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Discussion Starter #1
>From reading through specs of various DC contactors this appears to be an excellent
one for EV use. Could someone guide me to a good vendor carrying this model at a
good price? Thanks
JJ
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Discussion Starter #2
http://www.evsource.com/tls_relays.php

I use one of these in my truck and its great for locating inside the battery box because the contacts are sealed.

----- Original Message -----
From: [email protected]
Date: Wednesday, August 29, 2007 6:41 am
Subject: [EVDL] Tyco LEV200 Series contactor
To: [email protected]

>
>
> >From reading through specs of various DC contactors this appears
> to be an excellent
> one for EV use. Could someone guide me to a good vendor carrying
> this model at a
> good price? Thanks
> JJ
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #3
MIKE WILLMON wrote:

> http://www.evsource.com/tls_relays.php

I notice that at the bottom of this same page, EVSource lists a
KUEP3D15-12 equivalent relay, complete with socket and retaining clip
for a price that is less than Digikey sells the KUEP relay alone for!
This is a great deal, and lets you support one of our EV suppliers while
saving a few bucks to boot.

At only 10A rating, I don't think this relay is quite beefy enough for
heater element switching (as suggested in the item description), but it
is certainly suitable for such tasks as switching pack voltage to the
Curtis KSI input, as was recently covered in another thread.

(For heater switching, something like the beefy P&B PRD-series relays
are more appropriate, though an enclosed relay would be nicer:
<http://relays.tycoelectronics.com/pnb.asp>. )

Cheers,

Roger.

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Discussion Starter #4
I was puzzled about this myself when I was researching relays for my
heater. I ended up getting the package KTA sells (sold) that I
believe John Wayland referred to as the Frankenstien type (because of
the diodes and capacitors hanging off it) that has a 15 or 20 amp
rating.

The topic came up again and I questioned using the KUEP3D15-12 relay
for a 1500 watt heater in a 144 volt system and John W. responded
with the post below indicating he has used one without trouble in a
120 volt system that "technically" would be drawing more than its
rated current.



Roger Stockton wrote:
>
>> http://www.evsource.com/tls_relays.php
>
> I notice that at the bottom of this same page, EVSource lists a
> KUEP3D15-12 equivalent relay, complete with socket and retaining clip
<snip>
> At only 10A rating, I don't think this relay is quite beefy enough for
> heater element switching (as suggested in the item description),
<snip>
> Roger.



Begin copied post from Dec 06:

From: [email protected]
Subject: Re: ***DHSPAM*** Heater (again)
Date: December 3, 2006 7:25:11 PM EST
To: [email protected]
Reply-To: [email protected]

John O'C wrote:


> In that post and this one you refer to system voltages 150v and
> higher.
> With a lower system voltage (144 v for example) it seems the 10 amp
> limit of the relay is approached or exceeded with a 1500 watt
> element. I went with the "frankenstein type" because it has a
> higher rated current limit.
>


JW: OK, understood.


> Is this an overly simplified or otherwise flawed line of thinking?
>
>
JW:
You're correct from a strictly technical aspect, that the current
would be a bit too high for this nifty little relay. At system
voltages lower than 156V, the element's current is higher than the
continuous contact ratings...at 144V it's closer to 11 amps. At 156V
- 192V though, it's a really nice solution being fully enclosed and
far more compact with no open moving parts like the much larger
"frankenstein type".

You mentioned that you had read my posts, thanks. If you had read
some more (I know, there's a lot of them) you would have found that
these relays easily exceed their modest 10 amp ratings. For example,
I used two of these relays in Red Beastie, a 120V machine. I had one
KUEP-3D15-12 relay for each of the two elements that truck had, and
though the current exceeded the contact ratings, there never were any
contact problems in the three and a half years I had the truck.
Subsequently, the truck was sold to East Coast EVer Tony Ascrizzi who
drove the truck through six years of c-c-cold Mass. winters, and he
too, never had a single contact failure with the relays, so that 10
amp current rating, as I said, is conservative. Both relays worked
flawlessly for 8 and 9 years respectively (I had a single element
from '97-'98, then added the second element and relay in '98.).The
only thing that finally did do both of them in, was the terrible
demise of Red Beastie earlier this year in that freak flying dump
truck accident that flattened the Beastie, then burnt the famous
electric truck to a crisp :-(

See Ya.....John Wayland


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Discussion Starter #5
John wrote:

> I was puzzled about this myself when I was researching relays for my
> heater. I ended up getting the package KTA sells (sold) that I
> believe John Wayland referred to as the Frankenstien type
> (because of the diodes and capacitors hanging off it) that has a
> 15 or 20 amp rating.
>
> The topic came up again and I questioned using the KUEP3D15-12 relay
> for a 1500 watt heater in a 144 volt system and John W. responded
> with the post below indicating he has used one without trouble in a
> 120 volt system that "technically" would be drawing more than its
> rated current.

There is no doubt that one can often get away with running devices
outside of their published specs, however, this doesn't mean it is at
all wise to do.

For instance, John W might have found it to work fine because he
happened to use a particular brand relay that happened to be
manufactured in the USA or hadn't yet been overly cost-reduced, and when
someone else follows in his footsteps with an "equivalent" relay or even
the "same" one (but now manufactured in Mexico or China, etc.) they may
find that it fails spectacularly when pushed even a bit beyond its
ratings.

I think you did the wise thing by using a part correctly rated for the
application, and stand by my comment that I don't believe the KUEP3D15
is quite beefy enough for the job of controlling the heater. It
certainly might have adequate current ratings for the heater element in
higher voltage applications, but then its 150VDC rating is exceeded.
One can add additional parts to try to snub the arc and allow the relay
to survive at higher voltages, but when an appropriately rated part is
readily available it just makes more sense to me to buy the properly
rated part and be done with it.

Cheers,

Roger.

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Discussion Starter #6
>
> The topic came up again and I questioned using the KUEP3D15-12 relay
> for a 1500 watt heater in a 144 volt system and John W. responded
> with the post below indicating he has used one without trouble in a
> 120 volt system that "technically" would be drawing more than its
> rated current.
>
>
Okay, I should have read the rest of the thread before responding.
Thanks for the Wayland info. on the relay.

Roger's advice was wise - taking chances with voltage/current ratings is
not the "correct" thing to do from a liability standpoint. That said,
several components are pushed a little over their specs (sometimes quite
a bit!) with "reported" success. You have to decide for yourself if
you're willing to live with the possible consequences.

Listing for the KUEP-style relay on the EV Source website updated to
reflect this line of thinking.

-Ryan
--

- EV Source <http://www.evsource.com> -
Professional grade electric vehicle parts and resources
E-mail: mailto:[email protected]
Toll-free: 1-877-215-6781

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Discussion Starter #7
Roger and all,
> I notice that at the bottom of this same page, EVSource lists a
> KUEP3D15-12 equivalent relay, complete with socket and retaining clip
> for a price that is less than Digikey sells the KUEP relay alone for!
> This is a great deal, and lets you support one of our EV suppliers while
> saving a few bucks to boot.
>
Yeah, that price is current too. Bulk purchasing has its advantages!
> At only 10A rating, I don't think this relay is quite beefy enough for
> heater element switching (as suggested in the item description), but it
> is certainly suitable for such tasks as switching pack voltage to the
> Curtis KSI input, as was recently covered in another thread.
>
Quite a while back, I started using this relay based on information
Wayland provided about the very similar P&B KUEP relay. I just searched
for awhile and couldn't find the reference to this. I did find this
page that makes several references to folks using the relay for heater
operation:

http://www.mail-archive.com/[email protected]/msg07182.html

I have also used the relay without problems for several years, one on
each heater element. Now we just need a high voltage option! One of
the LEV200 Kilovacs (mentioned in the original thread of this
discussion) would work pretty good for not an outrageous price:

http://www.evsource.com/tls_relays.php

Not much larger than the KUEP-style, especially if you need two of
them. The LEV200 would run quite a few heaters by itself!

-Ryan
--

- EV Source <http://www.evsource.com> -
Professional grade electric vehicle parts and resources
E-mail: mailto:[email protected]
Toll-free: 1-877-215-6781

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Discussion Starter #8
I too looked at using the KUEP but couldn't feel comfortable pushing the specs so tight.

I wound up going with the Potter & Brumfield PRD-11DH0-12. I've seen these anywhere from $10-$20 in various places.
Its rated for the task. For more than 120VDC you'd need to get the DPDT version and run serially though both sets of contacts. You'll wind up paying about $15 for a box/cover for this open frame relay.

http://www.relays.shopeio.com/inventory/pdf/PRD.pdf
http://www.relays.shopeio.com/inventory/details.asp?id=735&cat=Relays&sub=

Mike,
Anchorage, Ak.


----- Original Message -----
From: EV Source LLC <x[email protected]>
Date: Thursday, August 30, 2007 4:10 am
Subject: Re: [EVDL] Tyco LEV200 Series contactor
To: Electric Vehicle Discussion List <[email protected]>

> Roger and all,
> > I notice that at the bottom of this same page, EVSource lists a
> > KUEP3D15-12 equivalent relay, complete with socket and retaining
> clip> for a price that is less than Digikey sells the KUEP relay
> alone for!
> > This is a great deal, and lets you support one of our EV
> suppliers while
> > saving a few bucks to boot.
> >
> Yeah, that price is current too. Bulk purchasing has its advantages!
> > At only 10A rating, I don't think this relay is quite beefy
> enough for
> > heater element switching (as suggested in the item description),
> but it
> > is certainly suitable for such tasks as switching pack voltage to
> the> Curtis KSI input, as was recently covered in another thread.
> >
> Quite a while back, I started using this relay based on information
> Wayland provided about the very similar P&B KUEP relay. I just
> searched
> for awhile and couldn't find the reference to this. I did find
> this
> page that makes several references to folks using the relay for
> heater
> operation:
>
> http://www.mail-archive.com/[email protected]/msg07182.html
>
> I have also used the relay without problems for several years, one
> on
> each heater element. Now we just need a high voltage option! One
> of
> the LEV200 Kilovacs (mentioned in the original thread of this
> discussion) would work pretty good for not an outrageous price:
>
> http://www.evsource.com/tls_relays.php
>
> Not much larger than the KUEP-style, especially if you need two of
> them. The LEV200 would run quite a few heaters by itself!
>
> -Ryan
> --
>
> - EV Source <http://www.evsource.com> -
> Professional grade electric vehicle parts and resources
> E-mail: mailto:[email protected]
> Toll-free: 1-877-215-6781
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #9
MIKE WILLMON wrote:

> I wound up going with the Potter & Brumfield PRD-11DH0-12.
> I've seen these anywhere from $10-$20 in various places.
> Its rated for the task. For more than 120VDC you'd need to
> get the DPDT version and run serially though both sets of
> contacts. You'll wind up paying about $15 for a box/cover
> for this open frame relay.
>
> http://www.relays.shopeio.com/inventory/pdf/PRD.pdf
> http://www.relays.shopeio.com/inventory/details.asp?id=735&cat
> =Relays&sub=

A word of warning: not all models in the PRD series are rated for 125VDC
switching! In particular, while the link Mike provides above seems to
offer an amazing price on this relay, the model shown is one without the
magnetic blowouts and is rated only 7A @ 50VDC.

In the PRD-series, one needs a DH or DJ model (e.g. 3DH0-12, 11DH0-12,
etc.) in order to have the 125VDC capability. ('D' specifies DC coil,
and 'H' or 'J' specifies that magnetic blowouts are fitted.)

Also note that the contacts on these relays are polarised, and you must
observe proper polarity when connecting the load to achieve the rated
performance. The datasheet indicates that the model of interest to
EVers that should be readily available from stock is the PRD11DH0-12,
which is a DPST so that one could switch both sides of the heater
element, effectively placing both contacts in series which should double
the voltage rating to 300VDC.

Newark, for instance, has the DPDT PRD11DH0-12 in stock for $38.36/ea
(#18M9286).
Allied has the DPST PRD7DH0-12 in stock for $33.56/ea (#886-0251).

For those interested in rolling their own magnetic blowouts, there are
diagrams near the bottom of the PRD datasheet showing the
orientation/polarity of the blowout magnets relative to the polarity of
the load contacts.

Cheers,

Roger.

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Discussion Starter #10
I am currently using 3 of the 150V Magnecraft relays from EV Source for my
heater. I added resistor/cap arc suppression (but I can still see them
spark in the dark!) and enclosed the relays & fuses in a metal box.

The box is an air conditioning disconnect/fuse box. It holds 2 fuses and 3
relays with a little stuffing :)

2 relays switch 1/2 (each) of a PTC element from a 1500W ceramic space
heater. The 3rd relay switches a full PTC element. As I move the temp
slider on my heater controls, it activates 1/2, then 1, then 2 PTC
elements. My pack voltage is 114V nominal.

On my next conversion I'll probably use the LEV200. It's a bit spendy, but
it's small and easy. It also works well for higher pack voltages :)

-Adrian

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Discussion Starter #11
>> The topic came up again and I questioned using the KUEP3D15-12 relay
>> for a 1500 watt heater in a 144 volt system and John W. responded
>> with the post below indicating he has used one without trouble in a
>> 120 volt system that "technically" would be drawing more than its
>> rated current.

John is using a ceramic heater; they usually draw much less current than
their ratings indicate. So, I wonder whether he really is switching 1500
watts.

I also believe he has an RC snubber across the contacts. That helps a lot.

Roger Stockton wrote:
> There is no doubt that one can often get away with running devices
> outside of their published specs, however, this doesn't mean it is at
> all wise to do.
>
> For instance, John W might have found it to work fine because he
> happened to use a particular brand relay that happened to be
> manufactured in the USA or hadn't yet been overly cost-reduced, and when
> someone else follows in his footsteps with an "equivalent" relay or even
> the "same" one (but now manufactured in Mexico or China, etc.) they may
> find that it fails spectacularly when pushed even a bit beyond its
> ratings.

Besides this, a relay's contact ratings are based on some particular
load and life. A typical spec written on the relay might be "120vac
10amps". But the full spec on the data sheet is "120vac 50/60hz 10amps
resistive, for 100,000 cycles". Unlike semiconductors that fail almost
immediately when overloaded, when you exceed the ratings of a contact,
it degrades rather gracefully. John may be overloading the relay by 2:1,
and shortening its life to 10,000 cycles; but he still hasn't switched
his heater on/off 10,000 times.

> when an appropriately rated part is readily available, it just makes
> more sense to me to buy the properly rated part and be done with it.

Exactly. This is the essence of conservative design. Make it strong
enough so you don't have to worry about failure.

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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Discussion Starter #13
--- James Massey <[email protected]> wrote:
[snip]
> The test I did last year to answer the "how much
> does a ceramic heater
> draw?" question is that really cold (out of the
> refrigerator) it drew only
> 10 to 15% or so of what it did when hot, so contact
> closure on a cold
> ceramic heater is not stressful at all. (I've
> mislaid the data for now, but
> it'd be in the posting archives).
>
> On opening it depends on the temperature of the
> heater - there is a very
> distinct "knee" when the heater goes past the
> maximum power temperature,
> over the next 10 or 15 degrees (Celcius) or so its'
> resistance climbs
> amazingly. Once the heater is 20 degrees past the
> maximum power point it is
> back to a low current condition. (I'd completely
> beleive the claims that a
> ceramic heater in a properly rated housing will not
> be a problem with no
> airflow - I had a heater element in between two fire
> bricks and once I
> reached a certain point I couldn't get it to go any
> hotter, despite a huge
> increase in the voltage applied).

I remember reading on one of the Tesla Motors' blogs
that they used a ceramic heater because it had an
automatic maximum heat because the resistance would
climb to the point that the element wouldn't overheat.



David D. Nelson
[email protected]



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