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Discussion Starter · #1 ·
Re: [EVDL] detecting the smoke before it gets out of hand duringcharging (long)

Hello Chuck,

In commercial areas, we install a combination smoke and fire detectors. This
detector can be purchase at electrical supply stores, alarm stores and the
large hardware stores. I use the type that uses both 120 VAC and a 9 volt
re-chargeable battery or from a remote battery circuit. This device has a
built in switching contact for any remote alarms.

This alarm switch can be use to turn off a AC magnetic 2 or 3 pole contactor
that can be fitted with any size voltage coil from 24 vac or more. This type
of device is normally call a lighting contactor that have sizes for 30 or
more amp which can be use to turn off your charger. You can get a added
power pole that has a normally close and normally open contacts for this
type of contactor, which can also switch on any remote alarms. Thi

Another way to do this power off, is to purchase a circuit breaker power
handle which can attach to some circuit breakers. These units are power by
24 vac source that can be activated by alarm switch.

You can get a added power pole for this type of contactor, which can also
switch any remote alarms.

You can get alarms that work off the speaker circuits. You can get them
from a electronics supply shop. These units are about 1 inch in diameter
and about 2 inches long with two leads coming out of a built in pipe nipple
which can be mounted to a standard junction box plate.

These units emit a sonic sound which will be lower with a low voltage to it
or higher ear splitting with a higher voltage. You can get models with a
steady sound or with a warbling sound.

If your EV is in a garage with ICE's, then use this type of smoke detector
without the battery and only with the 120 VAC power. Put a switch on this
120 VAC line to shut the detector off while you not charging. You could
also install a limit switch on the garage door, so any time a ICE comes in,
it will turn off the alarm circuit.

You could have the alarm circuit come back on by using a ON DELAY relay in
this garage door circuit, so as to let the ICE exhaust dissipate for a
while, before the alarm is power up again. In commercial garages, there may
have exhaust fans come on for a set period of time which is also control by
a CO2 detector.

The AC Magnetic Contactors have holding contacts where you can wire it for
the coil to be energized by a control station with a maintain switch contact
or a momentary switch contact as we use in out momentary push button
stations.

You can wire the AC contactor where when the smoke detector looses AC power
from the circuit from the garage door limit switch, it will not turn off the
charger.

If you install this door limit switch in the auxiliary alarm circuit that
goes to your remote alarm, it will only turn off that alarm, but the smoke
detector will emitted its own sound which you will have to reset.

Roland


----- Original Message -----
From: "Chuck Hursch" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, March 22, 2011 2:56 PM
Subject: [EVDL] detecting the smoke before it gets out of hand
duringcharging (long)


> (This is a bit long, sorry; my technical ? is in the last paragraph.)
>
> With the uproar over the recent SRJC EV fire, it seems like I hear very
> little about detecting and stopping a charging smoke/fire. Maybe it
> isn't sexy, I don't know, but in my 10-15 years of nearly continuous
> reading of the List, it's seems rarely talked about.
>
> Playing devil's advocate ;^>: while gasoline refueling deals with a
> very flammable substance, it is done quickly and under supervision, ie.
> someone is watching all the time. You're basically filling a can with a
> liquid, which is pretty darned simple. In contrast, the EV
> battery-charging process seems a heck of a lot more complicated. You've
> got charger this, BMS that, and batteries too. Drags on and on, hour
> after hour. Unattended for most of the time.
>
> EV-charging smoke and fire events are nothing new. OEM vehicles can
> partake too. I have some recollection of hearing of an EV1 fire or two,
> ostensibly because the charging port overheated. More recently, a GEM
> fire burnt up the side of a building down in SF's Presidio. Then
> reading the SRJC thread, I saw mention of an EV fire in Petaluma,
> presumably during charging (but it didn't say as I recall), that I
> hadn't heard about. And now the SRJC fire (how it happened isn't
> apparent).
>
> There's always something that can go wrong and cause a charging smoke
> event. Your charger's bouncing down the road along with the rest of the
> car, along with your BMS. Batteries... Maybe that last pothole cracked
> a circuit board somewhere, so your BMS now cooks your (lithium)
> batteries. A surge/sag comes down the powerline and scrambles your
> electronics. A charging port/connector not inserted quite right,
> leading to a high-resistance connection. A little oxidation in a
> connection starts the vicious cycle of heat and more oxidation, and on
> it goes till it gets hot enough to... How many other ways can something
> go wrong? It all has to work, no screwups allowed!
>
> When I was getting into EVs back in the early and mid-90s, one of my
> concerns was having a fire during charging, like overnight when I'm
> snoozing. I remember bringing this up during a NBEAA meeting(yes, the
> same one associated with this SRJC car, but almost all different
> people). I asked the question of the speaker. Out the corner of my
> eye, I caught site of one of the chapter officers giving me the "shoosh"
> signal. Let's sweep it under the rug, shall we? Not good enough!
>
> I've been fortunate. I've never had a smoke event, except the one time
> when I first had my EV, I was at the garage of the friend/EV'er who had
> helped me build my car, and I had the K&W BC-20 cranked up for some
> time. I went to unplug it, and smoke came pouring out of the female
> connector at the charge "port" (basically a 5-15 connector). I still
> laugh to this day when I remember Preston leaping over to the other end
> of the cord to unplug it. But other than that, no smoke. I'm very
> careful, and I check the car (sniffer is on alert, feel
> charger/connections/cordends, everything sound right and acting ok?)
> after it's been charging for awhile before I turn in for the night.
>
> All that said, I do have a standard smoke detector on the shelf that I
> bought for experimenting with to install in the car. My goal is not to
> have a screeching (perhaps false alarm) smoke detector. I'm thinking
> something more that will just shut the charging process off via a relay,
> and more recently, send an alert to the computer display up in the apt
> (or wherever). I planned on partially dissecting the charger, tossing
> the speaker or whatever it is that makes that horrendous noise, and see
> if I can drive a relay off of that speaker connection. One what
> would've been a speaker chirp would trip the otherwise-closed relay.
> Once I've got the relay working, I can do what I want. Anyone done this
> before, or am I barking up the wrong tree trying to run off the speaker
> wires? It shouldn't be too hard to just try it out, but I'd have to
> track down a suitable test relay (suggestions?). I'd put one smoke
> detector in the back near the charger, and perhaps one up under the hood
> somewhere to keep track of the numerous fuses and connections up there.
> There's also the issue of a trip when the FLAs reach the gassing
> point, but whether the gassing is strong enough to cause a trip is
> probably not the case. Also, I understand ICE exhaust can set off smoke
> detectors.
>
> No smoke, thankyou,
> Chuck
>
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Discussion Starter · #2 ·
Re: [EVDL] detecting the smoke before it gets out of hand duringcharging (long)

Chuck Hursch wrote:

> - A few months ago, I was searching for a 120VAC relay that can handle
> more amps than my current 15A timer setup. I really think I need to
> feed my batteries more amps than the 8.5-9A DC I'm currently giving
> them. So initially, I found a 25A relay some months ago on the internet
> (URL is lost, but I'm sure I can find a suitable relay). That ought to
> handle the 17-20A the Zivan is going to suck from the line. That will
> be the power relay.

Have you looked at the relay offered by the miniBMS guy?
http://minibms.mybigcommerce.com/products/Solid-State-AC-Relay-40-Amp.html
http://is.gd/YOWIVx

With the 20 amp relay in my EVPower BMS, I can run a Zivan 3KW plus a
1.5KW. With the 40 amp relay, I should be able to run up to 9KW. Or
more.

--
Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 193 days 2 hours 49 minutes

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Discussion Starter · #3 ·
Re: [EVDL] detecting the smoke before it gets out of hand duringcharging (long)

On 3/24/2011 4:49 AM, Willie McKemie wrote:
>
Chuck Hursch wrote:
>
>> - A few months ago, I was searching for a 120VAC relay that can handle
>> more amps than my current 15A timer setup. I really think I need to
>> feed my batteries more amps than the 8.5-9A DC I'm currently giving
>> them. So initially, I found a 25A relay some months ago on the internet
>> (URL is lost, but I'm sure I can find a suitable relay). That ought to
>> handle the 17-20A the Zivan is going to suck from the line. That will
>> be the power relay.
>
> Have you looked at the relay offered by the miniBMS guy?
> http://minibms.mybigcommerce.com/products/Solid-State-AC-Relay-40-Amp.html
> http://is.gd/YOWIVx

Appears to be controlled by 3-32VDC, while I want to control with
120VAC. But I think I found a tree to bark up over at amazon (for
instance this or related:
http://www.amazon.com/gp/product/B00481S3QK/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B00481XRA2&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1ZD0BYQCQC2TD8M5Q7R2

or tinyurl: http://tinyurl.com/4kut78q

The timer relay will output 120VAC, and the relay controlled by the
"smoke detector" would also output 120VAC.

The timer and smoke detector relays will be daisy-chained to control the
120VAC input to the big power relay that controls the charger on/off.
>
> With the 20 amp relay in my EVPower BMS, I can run a Zivan 3KW plus a
> 1.5KW. With the 40 amp relay, I should be able to run up to 9KW. Or
> more.
>

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