Portable OpenEVSE at 40A

[GlennD]

Here is the 12V coil version.

http://www.amazon.com/gp/product/B008MU0IU2/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1

 

[pchilds]

Why pay more with Amazon? $11.63 for 1, $22.08 for 2.

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

 

[ehelmholtz]

Why pay more with Amazon? $11.63 for 1, $22.08 for 2.

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

Good find, Phil. and I thought my eBay $15 was a good deal :-|

 

[GlennD]

It is interesting that you can use a 28V relay. The Qianji specs are pull in at 90% and drop out at 10%. That is far below the JuiceBox's 15V or the OpenEVSE's 12V. It would be nice since it would draw half the current.

The catalog pages are available for download via a Google search but the link is very very slow.

 

[nsayer]

I used these for the Mega Hydra: http://www.grainger.com/product/DAYTON-Compact-Contactor-6GNV0

They're more expensive, and they require a contactor adapter, but they're UL and CE approved, which I think has definite value. Besides, if you're willing to spend $400 for J1772 cables (that's a pair remember), the extra $30 for good contactors can't be too onerous.

They're rated for a 40A inductive load, but with a resistive load (I think an EV would qualify) they're rated for 50A. The Mega Hydra is 25/50 rated (though since mine has a NEMA 6-50 on it, that reduces it to 20/40).

 

[GlennD]

Using a 240V contactor defeats the use as a L1 device.

I realize your Hydra is a 240V only device but I am trying to build universal devices.

Realize UL parts are likely quite safe to use but no modified commercial device or home made device is UL approved. Budget Chinese parts safe or not will never be submitted for approval since it costs real money. As I understand just changing the input cord of an EVSE is enough to invalidate the approval and it would have to be resubmitted with new fees for approval.

 

[nsayer]

Using a 240V contactor defeats the use as a L1 device.

Well, sure, but unless you find a TT-30 (and your car supports high current L1), L1 only happens at 16A. And a universal device will never go higher than 40A because there aren't outlets that go higher than 50A (and they need the 20% derate).

I realize your Hydra is a 240V only device but I am trying to build universal devices.

Realize UL parts are likely quite safe to use but no modified commercial device or home made device is UL approved. Budget Chinese parts safe or not will never be submitted for approval since it costs real money. As I understand just changing the input cord of an EVSE is enough to invalidate the approval and it would have to be resubmitted with new fees for approval.

I can take responsibility for my own assembly skills, but I count on UL/CE registration for the parts I use (where applicable), because I have no way to determine whether those parts individually are safe for use at their rated capacity or not - particularly when they come from random Chinese eBay sellers.

I have had EVSEs I've built smoke more than once. It's never been because of a UL approved part. Anecdotes are not evidence, of course, but I personally feel a lot better not buying Wun Hung Lo relays.

 

[GlennD]

Well the Qianji relay claims CE on the cover. No one uses the dust cover in an enclosure since it restricts how the terminals exit. I do not agree with it's 80A rating but it works fine at half current. With good ventilation it could work at 80A but a device that runs hot bothers me.

The JuiceBox people now list the relay at their store for $15.

 

[miimura]

AutomationDirect.com also has in interesting line of open frame 40A relays. I don't know enough about the details to know if its really comparable to the others discussed here though. I just thought of looking there because Grainger is usually overpriced. They also have large contactors that are designed as three phase motor starters, but it's totally overkill for an EVSE.

Another question: is a Contactor inherently a Current Interrupting device? I'm sure there are many relays that can do a good job if they only actuate when the current flowing through is very low or zero, but part of the job of the EVSE is to interrupt the current in the case of an error condition. Is it always possible to signal the car to abort charging in time so that there is no arcing in the relay?

 

[nsayer]

Another question: is a Contactor inherently a Current Interrupting device? I'm sure there are many relays that can do a good job if they only actuate when the current flowing through is very low or zero, but part of the job of the EVSE is to interrupt the current in the case of an error condition. Is it always possible to signal the car to abort charging in time so that there is no arcing in the relay?

So far as I know, a contactor is just a fancy word for a relay that generally has a line-powered coil rather than one powered by DC.

I did a quick google and also found that people call them contactors when they're simply rated for very high power.

A relay is always supposed to be able to break a current flow at or below its rating, so a relay is inherently a current interruptor too.

The entire purpose of the J1772 spec is to insure that the relays/contactors are only ever opened or closed under zero load. The only exception is a GFI fault, which is supposed to break the circuit immediately.

 

[pchilds]

Difference between Contactor and Relay
• Since a contactor is required for a higher load, a relay is always cheaper than a contactor.
• A relay is normally used in appliances below 5KW, while a contactor is preferred when the appliance is heavier.
• A relay is used only in control circuit while a contactor can be used in both control and power circuits.
• In general contactors are little slower than relays
• Contactor is so designed that it can be repaired while it is not normally done in the case of relays.


Read more: http://www.differencebetween.com/difference-between-contactor-and-vs-relay/#ixzz33dgZ6Tnx

 

[DevinL]

Hey everyone,
It's finals week for me so I haven't had a chance to update my parts list yet, but I just wanted to thank you guys for all the help so far! This is my post-finals project so I'll be diving into it properly next week.

 

[pchilds]

Dual EVSE for sale on ebay. I am not the seller and know nothing about the seller.
http://www.ebay.com/itm/Dual-EV-Ele...door-Out-/171332101499?_trksid=p2054897.l4275

 

[nsayer]

Dual EVSE for sale on ebay. I am not the seller and know nothing about the seller.
http://www.ebay.com/itm/Dual-EV-Ele...door-Out-/171332101499?_trksid=p2054897.l4275

My spidey-sense is tingling.

 

[fromport]

It is interesting that you can use a 28V relay.

I think the relay is specified at 12 volt.

The relay can switch 80 amps at either 250Volt AC _or_ 28Volt DC

With DC you get a spark where as with AC the flow stops xx times per second anyway.
Hence the difference in voltage it can switch.

That is how i understand it.

 

[DevinL]

Okay, finals are over so I'm back to building my OpenEVSE. It's now my highest priority project since we have the BC2BC rally coming up in August and before that we are planning to make a trip to Milford, UT and would need the OpenEVSE to do it in the RAV.

Here's my updated parts list. After considering everyone's advice and some further thought I don't think I need a breaker given that no vehicle capable of drawing more than 40A will ever be connected to this unit. If you guys could give another quick perusal of my parts list that'd be awesome! Thanks again!!!

---New/Changed---

OpenEVSE Plus v2 (Quick Kit)
OpenEVSE $115.00 x1
http://openevse-store.myshopify.com/products/openevse-plus-v2

JQX-62F 2Z 80A DPDT DC 12V Coil Electromagnetic Power Relay
AliExpress $11.63 x1
http://www.aliexpress.com/item/JQX-62F-2Z-80A-DPDT-DC-12V-Coil-Electromagnetic-Power-Relay/468483981.html

CR Magnetic CR8420-1000-G Current Transformer
Amazon $11.73 x1
http://www.amazon.com/CR-Magnetics-CR8420-1000-G-Current-Transformer/dp/B005CWO4X0/ref=pd_sim_sbs_indust_1?ie=UTF8&refRID=0F4YSC86TECWTK8JMBD1

OpenEVSE RGB LCD
OpenEVSE $35.00 x1
http://openevse-store.myshopify.com/products/openevse-rgb-lcd

---Unchanged---

GE WX9X35 4-wire Range Cord (4ft)
Amazon $15.91 x1
http://www.amazon.com/General-Electric-WX9X35-4-wire-4-foot/dp/B004LYLP7I/ref=sr_1_3?ie=UTF8&qid=1401408779&sr=8-3&keywords=50+amp+range+cord

J1772 Plug/Cable Assy - 40A (15ft)
QC Power $130.00 x1
http://shop.quickchargepower.com/product.sc?productId=8&categoryId=1

Aluminum Grounding Bar
Home Depot $4.77 x1
http://www.homedepot.com/p/Blackburn-Aluminum-Ground-Bar-Only-IBT3AB-B1-10/202786635#.UYEzaaKyD8I

Metal Pushbutton LED Ring
Adafruit $4.95 x1
http://www.adafruit.com/products/481

5.9" L x 5.9" W x 3.5" H NBF-32010 Box
DigiKey $11.60 x1
http://www.digikey.com/product-detail/en/NBF-32010/377-1765-ND/2328537

 

[GlennD]

If you can solder the DIY kit is $89 vs $115 for the surface mount DIY.

I went from a 20 ft cable to a 25 ft cable. I no longer have to back in. The price is minimal to go to 25 feet. A 25ft cable is $204 with their expensive Fedex shipping.

 

[nsayer]

If you can solder the DIY kit is $89 vs $115 for the surface mount DIY.

But that board doesn't fit in Chris' fancy enclosure.

Oh wait. Neither does the contactor. Never mind.

 

[GlennD]

There is more than enough room but you have to drill new mounting holes in the thick lexan plastic mounting plate. I think if you did not care about weatherproofness and mounted to the bottom directly a small contactor would even fit. I know I was able to mount a Barbouri Ver 4.21 board and power supply.


The biggest problem is the height.

 

[nsayer]

Yeah. I built a Hydra with two "compact" 50A contactors, but I built it in Polycase's largest WC series box...