from.

 

240 is two 120v circuits from the breaker box BUT they are out of phase with each other so that when one is -120vac the other is +120vac. Measure across both and you get 240vac. Biggest advantage? You get twice the power (watts) from two "hots" than from one. So if you need 15000 watts for a central heater element or an electric oven, you can use smaller gauge wires on a 240 vac circuit. To get the same wattage from a single 120v circuit would take twice the diameter (gauge) wires. So technically you could use a 120 to 240 transformer to give you 240 volts. But the wire gauge has to be much larger, plus the transformer would waste some of the power in heat and magnetic flux loss. Bottom line, it makes sense to run a proper 240 v circuit, 2 hots, 1 neutral and a ground when called for by the load. Plus the wire can cost less than a properly sized 15000 watt transformer.

 

Since this is in the Prius v forum and there is no plug in v I put "Something Else".

 

Yup, no PHV-V yet.

 

Had there been a Prius v PHV, I would have purchased one. But I need the space, so I get a 'normal' v. Cetainly none of the other cars mentioned would have had the cargo capacity of even the Prius PHV.

 

FWIW- the EVSE (charging cordset) included with the PIP (Plug-in Prius) from the factory only charges off 120v AC power.

The PIP's charging port can accept either 120v or 240v power. Commercial charge stations have their own 240v cable/connector that connects directly to the PIP's charge port without using the factory EVSE.

It takes about 3hrs to full recharge from empty on 120v or 1.5hrs to charge at 240v.

It you want to charge at 240v at home, you can install a commercial 240v charge station and that will plug directly into the PIP's charge port.

Or you can run your own 240v outlet using common 12/2 wire and send the PIP's OEM EVSE out for modification so it can charge using 240v (and still use 120v w/adapter cable) at twice the rate of the 120v recharge.

 

It's not difficult to install a 240 outlet in the home. There are many YouTube videos which explain this in good detail. It is a standard procedure which is safe and easy to do, and many home owners do it themselves. The most expensive part may be the permit. Of course, you can just hire any licensed electrician and they'll do this work. It's just a plan old outlet, as if they're installing an electric clothes dryer, electric oven, or an air conditioning unit. *Any* electrician can install this for you.

You will need to run this outlet directly to its own circuit in your circuit breaker panel. It needs to be ground fault protected. I bought a 240V 20A ground fault protected breaker for around $40 online. My home has two circuit breaker panels: One inside the house, and a panel outside, where the electricity enters our home. It was much easier for me to run the cable from this outside panel to my new outlet. First you run the Romex cable from the circuit breaker box to the new outlet location. That's about 90% of the work. Your local electrical code will specify the type of cable you should use, how many inches apart the staples must be, and the type of conduit, if any, it must be run through. In my case, I was able to run it through the crawl space beneath my house, stapling it every 18". When I reached the location where I wanted the new outlet, I drilled a big hole, and ran the Romex cable through a short nipple to the new outlet box. The outlet will depend upon the amperage you're using, but you want to be sure it mates with the type of connector on your 240V charger.

You attach one end of the Romex cable to the new outlet, then you attach the other end to the circuit breaker, put the breaker in the breaker box, and switch it on. After you watch a few YouTube videos, you'll understand exactly how to do this. If you want to be absolutely safe, kill power to your house by switching off the breakers which feed the panel. I didn't do this.

It's like this: One one end of the circuit breaker, you attach the wires from the Romex cable you just ran. These, obviously, aren't energized. On the other side, you attach a small "pig tail" cable from the breaker to the "bus bar" (ground) in your panel. You also attach a separate ground wire from the Romex cable to the bus bar. So far, you haven't gotten close to any actual power yet, just a grounding bar. The circuit breaker, which is now in your hand with some de-energized wires attached, should be in the OFF position. You then snap it into the breaker panel, and THEN you turn the new breaker on. Your new outlet is now working. Go plug something in and check it out.

I can give you more details if you're interested in this do-it-yourself project.

 

I don't think this is exactly right. Commercial power is generated as 3-phase power. Thus each side is 120 degrees out of phase with each other. In a residential setting any one home gets just 2 of the 3 phases...so they are not 180 degrees out of phase with each other. Otherwise, what you say is generally correct.

Mike

 

If two 120v supplies aren't 180 degrees out of phase they won't add up to 240v. Your house uses a center-tapped output of one phase of the 3-phase power line. Center tap to ground, each hot wire is 120v of 180 degree opposite phase. This is accomplished with the large transformer on the power pole you see every few houses down the street if you don't have underground power lines.

Would you believe my Electrical Power mid-term exam was graded on English grammar as well as technical matters by the visiting German professor?

Further... did you know that the motors in the Prius are 3-phase AC?

 

I use an electrical oven in my house. It combines two wires on the circuit breaker to make 240V. Can I use an 240V power strip (splitter) at the outlet of the oven to make two 240V outlets? One goes to the oven, and the other goes to 240V charger for my PIP using an extension cable. I understand that I may not be able to use both at the same time. Does this design work? Is it safe providing I use quality cables with good gauge.

 

never heard or seen anything like that. i think a dedicated breaker would be best, but it would probably work most of the time. do not know if it would meet code.

 

Please do not do anything like this. It's not safe and it's against code. And I don't know of any 240V power strips/splitters available for home use like this, probably because it's against code. And if a fire results from this, your homeowner's insurance could deny a claim against the resulting damages.

 

Yet this is the standard configuration in most of the world, which uses 240V/50Hz for residential power. The standard household plug in Great Britain looks almost like our clothes drier plug. They also have a lighter-duty "razor" plug but that is used only for specific purposes. So why are 240V outlets dangerous in the U.S., but is the accepted practice elsewhere? And we are not talking about developing countries here, who might cut a few safety corners.

 

If I had to make a guess it's because the only things we use 240V for are high-draw appliances like electric water heaters, electric ovens or stoves, electric clothes-dryers, whole-house A/C units, EVSEs, welding equipment, etc.

 

It is against code, for residential use. However, they do make all sorts of 240v cords and connectors...commonly seen in big convention centers during trade shows, etc.

Mike

 

Yeah, we use a variety of 208V/220V240V PDUs (Power Distribution Units) at work, but I would never try to use one of them at home.

 

But there are 2 more smaller guage wires, where do those go? On the house side.

 

There should be a possibility of changing the power plug yourself, w/o professional help so you could use 220 or 110V it's just simple wiring.