DIY Electric Car Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
1,364 Posts
Discussion Starter #1 (Edited)
Further to the work undertaken on the Rear High Voltage Junction Box ("HVJB") by Jeff and Kenny, I've taken a look inside the Front HVJB :cool:

The Front HVJB has the following connectors;

"Brown" - HV to PTC Cabin Heater
"Orange" - HV to A/C Compressor
"Blue" - HV to DCDC
"Grey" - HV to Battery Fluid Heater
"Black" - LV signals

The HVJB also has a heavy duty earth strap and two holes for the HV input cables.
 

Attachments

·
Registered
Joined
·
1,364 Posts
Discussion Starter #3 (Edited)
A quick look at the PCB reveals four HV fuses and a busy power circuit.

Fuse F1 (20A) connects the HV to the "Grey" connector via three IPB60R099CPA MOSFETs (here) and a .005R WSL2726 resistor (here). I suspect the busy power circuit is controlling the MOSFETs and has no connection with the other fused supplies.

Fuse F2 (40A) connects the HV to the "Orange" connector.

Fuse F3 (40A) connects the HV to the "Brown" connector.

Fuse F4 (20A) connects the HV to the "Blue" connector.

All HV connectors have HVIL pins that are connected to the PCB. The case lid and HV input cables also have detection switches.
 

Attachments

·
Registered
Joined
·
933 Posts
There is current measurement after the fets, see the curled up busbar.

Wait a minute, why would the fets control the HV to the 'grey' HV connector and measure current?

So would this mean that the PTC heater (water???) be a dumb module? Ah 2013 module looking at some info the battery heater just needs a pwm into the junction box.

Plus nice isolation devices (Big SMD packages) just like on the bms slaves.
 

·
Registered
Joined
·
1,364 Posts
Discussion Starter #5
So would this mean that the PTC heater (water???) be a dumb module? Ah 2013 module looking at some info the battery heater just needs a pwm into the junction box.
Yep... here's the key info :D
 

Attachments

·
Registered
Joined
·
141 Posts
There is current measurement after the fets, see the curled up busbar.

Wait a minute, why would the fets control the HV to the 'grey' HV connector and measure current?

So would this mean that the PTC heater (water???) be a dumb module? Ah 2013 module looking at some info the battery heater just needs a pwm into the junction box.

Plus nice isolation devices (Big SMD packages) just like on the bms slaves.
I have parts from a 2015 70D...

1) the PTC Cabin Heater operates from CAN. Like some of the other Tesla modules, it has a Tesla designed control board that drives a main board. I did see some recent hacking by others on controlling the mainboard IGBTs directly. The heater is fairly large and I'm 50/50 I can get it to fit into my airbox. I'm hoping Damien gets a look at it.

2) the Air Conditioning Compressor was also CAN controlled. I also bought a 2014 Tesla compressor which is reportedly PWM controlled, but I haven't done any experimenting with it yet (not an easy thing to test without already being in a system) - probably something better learned from a working 2014 Model S.

3) The coolant heater (battery heater) looks like the not intelligent device. Previous suggestions were that a PWM signal to the Front HVJB controlled the power to the heater. My battery (A123 from a 2014 Chevy Spark) already has an integrated heater (controlled locally within the BMS) so I may just be using the heater for cabin heat (assuming I can't get the PTC heater jammed in).

4) The DCDC also has a direct CAN connection. Interestingly in my DCDC there is no Tesla branded board. I'm hoping that the device will simply report CAN out rather than need CAN to operate (at least beyond a 'fail safe' mode). It's only the list of things to test next. I'm also hoping Damien will tackle the DCDC.

Jeff
 

·
Registered
Joined
·
205 Posts
To avoid going too much off topic in the Tesla Battery Heater topic (which of course is related), I have a question about the FHVJB.

What are the dimensions of the box?
(length/width/height) and size of the holes for the incoming power cable.
That allows me to create a dummy and explore possible locations in my car while looking for a FHVJB myself.

And is the corresponding plug for the control connector known?
Edit: sorry, see it mentioned above: Molex 33472-1201
 

·
Registered
Joined
·
141 Posts
What are the dimensions of the box?
(length/width/height) and size of the holes for the incoming power cable...
I've got it up on the bench at the moment.

Front HVJB
L : 9 1/4in case (10 3/4 to allow for LV connector and ground connection)
W: 8 1/4in case (9 1/4 to allow for HV plugs to AC,DCDC,etc. and HV in)
H: 2 3/4in case (3 1/4 if the mounting bracket still fitted)

HV hole size
less than 15mm, hard to get actual without disassembly, probably 13-14mm diameter.

Jeff
 

·
Registered
Joined
·
205 Posts
Thanks!
Perhaps it just fits in between my battery box and motor.

Otherwise somewhere near the contactor box.

The LAPP glands I use are either M16 or M12, but perhaps it’s best to also source the cable and connector.
 

·
Registered
Joined
·
205 Posts
Another question on dimensions (did not get my hands on a box myself).

What is the outer diameter of the cable going into the HVJB?

So the orange cable that has been cut shown on this photo by Kevin.
IMG_2177.JPG

Then I know what gland to use on the other side and design/draw the appropriate hole in my battery box.
Thanks in advance!
 

·
Registered
Joined
·
205 Posts
Finally I've found my FHVJB! I also have a Tesla service manual.
Now the question is, how to use the FHVJB to PWM control the heater?
Unfortunately 1 and ! isn't 2 for me at this stage.
Building on the connector X040 info Kevin shared earlier I'd been expecting 4 wires in the connector. In the box I see 6.
Connector numbering/layout
6/5/4/3/2/1
12/11/10/9/8/7
Then I see:
6 = White
5 = Yellow
4 = Red
12 = Blue
11 = Green
10 = Black
IMG_0671.jpg
Unfortunately besides the HVIL and Thermal controller I cannot find any reference in the wiring diagram that could help me in understanding what is what.
Has anyone already figured this out? Or a suggestion how I could approach this?
 

·
Registered
Joined
·
141 Posts
Front HVJB

inputs that I've tagged (but not verified with operation)

1 - blank
2 - blank
3 - blank
4 - OR 12v (orange)
5 - RD PWM in
6 - BL STAT out (PWM)
7 - blank
8 - blank
9 - blank
10 - BK Gnd
11 - YL-BL HVIL
12 - YL-RD HVIL

Note: also a large ground strap connected to the protrusion/nut just to the left of the low voltage connector

Connector : Molex 33472-1201 (I'm pretty sure)

Jeff
 

·
Registered
Joined
·
205 Posts
Thanks!
On scribd I found an newer version of the Tesla service manuals and those made more sense. I could trace your list back and came to the same conclusion. I think I'm staring to understand things ;) Should have gotten that manual much earlier.

I have measured and can conform the pins 11 and 12 as the HVIL lines.

And answers do trigger new questions:
- Can we do anything with pin 6 (STAT out (PWM))? Curious what kind of signal it will give.
- What are the characteristics of PWM in (pin 5)? Is that just a matter of assuming it's 12V (should be logic in a car) and try different frequencies?
 

·
Registered
Joined
·
141 Posts
And answers do trigger new questions:
- Can we do anything with pin 6 (STAT out (PWM))? Curious what kind of signal it will give.
- What are the characteristics of PWM in (pin 5)? Is that just a matter of assuming it's 12V (should be logic in a car) and try different frequencies?
My plan was to start with a 5v PWM signal, probably starting at 1Hz and working up (faster). Since the PWM is coming from a controller, I suspect they'll use 5v signals rather than a 12v. The Tesla pumps used a 1Hz signal - which caught me by surprise as I was expecting something in the 1kh range. I would guess that there is really only a need to send a PWM with a hertz that's twice as fast as the device can respond anyways. There's got to be some design balance between what is easy for the controller to parse (how easy it is to read the PWM signal) and how often it needs to see changes in the PWM.

I'm guessing the STAT will be something like 0-5v as a signal to the controller (outside the Front HVJB) that the heater is actually responding. Since the heater response is likely to significantly lag the controller instructions.

The control scheme would be something like 1) update the PWM, 2) wait for the STAT to get into the expected range. I feel some interesting tests coming on... pumping some coolant through the heater, sending PWM instructions, and then watching STAT and coolant temps to understand the response.

Jeff
 
1 - 14 of 14 Posts
Top