[ruckus]

I got a "package" deal from a now defunct EV supplier who no longer responds with tech help. They sent 2 kilovac contactors. I know 1 goes between the bat and the controller for use with the key/ignition switch. (zilla hairball)

The 2nd contactor goes where? Here are possibilities I came up with:

1. place next to contactor 1 as a panic/emergency button on dash.
2. powers up the dc-dc convertor. (but why not use a regular switch for that?)
3. placed halfway through the pack and also hook to the key/ignition. (I find this unlikely in a 96v 260ah TS lifepo4 pack)

Which is correct? I am thinking the emergency button.

What do you think?

It sounds like others have eliminated problems by putting a separate switch on the dc-dc. Turn on the hairball first using the contactor, then switch on the convertor? This also sounds like it allows the car to be switched off completely for long-term storage without bat drain. Am I on the right track?

Also, are the "snubbers" on the contactor sufficient to slow the rush to fill the controller capacitors or do I need other precautions. I seem to remember seeing somebody put a resistor or something similar on the circuit to slow it down. Ideas?

 

[major]

I got a "package" deal from a now defunct EV supplier who no longer responds with tech help. They sent 2 kilovac contactors. I know 1 goes between the bat and the controller for use with the key/ignition switch. (zilla hairball)

The 2nd contactor goes where? Here are possibilities I came up with:

1. place next to contactor 1 as a panic/emergency button on dash.
2. powers up the dc-dc convertor. (but why not use a regular switch for that?)
3. placed halfway through the pack and also hook to the key/ignition. (I find this unlikely in a 96v 260ah TS lifepo4 pack)

Which is correct? I am thinking the emergency button.

What do you think?

It sounds like others have eliminated problems by putting a separate switch on the dc-dc. Turn on the hairball first using the contactor, then switch on the convertor? This also sounds like it allows the car to be switched off completely for long-term storage without bat drain. Am I on the right track?

Also, are the "snubbers" on the contactor sufficient to slow the rush to fill the controller capacitors or do I need other precautions. I seem to remember seeing somebody put a resistor or something similar on the circuit to slow it down. Ideas?

Hi ruck,

Ideas? Read the manual http://cafeelectric.com/downloads/HB202.pdf

Page 23 has a nice schematic. Where it shows a disconnect, you could use the other contactor, or put it in the battery negative feed.

The hairball does the precharge, no external resistor required.

If you have the Kilovac EV200 contactors, there are no snubbers. But probably the coil economizer circuits. http://relays.tycoelectronics.com/datasheets/ev200.pdf

Regards,

major

 

[ruckus]

Thanks for the links.

coil economizer circuits? please do tell...

-have been pouring over the manual for months. Page 23 is quite grubby and wrinkled by now. (does anybody else notice the floating "tach" with no wires?)

Sounds like emergency disconnect is the likely purpose. You also suggest putting (as emergency disconnect) in the neg line. Is this a good practice?

I see some diagrams with the disconnect halfway through the pack, and others have it right next to the fuse or even bolted to the fuse. Could I save on wire/lugs and just bolt the fuse and contactors in line? -contactor-fuse-emergencycontactor-batt+. do they need to be right next to the controller or can they be more by the batts?

also, why no threads in the zilla lugs? wouldn't those help contact area? The manual gives no instructions for major lug connection protocol. Surely this is of great importance to controller/vehicle performance/durability and should be addressed.

Self-threading bolts? Washers or not? Star washers? aluminum? stainless? anti-corrosion gunk? The manual is incredibly brief on these subjects...

If 10-20% of EV power is lost in connections, as some data suggests, then this stuff really matters.

I did read the bottom of page 6 where it says:

VERY IMPORTANT UPDATE! READ THIS!!!
snubber diode this and that OR ELSE!

they also state the necessary wiring may not be shown in the diagrams. ~:|

but you think I should skip the diodes if I have the EV200? that would be nice.

Cheers.

 

[major]

-have been pouring over the manual for months.

Sorry ruck, I run into a lot of guys (especially guys, it seems to be a guy thing) who do not read directions or manuals You do, good for you.

why no threads in the zilla lugs?

I am pretty sure those are copper. Threads in copper are risky. It is a soft metal and the threads can strip with too much tightening torque. These Zilla terminals are rated for 2000A and need a proper tight connection. A thru bolt of proper size and grade with the proper washers, lock washer and nut set to the proper torque need be used. I would have thought a diagram and paragraph in the manual would have been a good idea, but don't recall seeing that.

You ask a lot of basic questions. Not that that is a bad thing Just maybe more than I can handle. And an answer from me generates 3 more questions. Can you find an EV club near your area?

Regards,

major

 

[ruckus]

Hello Major,

Thank you for offering some advice and sorry if I peppered you with more questions.

I do not know of an EV club in my area (Missoula, MT). Also, I would want a broader knowledge base than just how Billiebob has done it before as the EV wiring and components seem to be continually evolving.

Sorry if my questions seem basic, but I see some of the more experienced people on here also going back and questioning basic wiring design (such as whether to switch the dc-dc on at power-up, during charging, or all the time).

I have spent many many hours/months reading threads on here and a few other sites, but they sent a bunch of stuff with absolutely no instructions and now I am on my own to piece this thing together. Since the few manuals are made by people who are experts, the don't realize how much info they are leaving out cause it seems obvious to them.

Maybe it would be a good idea for me to start a build thread. The project is really sweet and if folks can see it, maybe they will want to help with the technical details.

Thanks again,

Marcus

1939 Jaguar SS kit body on a 1968 VW chassis.
ADC 203-06-4001
Zilla Z1K
96v 260ah Thunder Sky batts
EV Power BMS and cell modules for over/under protection.
Chinoz (elcon) 1500w lifepo4 charger
Chinoz (???) 20amp dc-dc

Bat trays are almost done, motor is in and tested. Right now I am mounting all the auxiliary pieces and am running into lots of basic wiring questions (such as if the fuse needs to be right next to the controller, does it have to go in its special holder, or can it use the posts on the contactors?). This is my first build and I am doing it for someone else, so it needs to be done right the first time.

 

[ElectriCar]

The standard it to place one in the + and the other in the - cables coming from the pack into the controller. One of them energizes when you turn the ignition on. The second one is energized via a switch in the pot box. This way there are two methods to kill the power to the controller should it fault at wide open throttle. The reasoning that if only one contactor is used and the contacts were to weld in the on position you couldn't disconnect the power inside the vehicle without a manual disconnecting means.

When you first power on the controller, there may be a surge of current which if large enough could fuse the contacts together rendering that contactor useless. Most pot boxes have a switch in the box for this purpose. You take the + wire off the ignition and connect it to the open or NO contact on the PB, the other connection goes from the other side of that same NO contact to the coil of the second contactor.

 

[major]

The second one is energized via a switch in the pot box.

Actually the Zilla does not use the potbox switch. I never liked to use it even on the old Curtis controllers either.

Everybody has their own way It's like DIY, or DID, Do It Different

I prefer to have a contactor in the negative battery line which turns on by the keyswitch. This will completely isolate the high voltage battery. When the key is turned on, that negative contactor closes and will energize the DC/DC converter and connect HV battery to the Zilla. Then a run switch tells the Zilla (hairball) to energize and it will precharge itself and close the positive contactor. There is also a push to start button for the hairball (see the manual).

note: I also found that if you leave the "SLI+14in" connected on the hairball, it will drain your aux battery over the course of a week or two.

There is no one right way, plenty of ways which will work, and some ways which won't work

major

 

[GizmoEV]

I do not know of an EV club in my area (Missoula, MT). Also, I would want a broader knowledge base than just how Billiebob has done it before as the EV wiring and components seem to be continually evolving.

Roland Wiench posts to the EVDL quite a bit and lives in Great Falls, IIRC. You might send him a PM and ask if he knows of EVers near you who can help. Roland is a retired electrician and has been running EVs for 30+ years and he is very familiar with how the Zilla should be wired up, among other things.

 

[ruckus]

Actually the Zilla does not use the potbox switch. I never liked to use it even on the old Curtis controllers either. major

The pb-6 they sent has a small 3-prong switch on it... I thought that was for telling the controller to ignore the pot at rest, not turning on a contactor. It seems crazy to open a contactor every time you let off the pedal, or am I missing something?

I prefer to have a contactor in the negative battery line which turns on by the keyswitch. This will completely isolate the high voltage battery. When the key is turned on, that negative contactor closes and will energize the DC/DC converter and connect HV battery to the Zilla. Then a run switch tells the Zilla (hairball) to energize and it will precharge itself and close the positive contactor. There is also a push to start button for the hairball (see the manual).major

I like the idea of the neg contactor, but don't quite understand how connecting the neg side could energize the converter if the positive side is still disconnected. I read that folks had issues energizing the dc-dc and the hairball at the same time, so it was recommended to energize hairball, the dc-dc a moment later. You have no trouble? Do you employ an emergency shut off?

note: I also found that if you leave the "SLI+14in" connected on the hairball, it will drain your aux battery over the course of a week or two.major

This vehicle will see periods of rest. slow bat drain must be avoided. I am thinking to put a switch on the 12v bat side, also on the key. A small 12v charger would be tied into the 120v charging input to keep it topped off. It sounds like a common problem for the dc-dc or the hairball to eat up the aux bat. Why do folks use a 12v bat? If you can just power up the convertor with the key, then you have 12v to close the + contactor with the hairball?

There is no one right way, plenty of ways which will work, and some ways which won't work major

I want my setup to be one of the right ways. It sounds like the right ways are few but the wrong ways are many. This seems like a pretty big topic on the forum right now, and a place where many EV's are having trouble.

The person who commissioned the car wants it grandpa simple, super safe, and no chance of it draining down to death if the heater or dome light is left on.

What is the best way to accomplish this?

 

[GizmoEV]

I like the idea of the neg contactor, but don't quite understand how connecting the neg side could energize the converter if the positive side is still disconnected.

If the DC-DC is connected to the negative side of the battery after the contactor and the positive side before the contactor then turning on the key will energize the DC-DC without the contactor on the positive side being connected.

The person who commissioned the car wants it grandpa simple, super safe, and no chance of it draining down to death if the heater or dome light is left on.

What is the best way to accomplish this?

I have no 12V battery in my Gizmo. I have a Sure Power DC-DC that is always connected to the battery pack. It has two 12V lines coming out of it. One is switched and one is always on. It has an extremely low parasitic current drain. I've read that GEM or someone uses this brand because they have never had any warranty claims on them. They make a 96V version. If they made a higher voltage version I'd use it when I do my full size conversion and not use a 12V battery as a back up. It just works!

I've attached the pdf I have of it. If it can handle the loads you have in the EV I highly recommend it. That way, if the dome light gets left on it won't drain a 12V SLI battery to death. If you use LED Dome lights you could leave the light on for a month and still be ok. As for the heater, it should turn off when the key turns off. That is how I have my things wired. Only the radio and dome light work with the key off.

 

[major]

I like the idea of the neg contactor, but don't quite understand how connecting the neg side could energize the converter if the positive side is still disconnected.

Looks like Giz covered that. Thanks

I read that folks had issues energizing the dc-dc and the hairball at the same time, so it was recommended to energize hairball, the dc-dc a moment later. You have no trouble?

I have troubles but that circuit worked just fine. You need to use a separate fuse for the DC/DC (HV side). And I wired in a switch and LED in the "power bay" so if I was working on the system, I could tell the DC/DC was working (LED) and/or turn it off/reset it.

You mentioned installing fuses. Use a proper fuse holder. I recommend strongly against bolting fuses directly to the terminals of other components, like a contactor, for a number of reasons. The contactor ratings are given with a specific cable size attached to the terminals. This is because heat from the internal contact is conducted out via the electrical path. This heat will affect the fuse, and/or vice versa.

Do you employ an emergency shut off?

You betcha Sometimes more than one

Why do folks use a 12v bat?

Safety is one reason. Not that you want to hear it, but a HV battery failure or other failure which blows the main fuse is the most common. Or a failure of the DC/DC. Any of which would leave the vehicle without 12V aux power. Might be a safety problem especially at night. You should have a big enough 12V battery to power things like 4-way flashers for a couple of hours without the HV battery functioning.

Also the 12V battery should reduce the size/rating of the DC/DC because it can handle peak loads. Also your circuit design may require 12V to turn on the DC/DC. Lots of reasons

The person who commissioned the car wants it grandpa simple, super safe,.....What is the best way to accomplish this?

Buy a Nissan Leaf


Regards,

major

 

[GizmoEV]

Looks like Giz covered that. Thanks

You are welcome. You reminded me of a great Pic for my Avatar so now I have one. I'm called Giz by one of the guys who I work with. He is very tall and kept talking about stealing my Gizmo. One day I got him to try sitting in it. Here he is... The top wouldn't even go down all the way with his feet on the ground!

Later he "vandalized it" so I took a picture before cleaning it off.

 

[ruckus]

Thanks for the help everybody!

You have given some good designs. Explicit details were very helpful.

I like how the neg contactor placement completely separates the controller from the battery and charge circuit. If the charger goes poof there is no chance of the zilla getting affected (has that ever happened?) Its not like we can just order up another zilla, I feel lucky to finally ever get one.

I am trying to start a build thread and show some pictures but my computer suddenly is refusing to talk to my camera. and after all these years..

Major, how do you avoid 12v drainage to zilla -put a keyed switch there as well?

Also, you say to use the fuse holder cause the warmth from the contacter may make it blow. Aren't the extra lugs and cable connections just as likely to cause heat? Seems like a lot of folks only use about a 2" cable, will that 2 inches really make a difference? just wondering, it seemed so nice and compact and I see a couple like that in the evalbum. Do you know of anyone who bolted them together and got a failure? I can see that a blown fuse might damage the contactor ($100), whereas with the holder and a few inches, a blown fuse would not damage anything else.

We only have 96v, and an 8" motor. I was going to start with a max of 600A since that is the motor rating. Will I really be blowing fuses and contactors? or course, the big 260ah batteries aren't likely to limit amperage like a smaller battery might.

Cheers

 

[GizmoEV]

The fuse is supposed to be the weakest link in the circuit. This means it has to heat up and melt before anything else does. Because of this need it has more resistance than a regular wire so it will be running hotter than a regular wire would. The contactor also has more resistance than a regular wire so it will run hotter than regular wire. The contactor needs to run as cool as it can so the regular wire connected to it becomes a heat sink for it. If you bolt the fuse directly to the contactor that post on the contactor will not be able to run as cool as it ordinarily could and potentially cause the contactor to wear out or weld easier and it will possibly make the fuse run hotter so it is more likely to blow when there is no short. Also, depending on how your fuse blows it could damage the contactor. Having a short piece of wire between the two will minimize this.

 

[ruckus]

Ok, I will separate with wire and lugs.

Do the contactors and fuses normally get hot under use?
This is not good for efficiency.

What of the busbar tests showing that washers hurt conductivity? are they still needed for long-term reliability of the mechanical connection, even if they hurt the electrical connection.? Paste like crazy?

The local welding shop kinda freaked out when I wanted 0000 cabling and lugs. They have some 000 in stock. Am I crazy to want 4/0?

Any hints on sourcing shielded conduit for use through the passenger compartment along the floor to connect the front and back packs? The owner wants complete emi/rfi shielding for the passenger compartment. Will aluminum/bubble wrap stuff from hardware store work if I ground it to chassis? I was going to coat the firewall and behind the seats to protect passengers.
or should I look for a cable that is already shielded like this: http://www.lscable.com/product/product_info01.asp?cate_code=1324&idx=3
Twist cable and put them in large shielding or shield each and still twist?

sorry, lots of questions... any answers appreciated

 

[major]

Am I crazy to want 4/0?

Yep, I'd say so See this thread http://www.diyelectriccar.com/forums/showthread.php?t=53808

I'd use welding cable. And look for liquid tight metalized conduit from an electrical supply house. Or fab a boxed-in raceway. That nuke power plant stuff will cost an arm and leg And shielding individual cables won't lower RFI like shielding the pair. Twisting ????? I don't.

What else? Oh yeah. Washers? Always use a plated steel washer under the bolt head and under the lock washer. Never put a ferrous washer in the electrical circuit, like between the lug and the fuse tab.

Under normal loads, contactor and fuses don't get very hot, if they are installed correctly. With overloads, they do get hot. There is also vibration and other things to consider. Especially for a guy who isn't sure of what he's doing (no offense), use the recommended methods.

And you mentioned something about 10 to 20% loss in connections. Get real. Things would be a smokin' More like 1%, maybe less, IMO.

Regards,

major

 

[ruckus]

The link suggests I can smoke 2/0 wire at 1c (265A rating). Not reassuring.

-according to this chart: http://www.powerstream.com/Wire_Size.htm
3/0 is rated for 239A
4/0 is rated for 302A

The zilla is supposed to be rated around 300a continuous, so the 4/0 matches that rating. For comparison, the TS260ah batt is happy to dump a continuous 780A at 3c.

4/0 actually seems kinda conservative.
A typical TS 100ah build only puts out 300A at 3c.

If the owner decides to throw in a bigger motor and 8-10 batts in the trunk, I don't want my cabling to be the weak link... :|

It IS registered as a Jaguar, not a "leaf".

 

[major]

The link suggests I can smoke 2/0 wire at 1c (265A rating). Not reassuring.

-according to this chart:http://www.powerstream.com/Wire_Size.htm
3/0 is rated for 239A
4/0 is rated for 302A

The zilla is supposed to be rated around 300a continuous, so the 4/0 matches that rating. For comparison, the TS260ah batt is happy to dump a continuous 780A at 3c.

4/0 actually seems kinda conservative.

A typical TS 100ah build only puts out 300A at 3c. BIG difference! (the 260ah is more than double)

Your motor will be toast before a 2/0 cable fails

But bigger is better. Use 4/0. It'll work.

major

 

[ruckus]

(Sorry, was editing my post to get the numbers straight.)

YES! wimpy 8" motor toast. affirmative sir!

But if he decides to ramp things up and throw in a 11-13" motor and 10 more batts, the 4/0 cables will have been a wise investment, no?

cheers

ps. I am using this heatsink with 2 BIG computer fans. Will that be enough cooling?
http://cgi.ebay.com/ws/eBayISAPI.dl...item=&sspagename=STRK:MEWAX:IT#ht_1206wt_1139
I have not seen similar heat sink in use.

I cut it in half (anybody need a zilla sized sink?) cause it weighed like 30lbs! :eeek:

 

[ruckus]

(Sorry, was editing my post to get the numbers straight.)

YES! wimpy 8" motor toast. affirmative sir!

But if he decides to ramp things up and throw in a 11-13" motor and 10 more batts, the 4/0 cables will have been a wise investment, no?

cheers

ps. I am using a heatsink like this (no warpage) with 2 BIG computer fans. Will that be enough cooling?
http://cgi.ebay.com/ws/eBayISAPI.dl...item=&sspagename=STRK:MEWAX:IT#ht_1206wt_1139
I have not seen similar heat sink in use.

I cut it in half (anybody need a zilla-sized sink?) since it weighed over 20lbs.