OpenEVSE Board Error

[Izhar]

Hi All:

I have been putting together my Open EVSE board for the last month or so.  When I completed it, with the RGB LED Display attached the board goes from white (booting), the clicking sound comes from the relays, and then the board displays red (error).  I checked the output voltage, and find that 120v is still coming out while the board is in error.  Since the input voltage is 240, i figured one of the relays was still open.  When I attached a volt meter to  the output of each really, one was open and the other was closed.

Has anyone come across this problem before?  The next thing I was going to check was to see if the Open EVSE board to see if 12v was still being fed to the relay even though the board in in an error state or if the relay is broken and is on all the time.  Any advice anyone can give me would be greatly appreciated.

Izhar

[Craig Kirkpatrick]

The three-terminal connection to actuate the relay should have 12V on the center screw all of the time and the side screws "turn-on" by switching to a path to ground thru transistors.

Possible error states leading to the red led:
#define EVSE_STATE_DIODE_CHK_FAILED 0x05 // diode check failed
#define EVSE_STATE_GFCI_FAULT 0x06 // GFCI fault
#define EVSE_STATE_NO_GROUND 0x07 //bad ground
#define EVSE_STATE_STUCK_RELAY 0x08 //stuck relay
#define EVSE_STATE_GFI_TEST_FAILED 0x09 // GFI self-test failure
#define EVSE_STATE_OVER_TEMPERATURE 0x0A // over temperature error shutdown

With the car not connected you should never see the Diode or GFCI fault. Be sure your ground is connected from the AC mains side of things or you could see the Ground error. Post a picture of your wiring and I'll be able to spot if you mis-wired the relay actuation that could lead to Stuck Relay. If you do not have the GFI CT built correctly and wired correctly to its 3-pin header then you will see the Gfi Test failure. I don't think you have the firmware with the very new Temperature monitoring.

This should give you a lot to investigate. Let us know if we can offer more help and advice.
-Craig

[Izhar]

Hi Craig:

Thank you so much for responding to my questions.  Things have gotten a bit busy at work, so I haven't had a chance to take a look at the items you mentioned.  I'll measure the resistance to the GFCI, double-check all the grounds, and then see if I can determine if the relay is stuck.

Izhar

[Craig Kirkpatrick]

Izhar, very good. Give us more symptoms you witness and maybe some pictures of the wiring. And with your own investigation of the circuit we will have you running smoothly very soon.
Good luck and best wishes,
Craig

[Izhar]

Craig,

So I went through all the possible errors as follows:

DIODE_CHK_FAILED - Not yet connected to car, so eliminated this possibility

GFCI_FAULT - Not yet connected to car, so eliminated this possibility

NO_GROUND - Checked all the ground connections and checked to make sure ground is connected to the AC Mains, all the grounds showed  good connection to the AC main ground.

GFI_TEST FAILED - Used an ohm meter to check that the GFC CT was built correctly.  Orange to Black measured 0 ohms, White to black measured 45 ohms.  Everything looks good with this.

OVER_TEMPURATURE - Not implemented and I don't believe I have the firmware for this.

This leaves me with the strongest possibility that I am dealing with a stuck relay.  I check the voltage on the Open EVSE board and does show the relays being activated during the initialization test.  One of the relays remains connected after initialization is completed leaving that line with AC power flowing, it was measured at 120V (which is half the 240 flowing in), the other relay does not stay connected.  I would assume that after initialization is completed both the relays should not stay connected until the correct pilot signal is received.

I guess the next question would be, is it the really or is it the connection?  I doubled check the wiring and it looks correct.  See pictures below.

Let me know want you think.  If you feel the connection looks good from the pictures, then what I will do is relay the relay that keeps the connection open and see if that solves the problem,

Thank you for all your help,

Izhar

[Craig Kirkpatrick]

Izhar, I studied the wiring and it looks normal.  Yes it seems you have a stuck relay. A stuck relay when you just finished building the kit seems very odd.  

The EVSE design is such that normally the relays open and close with no current flowing in order to avoid wearing out the relays.  It is part of the nicely designed J1772 protocol  between the evse and the car.  So even after years of charging a car the relays should still be fine.  It seems you just have a bad relay.

Luckily the replacement relays are pretty inexpensive.  http://store.openevse.com/collections/accessories/products/30a-spst-relay

Maybe if Chris reads this he'll just send you a replacement since it seems like you got a relay that was dead-on-arrival.

Best Wishes,

Craig

[Izhar]

Chris:

That was my conclusion as well after I doubled-checked everything.  I contacted Chris and he was nice enough to send me a replacement relay.

I appreciated the help and guidance that you provided me.  Your guidance helped me narrow down the possible causes of the error message and isolate the specific cause.  Once the replacement arrives hopefully everything will be good to go.

Thank You,

Izhar

[Izhar]

Ok, Chris sent me replacement relays and I installed them this weekend.  The following was the result of replacing the relays:

- Using a 120v line everything was fine.  The circuit went through initialization and the LED light went from white to green.  I attached the EVSE simulator and was able to test each state successfully.  I attached the unit to the car and charger commenced without any issues.

- Using a 220v line the unit went from white to red.  I had just completed soldering the monochrome LCD display and plugged in the unit and I got a "stuck relay" message. turned off everything and attached the J1772 plug to my Leaf and then plugged the unit into a 220 line and the unit started charging the car at about three times the speed of the 120 line.

Has anyone come across this situation where the 12v relays work fine at 120 but get stuck at with 220 voltage?  I am using the Open EVSE Plus 2.5 board.

Izhar 

[Craig Kirkpatrick]

It sounds like the AC Test wires are not connected correctly. You have heavy gauge wires from the fuse block to each relay. From the fuse block you provide AC power to the V2.5 board over small gauge wires. The AC test small gauge wires need to reach the J1772-cable side of the relays and the wires need to match the input side - meaning don't cross the AC test wires. During the relay test at powerup one relay is closed at a time and the output state of the relay is checked. If the car is connected prior to connecting the AC mains to the EVSE then the relay test is skipped and that explains why your car charged ok.

Double check the wiring of the AC Test wires. Here is a diagram.
https://d17kynu4zpq5hy.cloudfront.net/igi/openevse/ZXtgCukabtnfFN2S

[Izhar]

Hi Chris:

Thank you for the assistance.  I will check the wiring when I get home from work and see if the AC Test wires are crossed.

Izhar