# [EVDL] Shunts



## EVDL List (Jul 27, 2007)

In a message dated 9/17/2007 8:19:01 PM Central Daylight Time, 
[email protected] writes:

Any good sources for meter shunts? What is the typical resistance for a 
1000 Amp shunt?

A 1 milliOhm shunt at 1000 Amps will be dissipating 1000 watts! That seems 
too high.

So 0.1 milliOhm?? Can a shunt be reasonably made??



Thank you,

Dave Delman
1981 Electric DeLorean Project
electricdelorean.com



A 50mv 1000 amp shunt would be 50 micro Ohms and would dissipate 50 watts at 
1000 amps.

A 1000 amp 50 mv shunt is available at EVParts: 
(_http://www.evparts.com/shopping/index.php?id=602_ (http://www.evparts.com/shopping/index.php?id=602) 
(http://www.evparts.com) ). 

Ken




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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

On the subject of shunts, can they serve double duty? I have a shunt in line for my eMeter, could
I hook up another device (ammeter) to this without affecting the eMeter?

Dave Cover, stepping forward after my last step back



> --- [email protected] wrote:
> 
> > In a message dated 9/17/2007 8:19:01 PM Central Daylight Time,
> > [email protected] writes:
> ...


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

.001ohms * 1000A = 1volt That is how you are getting 1000Watts

But most shunts are 50-100mv at full scale so a 1000A shunt is 1000 *
.050 or 1000 * .100 or 50-100W. peak.

You can only put that much thru the shunt for a limited amount of time.
I'd be surprised if you can get 1/2 of that on average
So you are probably only talking 25Watts or less. (Could of just not had
that second helping of cake)

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## EVDL List (Jul 27, 2007)

"50mV at full scale" is common for shunts... so a 250A shunt is 0.0002
ohms. There are lower resistance shunts still.

In general you should be able to hook up a second device to the same
shunt. Do not splice into the sensing wires, just screw new ones onto
the shunt.

Danny

----- Original Message -----
From: Dave Cover <[email protected]>
Date: Monday, September 17, 2007 9:02 pm
Subject: Re: [EVDL] Shunts
To: Electric Vehicle Discussion List <[email protected]>

> On the subject of shunts, can they serve double duty? I have a 
> shunt in line for my eMeter, could
> I hook up another device (ammeter) to this without affecting the 
> eMeter?
> Dave Cover, stepping forward after my last step back
> 


> > --- [email protected] wrote:
> >
> > > In a message dated 9/17/2007 8:19:01 PM Central Daylight Time,
> > > [email protected] writes:
> ...


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## EVDL List (Jul 27, 2007)

Hi all,

I have a customer seeking a neat 75mV 500A shunt to replace one he's 
not particularly happy with - searching "75mV 500A" on eBay shows you 
the sort of shunt he's currently got (big nickel-plated shunts with 
black vertical strips, made in China).

He'd prefer something like the Deltec shunts (more compact, with 
integrated mounting block) but they only seem to come in 50mV and 
100mV. Is anyone aware of any other sources I might be able to look 
into? (Preferably just the shunt, since he already has the 75mV 500A 
meter to suit.)

TIA,

Ian Hooper
[email protected]

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## EVDL List (Jul 27, 2007)

they appears on Ebay often, i have purchased mine from here

Philippe


2008/4/28, Ian Hooper <[email protected]au>:
>
> Hi all,
>
> I have a customer seeking a neat 75mV 500A shunt to replace one he's
> not particularly happy with - searching "75mV 500A" on eBay shows you
> the sort of shunt he's currently got (big nickel-plated shunts with
> black vertical strips, made in China).
>
> He'd prefer something like the Deltec shunts (more compact, with
> integrated mounting block) but they only seem to come in 50mV and
> 100mV. Is anyone aware of any other sources I might be able to look
> into? (Preferably just the shunt, since he already has the 75mV 500A
> meter to suit.)
>
> TIA,
>
> Ian Hooper
> [email protected]
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>
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## EVDL List (Jul 27, 2007)

> they appears on Ebay often, i have purchased mine from here
>
> Philippe

If he has one like this: 
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250241133623
they look neat enough. Would be nice to have a non-conductive block 
attached at the bottom for mounting, or how about a clear tube 
(http://electroauto.com/catalog/elec.shtml#fuselink) to protect from 
contact?

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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

> Ian Hooper wrote:
> > Hi all,
> >
> > I have a customer seeking a neat 75mV 500A shunt to replace one he's
> ...


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## EVDL List (Jul 27, 2007)

Along the same vein, I picked up a shunt for the motor side of my
controller, 50mv/1000Amps. I wanted to measure the current my controller
could handle and came across a shunt first. I had been watching for a lon g
time before this option came along. The problem I'm finding is no one makes
a meter to match the shunt.

I've been watching eBay as well as the usual sources; DigiKey, Mouser,
SurplusStore, etc. I just can't find a compatible meter. I'd even go with a
50mv/100A meter, but haven't seen one. It seems all the meters in my range
work at 75mv for the top end.

Since you already have a meter, you know what shunt you need. My problem is
I can't find a meter to match my shunt. Go figure. If I'd have known how
incompatible these can be I wouldn't have jumped on it so quickly.

Dave Cover



> Zeke Yewdall <[email protected]> wrote:
> 
> > I've only seen ones that are 50mV/500A and 100mV/100A (Occasionally
> > 100mV/150A or 50mV/100A). I suppose you could use two of the
> ...


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## EVDL List (Jul 27, 2007)

You could always use a standard 50mV/500A meter, and remember that
it's only reading half of the actual amperage......

Z



> dave cover <[email protected]> wrote:
> > Along the same vein, I picked up a shunt for the motor side of my
> > controller, 50mv/1000Amps. I wanted to measure the current my controller
> > could handle and came across a shunt first. I had been watching for a lon g
> ...


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## EVDL List (Jul 27, 2007)

>
> The easiest solution is to get a 100mv shunt, and connect a resistor in
> series with the meter to drop the extra 25mv (so he gets 75mv at the meter).
>

That's pretty tricky, since you'd have to know exactly how much
current the meter was drawing. I'm not familiar with the particular
one he has, but the ones I've used are very low current -- like
microamps, on the sense inputs. If the meter doesn't have seperate
sense and power inputs, the current draw could be up in the mA range,
but could also vary depending on how many digits of the display are
lit up, which won't work.

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## EVDL List (Jul 27, 2007)

I think if it is analog Lee 1s correct, 1/3 the resistance of the meter in
series will the meter should do it. It's volts at this point not amps, the
current will be very low. If it is a digital meter then a resistor bridge of
two resistors will do. Something like 100 ohms and 33 ohms in series across
the shunt and then the meter across the 100 ohm resistor.

Mark Grasser


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Zeke Yewdall
Sent: Monday, April 28, 2008 11:49 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Shunts

>
> The easiest solution is to get a 100mv shunt, and connect a resistor in
> series with the meter to drop the extra 25mv (so he gets 75mv at the
meter).
>

That's pretty tricky, since you'd have to know exactly how much
current the meter was drawing. I'm not familiar with the particular
one he has, but the ones I've used are very low current -- like
microamps, on the sense inputs. If the meter doesn't have seperate
sense and power inputs, the current draw could be up in the mA range,
but could also vary depending on how many digits of the display are
lit up, which won't work.

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## EVDL List (Jul 27, 2007)

I believe you can get one of these from KTA and or Electro Automotive.

---- dave cover <[email protected]> wrote: 
> Along the same vein, I picked up a shunt for the motor side of my
> controller, 50mv/1000Amps. I wanted to measure the current my controller
> could handle and came across a shunt first. I had been watching for a lon g
> time before this option came along. The problem I'm finding is no one makes
> a meter to match the shunt.
> 
> I've been watching eBay as well as the usual sources; DigiKey, Mouser,
> SurplusStore, etc. I just can't find a compatible meter. I'd even go with a
> 50mv/100A meter, but haven't seen one. It seems all the meters in my range
> work at 75mv for the top end.
> 
> Since you already have a meter, you know what shunt you need. My problem is
> I can't find a meter to match my shunt. Go figure. If I'd have known how
> incompatible these can be I wouldn't have jumped on it so quickly.
> 
> Dave Cover
> 
>


> Zeke Yewdall <[email protected]> wrote:
> >
> > > I've only seen ones that are 50mV/500A and 100mV/100A (Occasionally
> > > 100mV/150A or 50mV/100A). I suppose you could use two of the
> ...


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## EVDL List (Jul 27, 2007)

Ah, I didn't even consider the possibility of it being an analog
meter. I just assumed it was an e-meter/link10 type device. Ooops.

I don't think the resistor bridge will work to increase the voltage --
if we wanted a lower signal voltage than what the shunt is giving, we
could use it to decrease the voltage though. Any other EE's want to
weigh in on this?

Z



> Mark Grasser <[email protected]> wrote:
> > I think if it is analog Lee 1s correct, 1/3 the resistance of the meter in
> > series will the meter should do it. It's volts at this point not amps, the
> > current will be very low. If it is a digital meter then a resistor bridge of
> ...


----------



## EVDL List (Jul 27, 2007)

> Zeke Yewdall <[email protected]> wrote:
> > Ah, I didn't even consider the possibility of it being an analog
> > meter. I just assumed it was an e-meter/link10 type device. Ooops.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

I was responding to the question of how to use a 100mv shunt with a 75mv
meter. Either resistor method should work. The only way to use the 50mv
shunt would be to use some type of amplifier circuit. Incidentally, 1000amps
= a .1volt drop across the 100mvshunt. That 100 watts of heat. You will need
to be moving some air if you are going to do it very often.

Mark Grasser



-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Zeke Yewdall
Sent: Monday, April 28, 2008 1:01 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Shunts



> Zeke Yewdall <[email protected]> wrote:
> > Ah, I didn't even consider the possibility of it being an analog
> > meter. I just assumed it was an e-meter/link10 type device. Ooops.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Okay. We agree  I thought you were referring to the 50mV shunt.

yeah... that's alot of heat for a little shunt to dissipate. I've
never actually seen a shunt rated at any more than 500 amps, and those
are 50mV ones, so only 25 wattts there. But, apparently there are
bigger ones out there.

Z



> Mark Grasser <[email protected]> wrote:
> > I was responding to the question of how to use a 100mv shunt with a 75mv
> > meter. Either resistor method should work. The only way to use the 50mv
> > shunt would be to use some type of amplifier circuit. Incidentally, 1000amps
> ...


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## EVDL List (Jul 27, 2007)

I talked to a representative of a shunt company, and he said that the
rating listed on the shunt is the *continuous* rating, and they should
be able to handle much more peak current.

-Morgan LaMoore



> Zeke Yewdall <[email protected]> wrote:
> > Okay. We agree  I thought you were referring to the 50mV shunt.
> >
> > yeah... that's alot of heat for a little shunt to dissipate. I've
> ...


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## EVDL List (Jul 27, 2007)

Maybe his shunts, depends how they rate them. I have melted the solder out
of shunts, turned them blue, even made them blister, never more than 25%
over the rating. Of course the ones I used came from "that place".

Mark Grasser
Balyntec
Marine Products, LLC
828-581-4601
[email protected]


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Morgan LaMoore
Sent: Monday, April 28, 2008 2:11 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Shunts

I talked to a representative of a shunt company, and he said that the
rating listed on the shunt is the *continuous* rating, and they should
be able to handle much more peak current.

-Morgan LaMoore



> Zeke Yewdall <[email protected]> wrote:
> > Okay. We agree  I thought you were referring to the 50mV shunt.
> >
> > yeah... that's alot of heat for a little shunt to dissipate. I've
> ...


----------



## EVDL List (Jul 27, 2007)

Take a look at this 100A meter (you have to multiply by 10):

http://www.allelectronics.com/cgi-bin/item/PMD-100A/385/100_AMP_DC_PANEL_METER_.html

They don't say how many mV it is, but they also sell a 100A 50mV shunt, 
so my guess is...

- SteveS

Zeke Yewdall wrote:
> You could always use a standard 50mV/500A meter, and remember that
> it's only reading half of the actual amperage......
>
> Z
>
>


> dave cover <[email protected]> wrote:
> >
> >> Along the same vein, I picked up a shunt for the motor side of my
> >> controller, 50mv/1000Amps. I wanted to measure the current my controller
> ...


----------



## EVDL List (Jul 27, 2007)

> dave cover wrote:
> > Along the same vein, I picked up a shunt for the motor side of my
> > controller, 50mv/1000Amps. I wanted to measure the current my controller
> > could handle and came across a shunt first. I had been watching for a lon g
> ...


----------



## EVDL List (Jul 27, 2007)

>> The easiest solution is to get a 100mv shunt, and connect a
>> resistor in series with the meter to drop the extra 25mv (so he
>> gets 75mv at the meter).



> Zeke Yewdall wrote:
> > That's pretty tricky, since you'd have to know exactly how much
> > current the meter was drawing.
> 
> ...


----------



## EVDL List (Jul 27, 2007)

> Morgan LaMoore wrote:
> 
> > I talked to a representative of a shunt company, and he said
> > that the rating listed on the shunt is the *continuous*
> ...


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