[Nick Smith]

Just came across a new draft document for EV conversions on the LVVTA website. Submissions are open until 31-march-2011.

Please give the document a read and get your comments in!

http://lvvta.proboards.com/index.cgi...lay&thread=135

[evlowrider]

Originally Posted by Nick Smith

Just came across a new draft document for EV conversions on the LVVTA website. Submissions are open until 31-march-2011.

Please give the document a read and get your comments in!

http://lvvta.proboards.com/index.cgi...lay&thread=135

It all looks reasonable except for the following items:

Instrumentation

2.4(1) The instrumentation of an electrically‐powered low volume vehicle must provide
to the driver, a clear visual indication of:

(d) in the case of a vehicle fitted with an electric vacuum pump, a loss of vacuum that may result in a loss or reduction of braking performance;

(f) the occurrence of a ground fault (isolation failure), accompanied by an
audible warning.

So I need a vacuum gauge hooked up to a warning light? and wtf?

Accelerator

2.4(2) An electrically‐powered low volume vehicle must have an accelerator pedal, and
an associated control mechanism for the control of the electrical motor and circuitry, incorporating a fail‐safe design.
"A single potentiometer type mechanism is not acceptable as a means of compliance with 2.4(2)."

Are they implying we need some sort of dual pot setup with redundancy or failover? I don't know how to pass this one.

Anyone else submitted feedback to this document?

Pete.

[Nick Smith]

Originally Posted by evlowrider

It all looks reasonable except for the following items:



So I need a vacuum gauge hooked up to a warning light? and wtf?

I think a vac pressure switch would do. Just need a tee in the line to the vac pump and a simple SMC vacuum switch. This statement is also inconsistent with the braking assist paragraph, which mentions vacuum and air. What about an air pressure failure? Neither paragraph mentions any other type of brake assist i.e. hydraulic.
I think the whole paragraph should be less specific and simply require a braking assistance failure warning.

Are they implying we need some sort of dual pot setup with redundancy or failover? I don't know how to pass this one.

I would hope that hall effect pedals would be OK as they are (supposedly) failsafe. I think the comment is in reference to pot boxes specifically as they can wear a "spot" on the most commonly used throttle position.
The discussion document covers the need for redundancy

Anyone else submitted feedback to this document?

Pete.

I actually have the greatest resistance to the warning sitcker on the bumper! In my opinion it signals that my vehicle is somehow unsafe and inherently dangerous.

Will petrol cars need to have a "flammable" sticker attached - I think not.

Something else that kind of slips in - how do you detect whether a ventilation fan is working or not? I did find some Omron resistive flow sensors on RSnewzealand but they start at 120 bucks and go up from there.

[MaverickNZ]

Vacuum failure shouldnt be too bad as it is just a low pressure switch on the vacuum reservoir.

The single pot throttle always worried me a little as it is a basic weak point in the system. Dual pots with one that say increases in voltage the more the pedal is pressed and the other that decreases could be compared to determine if the throttle pot has failed. I can understand what they are trying to do this this piece but it could be made clearer on what they are looking for with regards to "failsafe".

I too am a little annoyed with the need for EV warning stickers. As it has been said it makes an EV sound more dangerous than an ICE car which is completely wrong. Most high voltage stuff needs warnings on it anyway doesnt it?

One good point from this I see if the removal for the need to vent batteries if they dont produce gases during charging. It might still be required to keep them cool during charging though. With regards to ventalation fans brushless DC fans are theoretically spark proof so could be used. If the large 120mm computer BLDC fans are used some of them have a tachometer wire coming from them so the PC knows if it fails. This or something similar could be used in an EV ventalation system.

Ryan Gibbs

[rwt33]

I completely agree with the thoughts on the label too.
I know someone who got around it with their last conversion by pointing out that hybrids don't have some fancy sign that turns on and off depending on if they're running on electric or not!

[Nick Smith]

Something else to watch out for is that all cars from 1992 on will have to comply with the new requirements. I would hope that all owners of registered ev will be contactd but wjat this means in terms of compliance costs is not clear.

In the building industry they have documents outlining "acceptable solutions". Perhaps we will need to develop ansimilar document for EV converters too. As far as anything goes, we should at least demand consistency between OEM vehicles and our conversions. Much of the stuff in the draft standard is following this approach (and sort of assumes scratch build rather than conversion) so that is particularly why I disagree with the bumber sticker requirement.

I personally welcome the new document even if some might roll their eyes and complain about the costs or complexity of compliance. The last thing we want is for these vehicles to be considered dangerous, or worse still - BANNED.