Sunday, November 30, 2008

Front Components

I got almost all the front components placed very close to where they will go. I reinstalled the front rack, and permanently mounted the vacuum pump and vacuum canister. I test-placed all the other components that will go in the front compartment - the only two items in this picture not in their final location are the Hall effect sensor and the heater contactor:

Here are labels to make it easier to see what is going on:

I'll try to find a box to put the heater contactor in - the guiding principal of the 312V system is to make it very difficult for fingers to come in contact with it.

One problem has become evident - 4/0 welding cable will not fit through the strain relief fittings on the controller. I have a few options:
  • Go with a short run of thinner cable (3/0 might work) - if short enough, should not cause too much of a voltage drop
  • Drill bigger holes and use the 1" LiquiTight flexible conduit terminators I've used elsewhere
  • Just put a rubber grommet on the 1" holes
I'm leaning toward the "drill bigger holes" option right now. Still thinking about it.

Saturday, November 29, 2008

Making Short Interconnects

Today I also started working on the battery interconnects. They will be made from 1/16" by 1" copper bar stock - three pieces for each interconnect. This is so the cross-sectional area (0.1875 square inches) will roughly match the 4/0 welding cable (0.1662 square inches). I could have gone with sold 3/16" by 1" bar stock, but that will be very stiff, and I worry that it will tend to lever the screws out of the batteries as they vibrate.

Anyway, I started with the hardest ones - the short pieces. I cut 24 pieces 3.5" long:

I then bent them to give them a little spring. I started by dividing the bar in quarters:

I then bent both end quarters up by 45 degrees. I used my favorite vice-grip clamps to do this:

Here are the ends bent up:

To create the bend in the middle, I built a little jig. There are two pieces of 3/16" by 1.5" angle stock nailed into a 2/4, and two pieces of 1/8" by 1" angle stock which are the press parts (it's handy that I keep all my waste chunks of metal in a box for future use). I use a bar clamp as the press:

Basically, you insert one of the 1/8" by 1" angle stocks into the valley, then put the copper strap on. Then you put the other 1/8" by 1" angle stock on top, and clamp it down. Screw it down as tight as you can, and you'll end up with a nice 90 degree bend in the middle:

Here are the completed pieces, ready to be drilled and installed:

I should be able to reuse my jig for other 90-degree bends that will be required.

Controller Mounted

I finally got the controller mounted today. First, I finished attaching the mounting bracket I built a while ago. I cut two smaller brackets to attach to the inside front bumper, and bolted them to the Jeep and to the controller mount:

Next, I measured and cut a piece of 1/8" polypropylene to act as a splash guard under the controller:

Here is the splash guard installed, with the vibration isolation feet attaching it to the mounting bracket:

And here is the controller mounted in its final home. At some point, I'm going to shorten that monster 3-phase cable so I don't have to wrap it 17 times around the engine compartment...

Friday, November 28, 2008

Misc Friday

Ahh, Black Friday. A day when every red-blooded American's thoughts turn to... electric conversions. Today was a day for some miscellaneous things I've been putting off for a while. First, I actually installed the "extra" battery mount (one of the first parts I welded). There are three 3/8-16 RivNuts inserted, and three 3/16" by 2" bolts through the rack into the RivNuts. The rack is held level above the sheet metal by three 1" spacers (this was required due to the slope of the fender right next to the mounting point). I also used RivNuts as the top hold-down attachment point:

Next, I made a top for the "extra" battery from polypropylene. Because this battery does not have a rack-style enclosure, I decided to get a little fancy and create a lip around the top to prevent curious fingers from accidentally contacting 312 volts. Basically, I just cut half-way through the box along the edges, and then liberally applied heat with a heat gun. And then, with sufficient force, the edges were bent down:

Next, I reinstalled the heater blower. First, though, I identified the main wire that is hot when the blower is active - it's the light blue wire here. I then added a pigtail blue wire on this so that I can control a relay which gates the heater contactor - I only want the 2000W heater running when there is air flowing:

With some help from KatC, I installed the blower assembly. Here is the view from the engine compartment. The two gold braided wires on the right are the main wires for the heater core. The purple and black lines are the vacuum lines which provide vacuum for the flapper box (TBD - how to hook them up....) And the blue wire is attached to the pigtail I just made:

Finally, I spent some time actually going over the factory service manual wiring diagrams in some detail. This allowed me to determine that some more of the factory harness can go (and should go - it just clutters things up). On the passenger's side, this harness goes to the EGR solenoid, the fuel pump relay, and the "B+" relay (basically, a relay controlling a time delay shutdown circuit). None of those are needed for ElectroJeep, so this whole harness gets guillotined:

On the driver's side, this whole harness which emerged from the bulkhead was entirely dedicated to controlling the gas motor. So, it got chopped. Here you can see the final electrical tape wrapping - basically, each wire gets folded back on itself about 3/4", individually wrapped with electrical tape, and then the whole mess gets taped together:

Tomorrow - weather permitting - I'll reinstall the front rack, finish its holddowns, and start working on battery interconnects (!).

Wednesday, November 26, 2008

Finishing Lower Rear Box Hold-Downs

The last pre-Turkey-Day thing I did was to finish the cover / hold-down. I cut 8 2.5" discs of polypropylene, and countersunk them to install 1/4-20 nylon screws:

I drilled holes through the top (and through the hold-downs where appropriate) and put the bolts on - note - nylon needs to be finger-tight only (I blew up one bolt making it more than finger tight):

Other things evident in this picture but not previously blogged:
  • I cut and installed the 1/8" polypropylene for the sides of the upper rear box
  • I cut, drilled, and painted the hold-downs for the upper rear box (from 3/16" bar stock)
  • I cut and installed the top for the upper rear box
It's getting *very* close to the final battery hookup. I need to:
  • Finish installing the heater (so I can mount the front rack permanently)
  • Permanently install the "extra" battery rack (one of the first parts I welded!)
  • Finish the upper rear, under-seat, front, and "extra" tops/hold-downs just like this
  • Cut lots and lots of 1/16" by 1" copper strap for the interconnect (each interconnect will consist of *three* such straps to allow high amperage to flow without excess heat)

Seat Boxes, IV

I also worked on the under-seat batteries. First, I cut, drilled, and painted a hold-down bar (made of 3/16" bar stock). I also installed threaded rod to hold it down (and a 3/8-16 RivNut in the middle). One note on the threaded rod - it actually goes through the 1/8" angle stock and through the Jeep's sheet metal. Unfortunately, there was not a good flat spot to attach the 3/8" rod - at least, no place where it would stick straight up. So, I just bent it - bending it once should not weaken it (repeated bending would, of course). Here it is:

I cut tops from polypropylene, and drilled holes for the conduit between the two boxes:

Here it is, very nearly complete, with the conduit between the two batteries installed. You can also see the connector for the conduit from the rear rack at the top of the picture, and the connector for the conduit to the engine compartment at the bottom of the picture:

One note - always consult your plans as you cut. You might note that there are *two* cutouts on the box at the bottom of the picture - I had put the batteries in backwards, and cut the openings based on the incorrect orientation of the batteries. As I consulted my plans, I discovered my error, and cut new openings. Not a big deal - but - measure twice, cut once continues to be true...

LiquiTight Conduit

One of the concerns of very high voltage electricity is protecting the cabling from damage. The cable goes outside the Jeep (underneath) at four places:
  1. From the upper rear rack to the under-seat racks
  2. Between the two under-seat batteries
  3. From the under-seat batteries to the front compartment
  4. From the front compartment to the most-positive battery in the upper rear rack
I am using LiquiTight non-metallic conduit for all these interconnects. First, the upper rear rack to under-seat racks - a short run (I later wrote "DANGER: HI VOLTAGE" with some lightning bolts on the conduit):

Second - the cable to the most-positive battery in the lower rear rack. I drilled a hole and installed the connector:

Here is the conduit test-fitted (you can see the first connection at the upper left, and the yellow rear-to-front AC cord dangling in the foreground):

This is a (poor) shot of the conduit going from the rear seat to the engine compartment:

And here is the conduit coming in to the engine compartment. The long piece looped in the compartment will hold the most-positive cable to the lower rear rack (it will get trimmed to length later). The shorter piece at the bottom of the picture goes to the batteries below the rear seat. It looks a little like Doc Octopus is having his way with the engine compartment...

Still do to on the conduit: tie-wrap it to various strategic points on the chassis (making sure to keep it in-board of the unibody "frame-rails" to further protect it from damage).

Charger Mounted

I took the week of Thanksgiving off so I could get more done on the Jeep. Glorious weather - into the 60s most days (I love Colorado...). One of the first things I did was to install the charger for real. A few weeks ago, I inserted 1/4-20 RivNuts where required for mounting the charger. This week, I drilled 3/4" holes in the trim to match the RivNuts, and installed it:

I also put in a junction box. The reason for the junction box is that the 240V input needs to be split in two - one part for the charger, the other part for the 240VAC relay in the front compartment which tells the Jeep not to allow someone to drive it off while plugged in. The orange cord will connect to the charging plug. The yellow cord goes to the front compartment. The black cord goes to the charger:

And then I installed the charger (it was much easier to install the junction box *before* the charger). I have put one LiquiTight conduit connection where the charging cord comes in. I did not get a photo, but I have another one where the yellow front compartment AC cord goes through. I have not yet hooked up the AMP connector for the DC output - need to get all the batteries connected, first (hopefully this week...):

Heater, I

I've been a little lax on the blogging lately - some computer problems on the main family computer slowed me down. All solved now (with a new dual-core processor as well), so, back to blogging.

A couple of weeks ago, I did some major work on the heater. The Jeep's original heater used engine coolant run through a heater core to create the heat. Since the electric motor does not have coolant, a different solution was needed.

As mentioned previously, I obtained two 400V, 1000W ceramic heaters from MorElectric. I also got some high-heat wire, a ceramic terminal block, and ceramic insulation (think fiberglass, but ceramic instead of glass). After extracting the heater core (which was non-trivial - most of the dash needed to be removed) I built a metal box to hold the two heaters, trying to keep it close to the size of the original heater core:

Next, I installed the ceramic insulation. I was careful to wear gloves, eye protection, and a dust mask while doing this - I don't relish the thought of ceramic silicosis...

Nearly done - I installed the ceramic terminal block, hooked up the wires from the heater cores and the new high-temperature 10-gauge wires:

And here it is next to the original heater core:

I test-fit it into the heater box. Not finally installed yet - I'll take some pix and blog it later:

People might notice that I did the heater substantially earlier than I did on the Volt914. The reason is that I need to have the front rack out to access the mounting bolts for the blower box. Much easier before everything is put in place.

Sunday, November 2, 2008

12V Wiring I

I spent some time this week designing and implementing the front 12V system. First, I drew out most of the engine compartment wiring (you can find a PDF here):

I then prepared the relay box. Here it is from the front. You can see the two main relays on the left and right. They are angled this way so the pins will be facing "down"-ish when the box is mounted - I don't trust this box to be 100% water-tight and this will prevent condensation from seeping into the relays. The relay on the left is a 240VAC DPDT relay to handle duties associated with detecting when the charger is plugged in (this is the lower relay in the circuit diagram). The relay on the right is a 12VDC DPDT relay to handle some keyswitch action (mostly: disable the DC-DC converter when the key is switched off):

Here is a view showing the top. There are two rows of 10-place terminal strips. The one in front is row "A" with terminal #1 on the right and #10 on the left. The one in back is row "B". These numbers correspond directly to A1, B2, etc. on the circuit diagram:

There are provisions for 6 keyswitch-controlled and fuse-protected circuits. I am currently using 4. There are also 4 glass fuses for the various signal wires that go out. My current philosophy: fuse early, fuse often. Much easier to replace a fuse than to put out an electrical fire.

Still to do: the charger interlock is drawn correctly on the diagram, but not implemented correctly (the DMOC wants the charger interlock to close a circuit when plugged in; my implementation currently sends a +12V signal, which is not the same thing). Also, this implementation currently disables the DC-DC converter when the Jeep is plugged in. It seems like a good idea to be able to optionally charge up the 12V aux battery when the key is turned on. Again, the wiring diagram above is correct, but the implementation is not quite right yet.

Next up: still have to remove the rest of the dash so I can get at that heater core... you might be able to tell that I am procrastinating on this less-than-fun chore.