Automatic Dryer Plug Switcher?

[pchilds]

You could replace the relay in your EVSE with a dpdt relay, feed the dryer with the NC contacts. When the EV is charging the dryer will be off.

 

[johnrhansen]

Putting the power lines on a DPDT relay (would be a great application for the relay the Juicebox comes with) would work okay, and I like the countdown timer idea. The problem I foresee is maybe someone who's not so EV-savvy (wife?) comes along and decides to switch over to the dryer while you're in the middle of a charge. Then you get a hard shutdown of the power to the EVSE and error codes in your EV or possibly even real damage to your charger (although I'm sure that's very unlikely.) Plus I could imagine the wife complaining about the dryer not working because she forgot about setting the timer, or it's a time when it wasn't preset for the dryer to be on, etc.

While switching the power lines is the "pure" solution of guaranteeing that only one appliance is powered at a time, I'm sure using any such device would never pass an inspection anyway. Cutting the pilot when the dryer pulls current is really just as good of a guarantee that charging and drying won't happen simultaneously, and it gracefully stops charging that might already be happening. Plus you don't need a large relay and you don't have to set any timers or throw any switches manually.

There is no fail safe there.if the circuit quits working, its possible both could be on at the same time. I like the idea of the dpdt relay in the evse. If you haven't already procured one you could build the entire thing into the evse. A dryer cord in, and a j1772 and a dryer receptacle out! If the evse is not charging, then the dryer works. The dryer doesnt care if you cut the current off. Its load is mostly resistive.

 

[johnrhansen]

Putting the power lines on a DPDT relay (would be a great application for the relay the Juicebox comes with) would work okay, and I like the countdown timer idea. The problem I foresee is maybe someone who's not so EV-savvy (wife?) comes along and decides to switch over to the dryer while you're in the middle of a charge. Then you get a hard shutdown of the power to the EVSE and error codes in your EV or possibly even real damage to your charger (although I'm sure that's very unlikely.) Plus I could imagine the wife complaining about the dryer not working because she forgot about setting the timer, or it's a time when it wasn't preset for the dryer to be on, etc.

While switching the power lines is the "pure" solution of guaranteeing that only one appliance is powered at a time, I'm sure using any such device would never pass an inspection anyway. Cutting the pilot when the dryer pulls current is really just as good of a guarantee that charging and drying won't happen simultaneously, and it gracefully stops charging that might already be happening. Plus you don't need a large relay and you don't have to set any timers or throw any switches manually.

There is no fail safe there.if the circuit quits working, its possible both could be on at the same time. I like the idea of the dpdt relay in the evse. If you haven't already procured one you could build the entire thing into the evse. A dryer cord in, and a j1772 and a dryer receptacle out! If the evse is not charging, then the dryer works. The dryer doesnt care if you cut the current off. Its load is mostly resistive.

 

[fooljoe]

There is no fail safe there.

Yeah there is, it's called a breaker! You could add another 30 amp breaker at the device for additional peace of mind if you're worried about the current-sensing relay failing closed.

 

[LeftieBiker]

The simplest, most foolproof solution might be similar to the panel interlock we have for the backup generator. A sliding bar prevents both the generator feed breaker and the main feed breaker from both being on at the same time. Something similar could be used with a manual either/or EVSE/dryer switch.

 

[GlennD]

you cannot have the dryer and the evse on the circuit at the same time. It creates the possibility of overloading the circuit. What I would do is use a Double pole, double throw relay in a box that switches the line to either the evse or the dryer. Connect the control coil to a cord connected to a 5-15 plug on the other end. Plug that end into a programmable wall timer. Figure out the times you want either to work and set the timer.

If he uses the dryer to switch the EVSE he does not have any possibility of overloading the circuit since only one device can be active at any time.

 

[GlennD]

Here are some relay links.

http://www.aliexpress.com/item/JQX-62F-" onclick="window.open(this.href);return false; ... 83981.html\

http://www.ebay.com/itm/New-40-amp-2-pole-240-v-coil-Definite-Purpose-Contactor/221440908683?_trksid=p2050601.c100085.m2372&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20140211132617%26meid%3D8252180048754029307%26pid%3D100085%26prg%3D20140211132617%26rk%3D1%26rkt%3D4%26sd%3D221440908683%26clkid%3D8252180887575439653&_qi=RTM1562569" onclick="window.open(this.href);return false;

 

[kevinleaf]

GlennD the first relay link got messed up. Can you paste it again please? You might need to use http://bit.ly" onclick="window.open(this.href);return false; or another shortener so that the message board doesn't scramble it.

I am probably going to try the pilot line interruption method first but in case that doesn't work I'll try the other. I know that cutting power to the car during charging could raise an error but I have Leaf Spy Pro to clear it out ;-) I do want to do this as close to the right way as possible though, and interrupting the pilot line sounds fairly clean.

Thanks!

 

[GlennD]

Yes, the link is now bad. It was a link devin on the RAV4 EV posted. I purchased 4 relays for $11.78 through the link. It was cheap while it lasted. You can buy the relay from the JuiceBox people for $15.

 

[pchilds]

The aliexpress link got corrupted somehow.

http://www.aliexpress.com/item/JQX-...il-Electromagnetic-Power-Relay/468483981.html

 

[Devin]

Here's my conundrum...



This is at my grandparent's house and I'd like to make 240V charging available there, particularly since the wiring is pretty much in place. The outlet in the workshop is on a common wall with the garage, so would be trivial to make it available there.

I want to swap the 10-30 outlet to a 14-30 (with new 4-wire feed). Then I want to replace this switch (which allows both loads to be connected simultaneously in it's current configuration ) with some sort of DPDT arrangement. I've looked at simple wall toggles but haven't found anything capable of 240V/30A that is affordable, so I think I'm going to use another one of those JQX DPDT relays like I used in the OpenEVSE and connect it to a wall/light switch of some sort. I want it to default to the dryer since I will be the only one using the outlet in the garage. What would people recommend as a simple and safe way to drive the relay itself?

 

[kevinleaf]

You can drive the relay with a light switch switching one leg of the 110v. I believe the contacts on those relays are 110v AC or DC but double-check it. There is so so little current drawn by the relay it is safe, but perhaps not 100% up to code.

 

[pchilds]

The wire on the top looks like aluminum. Make sure you use AL rated connectors when hooking up your relay.

 

[ElectricEddy]

The simplest, most foolproof solution might be similar to the panel interlock we have for the backup generator. A sliding bar prevents both the generator feed breaker and the main feed breaker from both being on at the same time. Something similar could be used with a manual either/or EVSE/dryer switch.

Agreed. Works way better than doubled up lugs on a fused disconnect.

 

[pilotnbr1]

Any updates? I have one 220v outlet with a dryer on it and no spare space on my breaker box to run another 220v circuit... I like the automatic switching idea that defaults to the evse as the primary and dryer as secondary.

 

[johnrhansen]

Yeah, manual is easiest and cheapest. But if you insist on automatic you could also set it up with a DPDT relay. Energized enables the dryer, and de energized enables the EVSE. You run 120 volts to the coil through a 12 hour intermatic dial type timer. This way your system doubles as a charge timer. Say you come in at 3, set the timer for 7 hours, plug your car in. Do laundry to your hearts content. at 10 pm, your dryer goes off and your car starts charging.

 

[smkettner]

Any updates? I have one 220v outlet with a dryer on it and no spare space on my breaker box to run another 220v circuit... I like the automatic switching idea that defaults to the evse as the primary and dryer as secondary.

Your box is full of double breakers? Have a pic?
Otherwise I was looking at parts to build an automatic switch and it would have been close to $400, so a sub-panel would probably be easier.

 

[fooljoe]

If your EVSE uses a DPDT relay, like for example the one in the Juicebox, in addition to the NO contacts that your J1772 cord connects to it'll have NC contacts that are energized whenever you're not charging. Simply wire those contacts to a dryer receptacle and plug your dryer into that, then plug your EVSE into the existing dryer outlet and you're set. Of course you'd have to put a new hole in your EVSE enclosure (or just move the parts to a different enclosure), but if you wanna make an omelette...

 

[DaveinOlyWA]

I typically only dry clothes once a week. You need the dryer every night? :shock:

+1 I did that at my old house and used the dryer "maybe" 1-2 times a week. If not for the kid, it would be less than that. We basically have 4 laundry baskets.

sensitive
whites, towels and other "durables"
permanent press and other "wrinkleables"
the Kid (his clothes were generally a different level of dirty mixing his with ours was not something we wanted to experiment with)

Now, because I was main LEAF driver, I did nearly all the laundry (there was some clothes I was not allowed to wash and it all stems from the "Red Shirt" incident 8 years ago...)

But generally laundry day was only once a week and yes, we washed a good 4-7 loads or so. more in Summer, less in Winter

 

[kevinleaf]

OK, so I got the switcher working but didn't put it up right away because I was afraid of the backlash. Although I feel this is a totally safe way of doing this perhaps I missed a bit of electrical code somewhere. You can still fell free to tell me if I did something not safe here.

I used the relay from the JuiceBox. It is 80A 2-pole with a 12v DC coil.
http://www.emotorwerks.com/products/online-store/product/show/132-replacement-relay-for-juicebox

The relay either sends the two phases to the dryer or the EVSE but never both at the same time. So far my car has not complained about the power being yanked from it while it was charging.

For relay coil power I used an old Colecovision power supply from the 80s for a bit of nostalga. Because it is switching low voltage i just used a simple single pole toggle switch. Also I have plugged the power supply into an X-10 module so I can switch it on/off from my bed and eventually on a cheap X-10 timer. This allows me to let the dryer start at 11p and finish at 12a when I am paying off-peak rates.

So materials: 2 NEMA 10-30R outlets: $6.50 each and $15 for the relay. Everything else was scrap from previous projects. Under $30 total and 2 hours of work.

Future enhancements: indicator to show me if the switch is in the car charging or dryer position. A simple LED would do the trick. Even better would be integration into a home automation setup that warns me at a given time on my smart phone if the car is not set to charge, or even better switches by itself. Automatic switching to EVSE if the dryer is not in use would be nice. I'd like to do a neater job of the wiring too but not totally necessary.