EV Digest 6397
Topics covered in this issue include:
1) RE: wiring size
by "Roger Stockton" <[EMAIL PROTECTED]>
2) Re: wiring size
by "FRED JEANETTE MERTENS" <[EMAIL PROTECTED]>
3) RE: wiring size
by "Peter VanDerWal" <[EMAIL PROTECTED]>
4) Re: Question about 20 gauge fusible link, what is the blow current in amps?
by "FRED JEANETTE MERTENS" <[EMAIL PROTECTED]>
5) Re: wiring size
by "Peter VanDerWal" <[EMAIL PROTECTED]>
6) Re: RE
by "FRED JEANETTE MERTENS" <[EMAIL PROTECTED]>
7) RE: wiring size
by "Peter VanDerWal" <[EMAIL PROTECTED]>
8) Re: Regs? Opinions Please?
by Matthew Milliron <[EMAIL PROTECTED]>
9) Re: wiring size
by "Paul G." <[EMAIL PROTECTED]>
10) Re: wiring size
by "Peter VanDerWal" <[EMAIL PROTECTED]>
11) Re: wiring size
by "Peter VanDerWal" <[EMAIL PROTECTED]>
12) Re: RE (was crimping?)
by "Peter VanDerWal" <[EMAIL PROTECTED]>
--- Begin Message ---
Paul G. wrote:
> I thought he was suggesting that the *acceptable* voltage drop is
> usually considered as a percentage of the applied voltage.
I think you are correct. I had to search waaay back to find (what I
think to be) Roland's original statement:
>> >> > A 1/0 copper stranded wire that has a insulation rating of 90
>> >> > degrees C or 194 degrees F is good for 170 amps continuous
>> >> > with a 3 percent voltage drop.
I think that this sort of statement is usually intended to mean that the
cable can carry the specified current at the specified temperature, and
the maximum *length* of the cable will be limited by the maximum
tolerable voltage drop (specified as a % of the applied voltage, i.e. as
a % drop).
I don't think there is an accepted value for voltage drop in our EV
wiring, but we tend to use welding cable for our traction wiring and so
manufacturer's charts specifying its ampacity often show maximum run
lengths vs current based on accepted values of voltage drop for welding
applications.
> If 3% is taken as an acceptable number (I'm not sure exactly what is
> acceptable) then a 96 volt EV running at 200 amps can use smaller
> wire than a 48 volt EV at 200 amps. 3% is almost 3 volts in the first
> case but not quite 1.5 volts in the second.
I don't think this is quite what it means. The size of the cable will
depend on the amount of current it can carry without overheating (which
is independent of the cable length), and also on the amount of voltage
drop the particular application can tolerate (which is a function of
wire size and length).
If the application requires wire that can carry 200A continuously, then
this sets the minimum wire size you can use. The amount of voltage drop
you can tolerate will determine if you need to use an even larger wire
since the length of wire required is the same regardless of its size.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
hey guys the 1st problem they had on the BUILDING was that the load was 18
amps which was too large for #12 wire the bldg code is 80% of 20 amps nec art.
310-16 and tables and notes
#12 wire foe voltage drop calculating starts @ 25 amps for thhn wire however
the notes to the table specifically say that #12 wire will be protected by a
20 amp circuit breaker which can only have a load of 16 amps max. per nec
art. 240 . do not confuse the ac systems in a building with the dc systems on
a ev . second the vd of a branch circuit starts at the voltage at the line
side of the panel and then is read at the end of the DEVICE that the load is
connected to not at the voltage applied to the load .
HERE IS THE IMPORTANT PART OF THIS EMAIL
the building wiring is the apple and the ev wiring is an orange they are
both fruit but not comparable
----- Original Message -----
From: Roger Stockton<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Thursday, February 08, 2007 6:32 PM
Subject: RE: wiring size
Paul G. wrote:
> I thought he was suggesting that the *acceptable* voltage drop is
> usually considered as a percentage of the applied voltage.
I think you are correct. I had to search waaay back to find (what I
think to be) Roland's original statement:
>> >> > A 1/0 copper stranded wire that has a insulation rating of 90
>> >> > degrees C or 194 degrees F is good for 170 amps continuous
>> >> > with a 3 percent voltage drop.
I think that this sort of statement is usually intended to mean that the
cable can carry the specified current at the specified temperature, and
the maximum *length* of the cable will be limited by the maximum
tolerable voltage drop (specified as a % of the applied voltage, i.e. as
a % drop).
I don't think there is an accepted value for voltage drop in our EV
wiring, but we tend to use welding cable for our traction wiring and so
manufacturer's charts specifying its ampacity often show maximum run
lengths vs current based on accepted values of voltage drop for welding
applications.
> If 3% is taken as an acceptable number (I'm not sure exactly what is
> acceptable) then a 96 volt EV running at 200 amps can use smaller
> wire than a 48 volt EV at 200 amps. 3% is almost 3 volts in the first
> case but not quite 1.5 volts in the second.
I don't think this is quite what it means. The size of the cable will
depend on the amount of current it can carry without overheating (which
is independent of the cable length), and also on the amount of voltage
drop the particular application can tolerate (which is a function of
wire size and length).
If the application requires wire that can carry 200A continuously, then
this sets the minimum wire size you can use. The amount of voltage drop
you can tolerate will determine if you need to use an even larger wire
since the length of wire required is the same regardless of its size.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Exactly what I was saying, the voltage drop in the cable depends on the
cable's resistance and the current.
How much voltage we are using to supply that current makes no difference
to the voltage drop.
> Also Here is your 2/0 cable theory.
> According to NEC 2005 Table 8 Conductor Properties
> 2/0 Coated wire offers a resistance of .0101 Ohms per 1000FT. Resistance
> is
> a constant! Therefore voltage and amperage will change. According to
> Ohm's
> law!
>
> Go to this site to figure your voltage drop.
> http://www.csgnetwork.com/voltagedropcalc.html
>
> -Rick
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Peter VanDerWal
> Sent: Thursday, February 08, 2007 4:05 PM
> To: [email protected]
> Subject: Re: wiring size
>
> Roland, the point you keep missing is that the total VOLTAGE has no effect
> on the voltage drop in the wires.
> Its ohms's law plain and simple. The voltage drop in the wire is equal to
> the wire's resistance * the current. The applied voltage is irelevent.
>
> Yes the size of the conductor affects the voltage drop, but the applied
> voltage does NOT. You would have the exact same voltage drop on a 240V
> ciruit running 18 amps with the same size conductor.
> Every electician knows this.
>
> The problem is that you were originally saying that voltage drop is a
> percentage of applied voltage, and it's not. It has NOTHING to do with
> applied voltage. Then you gave an example of battery sag to support your
> position, and this also has NOTHING to do with voltage drop in the wiring.
>
> Voltage drop depends on wire resitance, and in this case, connection
> resistance, and the current. That's it.
> Wire resistance depends on length and diameter. Connection resistance is
> normally negligible (unless it's a bad connection) but in EVs we tend to
> have a LOT of connections, so it adds up.
>
> To reiterate my point (which has not changed) voltage drop in wiring has
> NOTHING to do with applied voltage, it depends solely on the resistance
> and the current.
>
>> We change out a feeder on a building that had 50 feet of No. Awg 6 wire
>> from
>> the transformer, which was connected to about 100 feet of No. Awg. 10 to
>> a
>> power outlet. They had a 250 feet of No.12 AWG multi stranded copper
>> wire
>> plug into this power out that ran to a 18 amp load. They could not
>> understand why the voltage only read 90 volts!
>>
>> There was too much voltage drop for the size of the conductors running
>> 300
>> feet for that load. We replace the largest ones we can get in the
>> existing
>> conduit, so the voltage drop was now to about 115 volt.
>>
>> Therefore the size of conductor made a difference at the same load of 18
>> amps at the same voltage.
>>
>> If you apply the same voltage and ampere to different size conductors,
>> the
>> smaller conductor will have more voltage drop. Every electrical work
>> knows
>> this.
>>
>> I think the problem we have, is that you said, changing the ampere and
>> distance at the same voltage results in a voltage drop which is true,
>> while
>> I say the ampere and distance is constant, but a reducing the wire size
>> increases the voltage drop which is also true.
>>
>> As electrical workers, we install many different length of conductors on
>> a
>> 20 amp circuit. So we mainly think of the length of the circuit for
>> that
>> size wire. The preferred maximum run length of a No. 12 wire is 50
>> feet.
>> At and after 50 feet we use a No. 10 wire on a 20 amp circuit, even
>> though
>> the No. 10 wire is rated for 30 amps. A No. 8 wire is run for a maximum
>> of
>> 40 feet for a 40 amp circuit and so on.
>>
>> Roland
>>
>>
>>
>>
>>
>> ----- Original Message -----
>> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>> To: <[email protected]>
>> Sent: Thursday, February 08, 2007 8:59 AM
>> Subject: Re: wiring size
>>
>>
>>> <shakes head>
>>> Roland, at 200 amps a 2/0 cable drops about 0.5V regardless of pack
>>> voltage. You'll see the same voltage drop at 120V or 240V when
>>> carrying
>>> 200 amps.
>>>
>>> Of course the cable size has NOTHING to do with battery sag which is
>>> what
>>> you are describing.
>>> Battery sag is related to the batteries and has nothing to do with what
>>> size cables you use or how many connections there are, all that matters
>>> is
>>> how much current you pull, the particulars of your battery (some
>>> batteries
>>> sag less than others), and how well charged it is.
>>>
>>> > I said the total run of 50 feet circuit length, which includes the
>>> 2/0
>>> > cables, cable lugs, batteries, battery links, contactors, shunts and
>>> > controller. In my EV this is about 3 percent voltage drop in a EV 50
>>> > foot
>>> > circuit which includes the battery links.
>>> >
>>> > I am running 50 feet of circuit length of which the voltage reads 192
>>> > volts
>>> > at no load, and at exactly 200 amp load, my battery voltage reads
>>> about
>>> > 186
>>> > volts which is about 3 percent volt drop of the applied voltage. I
>>> read
>>> > this ampere and voltage with four industrial meters and also the
>>> > E-meter,
>>> > and they read all the same.
>>> >
>>> > Roland
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > ----- Original Message -----
>>> > From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>>> > To: <[email protected]>
>>> > Sent: Wednesday, February 07, 2007 11:26 PM
>>> > Subject: Re: wiring size
>>> >
>>> >
>>> >> I think something is wrong with your math.
>>> >>
>>> >> The voltage drop should be constant at a give current and length,
>>> not
>>> a
>>> >> percentage of applied voltage.
>>> >>
>>> >> 1/0 cable has about 0.096 ohms resistance per thousand feet, or
>>> 0.0048
>>> >> ohms for 50 feet. By my calculations, that works out to ~0.8 volts
>>> at
>>> >> 170
>>> >> amps and ~0.9 V at 195 amps.
>>> >>
>>> >> I don't have a clue how you came up with 10 volts of drop at 195
>>> amps,
>>> >> but
>>> >> that would make a nice space heater (almost 2,000 watts) ;-)
>>> >>
>>> >> > Hello Tim,
>>> >> >
>>> >> > The amperage rating of the conductor depends on many factors. The
>>> >> type
>>> >> > of
>>> >> > conductor, temperature rating of the insulation, running it in a
>>> >> > close
>>> >> > compartment and the circuit length.
>>> >> >
>>> >> > The circuit length is the total circuit loop length, not just the
>>> >> length
>>> >> > of
>>> >> > run between two points. In my EV, I have a total run of 25 feet
>>> of
>>> >> > conductor including all the battery lines, to the controller and
>>> to
>>> >> the
>>> >> > motor. The circuit length is 50 feet.
>>> >> >
>>> >> > 1/0 copper stranded bare wire run in air is good for 175 amps
>>> >> continuous
>>> >> > for
>>> >> > a 3 percent voltage drop.
>>> >> >
>>> >> > A 1/0 copper stranded wire that has a insulation rating of 90
>>> degrees
>>> >> C
>>> >> > or
>>> >> > 194 degrees F is good for 170 amps continuous with a 3 percent
>>> >> > voltage
>>> >> > drop.
>>> >> >
>>> >> > A 2/0 copper stranded wire with a insulation rating of 90 degrees
>>> C
>>> >> > is
>>> >> > good
>>> >> > for 195 amps continuous at 3 percent VD.
>>> >> >
>>> >> > The above distances are at 100 feet circuit length, so the voltage
>>> >> drop
>>> >> > will
>>> >> > be proportional to the length. At 50 feet circuit length it will
>>> be
>>> >> > about
>>> >> > 1.5 percent voltage drop.
>>> >> >
>>> >> > At 72 volts, it will drop to about 62 volts under a 195 amp load
>>> for
>>> >> > a
>>> >> > 50
>>> >> > foot circuit length. As you increase the ampere, the voltage
>>> will
>>> >> drop
>>> >> > proportional.
>>> >> >
>>> >> > It would be best to use 2/0 multi strand copper wire with a
>>> voltage
>>> >> > rating
>>> >> > of 300 volts for any voltages under 250 volts and 600 volt rating
>>> for
>>> >> > voltages over 300 volts.
>>> >> >
>>> >> > Roland
>>> >> >
>>> >> >
>>> >> >
>>> >> >
>>> >> > ----- Original Message -----
>>> >> > From: "Tim Gamber" <[EMAIL PROTECTED]>
>>> >> > To: <[email protected]>
>>> >> > Sent: Wednesday, February 07, 2007 8:32 PM
>>> >> > Subject: wiring size
>>> >> >
>>> >> >
>>> >> >> is 1/0 wiring big enough to take 450 amps for short bursts and
>>> >> 100-200
>>> >> >> amps
>>> >> >> continuous at 72 volts?
>>> >> >>
>>> >> >> _________________________________________________________________
>>> >> >>
> http://local.live.com/default.aspx?v=2&cp=43.658648~-79.383962&style=r&lvl=1
> 5&tilt=-90&dir=0&alt=-1000&scene=3702663&cid=7ABE80D1746919B4!1329
>>> >> >> >From January 26 to February 8, 2007
>>> >> >>
>>> >> >>
>>> >> >
>>> >> >
>>> >>
>>> >>
>>> >> --
>>> >> If you send email to me, or the EVDL, that has > 4 lines of
>>> legalistic
>>> >> junk at the end; then you are specifically authorizing me to do
>>> >> whatever
>>> >> I
>>> >> wish with the message. By posting the message you agree that your
>>> long
>>> >> legalistic signature is void.
>>> >>
>>> >>
>>> >
>>> >
>>>
>>>
>>> --
>>> If you send email to me, or the EVDL, that has > 4 lines of legalistic
>>> junk at the end; then you are specifically authorizing me to do
>>> whatever
>>> I
>>> wish with the message. By posting the message you agree that your long
>>> legalistic signature is void.
>>>
>>>
>>
>>
>
>
> --
> If you send email to me, or the EVDL, that has > 4 lines of legalistic
> junk at the end; then you are specifically authorizing me to do whatever I
> wish with the message. By posting the message you agree that your long
> legalistic signature is void.
>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
there is a company called Buss Fuse they sell all types of fuses ac - dc
whatever you need . they can give you an authoritive answer they will need
to know type of material . thickness and wideth
----- Original Message -----
From: Tony Hwang<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Thursday, February 08, 2007 3:23 PM
Subject: Question about 20 gauge fusible link, what is the blow current in
amps?
Hi all,
I have a question about 20 gauge fusible links. Can't find much information
about them,
and not many places to buy them by googling! Anyways, what is the current
that will
trip the fusible link in amps, for say, a 20 gauge fusible link? I'm guessing
15 amps or so?
- Tony
--- End Message ---
--- Begin Message ---
???So?
This has nothing to do with the original discussion and nothing to do with
EVs.
In an EV your pack voltage is what it is. I don't think anyone has ever
decided to make their pack voltage higher because of a 0.5V drop in the
cable.
The voltage drop in the typical EV is so small that the cable size is
irellevent. What makes a difference is whether or not it can handle the
current without over heating.
If the cable is big enough to handle the current, increasing it's size
only makes a tiny difference in the voltage drop.
Again this changes nothing, the voltage drop is not related to our pack
voltage, only the current.
> Peter,
>
> The voltage drop is what it means. It a drop of voltage of the source
> voltage measure on that circuit.
>
> If I have a 90 volts at the load end, and its 120 volts at the
> transformer.
> Is this not a 30 volt drop from the reference voltage of 120 volts.
>
> If Its reads 210 volts at the load end, and its 240 volts at the
> transformer, this is also a 30 volt drop.
>
> I know its VD = ohms x amps. But I am talking about the actual voltage at
> the end of a circuit. If this voltage is too low to operated a motor or
> other load, than you have to either increase the voltage or increase the
> conductor size which decreases the resistance and voltage drop
>
> We have to know what the voltage is to increase it a certain amount of
> percentage to bring up the line voltage under load.
>
> If we have a building that has 240 volt transformers feeding it. And the
> voltage at the end of circuit reads 230 volts, (a 10 volt drop), we
> normally
> tap up the transformers one 5 percent tap to about 250 volts no load, so
> we
> can have 240 volts on the service.
>
> We do not change any service entrances at this time, even though there is
> a
> 10 volt lost by the increase ampere or small conductors.
>
> Roland
>
>
>
>
>
>
>
>
> ----- Original Message -----
> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Thursday, February 08, 2007 3:05 PM
> Subject: Re: wiring size
>
>
>> Roland, the point you keep missing is that the total VOLTAGE has no
>> effect
>> on the voltage drop in the wires.
>> Its ohms's law plain and simple. The voltage drop in the wire is equal
>> to
>> the wire's resistance * the current. The applied voltage is irelevent.
>>
>> Yes the size of the conductor affects the voltage drop, but the applied
>> voltage does NOT. You would have the exact same voltage drop on a 240V
>> ciruit running 18 amps with the same size conductor.
>> Every electician knows this.
>>
>> The problem is that you were originally saying that voltage drop is a
>> percentage of applied voltage, and it's not. It has NOTHING to do with
>> applied voltage. Then you gave an example of battery sag to support your
>> position, and this also has NOTHING to do with voltage drop in the
>> wiring.
>>
>> Voltage drop depends on wire resitance, and in this case, connection
>> resistance, and the current. That's it.
>> Wire resistance depends on length and diameter. Connection resistance is
>> normally negligible (unless it's a bad connection) but in EVs we tend to
>> have a LOT of connections, so it adds up.
>>
>> To reiterate my point (which has not changed) voltage drop in wiring has
>> NOTHING to do with applied voltage, it depends solely on the resistance
>> and the current.
>>
>> > We change out a feeder on a building that had 50 feet of No. Awg 6
>> wire
>> > from
>> > the transformer, which was connected to about 100 feet of No. Awg. 10
>> to
>> > a
>> > power outlet. They had a 250 feet of No.12 AWG multi stranded copper
>> > wire
>> > plug into this power out that ran to a 18 amp load. They could not
>> > understand why the voltage only read 90 volts!
>> >
>> > There was too much voltage drop for the size of the conductors running
>> > 300
>> > feet for that load. We replace the largest ones we can get in the
>> > existing
>> > conduit, so the voltage drop was now to about 115 volt.
>> >
>> > Therefore the size of conductor made a difference at the same load of
>> 18
>> > amps at the same voltage.
>> >
>> > If you apply the same voltage and ampere to different size conductors,
>> > the
>> > smaller conductor will have more voltage drop. Every electrical work
>> > knows
>> > this.
>> >
>> > I think the problem we have, is that you said, changing the ampere and
>> > distance at the same voltage results in a voltage drop which is true,
>> > while
>> > I say the ampere and distance is constant, but a reducing the wire
>> size
>> > increases the voltage drop which is also true.
>> >
>> > As electrical workers, we install many different length of conductors
>> on
>> > a
>> > 20 amp circuit. So we mainly think of the length of the circuit for
>> > that
>> > size wire. The preferred maximum run length of a No. 12 wire is 50
>> > feet.
>> > At and after 50 feet we use a No. 10 wire on a 20 amp circuit, even
>> > though
>> > the No. 10 wire is rated for 30 amps. A No. 8 wire is run for a
>> maximum
>> > of
>> > 40 feet for a 40 amp circuit and so on.
>> >
>> > Roland
>> >
>> >
>> >
>> >
>> >
>> > ----- Original Message -----
>> > From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>> > To: <[email protected]>
>> > Sent: Thursday, February 08, 2007 8:59 AM
>> > Subject: Re: wiring size
>> >
>> >
>> >> <shakes head>
>> >> Roland, at 200 amps a 2/0 cable drops about 0.5V regardless of pack
>> >> voltage. You'll see the same voltage drop at 120V or 240V when
>> >> carrying
>> >> 200 amps.
>> >>
>> >> Of course the cable size has NOTHING to do with battery sag which is
>> >> what
>> >> you are describing.
>> >> Battery sag is related to the batteries and has nothing to do with
>> what
>> >> size cables you use or how many connections there are, all that
>> matters
>> >> is
>> >> how much current you pull, the particulars of your battery (some
>> >> batteries
>> >> sag less than others), and how well charged it is.
>> >>
>> >> > I said the total run of 50 feet circuit length, which includes the
>> >> > 2/0
>> >> > cables, cable lugs, batteries, battery links, contactors, shunts
>> and
>> >> > controller. In my EV this is about 3 percent voltage drop in a EV
>> 50
>> >> > foot
>> >> > circuit which includes the battery links.
>> >> >
>> >> > I am running 50 feet of circuit length of which the voltage reads
>> 192
>> >> > volts
>> >> > at no load, and at exactly 200 amp load, my battery voltage reads
>> >> about
>> >> > 186
>> >> > volts which is about 3 percent volt drop of the applied voltage. I
>> >> read
>> >> > this ampere and voltage with four industrial meters and also the
>> >> > E-meter,
>> >> > and they read all the same.
>> >> >
>> >> > Roland
>> >> >
>> >> >
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > ----- Original Message -----
>> >> > From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>> >> > To: <[email protected]>
>> >> > Sent: Wednesday, February 07, 2007 11:26 PM
>> >> > Subject: Re: wiring size
>> >> >
>> >> >
>> >> >> I think something is wrong with your math.
>> >> >>
>> >> >> The voltage drop should be constant at a give current and length,
>> >> >> not
>> >> a
>> >> >> percentage of applied voltage.
>> >> >>
>> >> >> 1/0 cable has about 0.096 ohms resistance per thousand feet, or
>> >> 0.0048
>> >> >> ohms for 50 feet. By my calculations, that works out to ~0.8
>> volts
>> >> at
>> >> >> 170
>> >> >> amps and ~0.9 V at 195 amps.
>> >> >>
>> >> >> I don't have a clue how you came up with 10 volts of drop at 195
>> >> amps,
>> >> >> but
>> >> >> that would make a nice space heater (almost 2,000 watts) ;-)
>> >> >>
>> >> >> > Hello Tim,
>> >> >> >
>> >> >> > The amperage rating of the conductor depends on many factors.
>> The
>> >> >> type
>> >> >> > of
>> >> >> > conductor, temperature rating of the insulation, running it in a
>> >> >> > close
>> >> >> > compartment and the circuit length.
>> >> >> >
>> >> >> > The circuit length is the total circuit loop length, not just
>> the
>> >> >> length
>> >> >> > of
>> >> >> > run between two points. In my EV, I have a total run of 25 feet
>> >> >> > of
>> >> >> > conductor including all the battery lines, to the controller and
>> >> >> > to
>> >> >> the
>> >> >> > motor. The circuit length is 50 feet.
>> >> >> >
>> >> >> > 1/0 copper stranded bare wire run in air is good for 175 amps
>> >> >> continuous
>> >> >> > for
>> >> >> > a 3 percent voltage drop.
>> >> >> >
>> >> >> > A 1/0 copper stranded wire that has a insulation rating of 90
>> >> degrees
>> >> >> C
>> >> >> > or
>> >> >> > 194 degrees F is good for 170 amps continuous with a 3 percent
>> >> >> > voltage
>> >> >> > drop.
>> >> >> >
>> >> >> > A 2/0 copper stranded wire with a insulation rating of 90
>> degrees
>> >> >> > C
>> >> >> > is
>> >> >> > good
>> >> >> > for 195 amps continuous at 3 percent VD.
>> >> >> >
>> >> >> > The above distances are at 100 feet circuit length, so the
>> voltage
>> >> >> drop
>> >> >> > will
>> >> >> > be proportional to the length. At 50 feet circuit length it
>> will
>> >> be
>> >> >> > about
>> >> >> > 1.5 percent voltage drop.
>> >> >> >
>> >> >> > At 72 volts, it will drop to about 62 volts under a 195 amp load
>> >> for
>> >> >> > a
>> >> >> > 50
>> >> >> > foot circuit length. As you increase the ampere, the voltage
>> >> >> > will
>> >> >> drop
>> >> >> > proportional.
>> >> >> >
>> >> >> > It would be best to use 2/0 multi strand copper wire with a
>> >> >> > voltage
>> >> >> > rating
>> >> >> > of 300 volts for any voltages under 250 volts and 600 volt
>> rating
>> >> for
>> >> >> > voltages over 300 volts.
>> >> >> >
>> >> >> > Roland
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> > ----- Original Message -----
>> >> >> > From: "Tim Gamber" <[EMAIL PROTECTED]>
>> >> >> > To: <[email protected]>
>> >> >> > Sent: Wednesday, February 07, 2007 8:32 PM
>> >> >> > Subject: wiring size
>> >> >> >
>> >> >> >
>> >> >> >> is 1/0 wiring big enough to take 450 amps for short bursts and
>> >> >> 100-200
>> >> >> >> amps
>> >> >> >> continuous at 72 volts?
>> >> >> >>
>> >> >> >> _________________________________________________________________
>> >> >> >> http://local.live.com/default.aspx?v=2&cp=43.658648~-79.383962&style=r&lvl=15&tilt=-90&dir=0&alt=-1000&scene=3702663&cid=7ABE80D1746919B4!1329
>> >> >> >> >From January 26 to February 8, 2007
>> >> >> >>
>> >> >> >>
>> >> >> >
>> >> >> >
>> >> >>
>> >> >>
>> >> >> --
>> >> >> If you send email to me, or the EVDL, that has > 4 lines of
>> >> legalistic
>> >> >> junk at the end; then you are specifically authorizing me to do
>> >> >> whatever
>> >> >> I
>> >> >> wish with the message. By posting the message you agree that your
>> >> long
>> >> >> legalistic signature is void.
>> >> >>
>> >> >>
>> >> >
>> >> >
>> >>
>> >>
>> >> --
>> >> If you send email to me, or the EVDL, that has > 4 lines of
>> legalistic
>> >> junk at the end; then you are specifically authorizing me to do
>> >> whatever
>> >> I
>> >> wish with the message. By posting the message you agree that your
>> long
>> >> legalistic signature is void.
>> >>
>> >>
>> >
>> >
>>
>>
>> --
>> If you send email to me, or the EVDL, that has > 4 lines of legalistic
>> junk at the end; then you are specifically authorizing me to do whatever
>> I
>> wish with the message. By posting the message you agree that your long
>> legalistic signature is void.
>>
>>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
brundy is a good company . at honeywell we hace a solider tool that heats up
the connection I belive that the best way is to use a good crimp connector and
then solider the joint and finish with some heat srink cover . think about it
for a while .
----- Original Message -----
From: Lee Hart<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Thursday, February 08, 2007 7:47 AM
Subject: RE: RE
From: "Dewey, Jody
>What is the name of the crimper? A burdy? Where can those be found?
Burndy.
From: Jeff Shanab
> I got the burdy crimper because the dies close all the way then release,
> a preset amount every time.
Yes; that's why you get more consistent results. These crimpers have a
ratchet that lets you close the handles, but not open them again until you have
closed them the "right" amount.
Regarding the strength to operate them; mine have handles 2 feet long. That's
one heck of a lot of leverage. I don't think it takes more than 20-30 lbs on
the handles to crimp even 2/0. It's about twice this for 4/0, but I rarely need
anything this heavy.
If I'm doing a bunch of crimps, I usually put one handle in the bench vice,
so I only need to pull on the one free handle. This frees up the other hand to
hold the wire and terminal in position.
> I wanted the heatshrink to make a good seal around the connector and
> the 360 degree burndy die makes a smooth crimp.
I usually use the thick-walled heatshrink that has hot glue inside it. The
glue melts when you shrink it, forming a much better seal over irregular
surfaces.
--
Lee Hart
--- End Message ---
--- Begin Message ---
If we were talking about a short circuit yes, but we are talking about
into a load.
We were talking about keeping the current constant (in the orignal case
this was around 190 amps)
> Actually Chief, Voltage has every effect on voltage drop. Ohms law as you
> said also states that current will be divided by half when voltage is
> doubled. Hence a voltage drop of 3A at 150V will be 1.5A at 300V. WITH
> THE
> SAME WIRE!
> I am getting a little tired of the Egos that are on this list. Roland is
> every bit correct.
> -Richard Todd
> P.E. Electrical Engineering
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Peter VanDerWal
> Sent: Thursday, February 08, 2007 4:05 PM
> To: [email protected]
> Subject: Re: wiring size
>
> Roland, the point you keep missing is that the total VOLTAGE has no effect
> on the voltage drop in the wires.
> Its ohms's law plain and simple. The voltage drop in the wire is equal to
> the wire's resistance * the current. The applied voltage is irelevent.
>
> Yes the size of the conductor affects the voltage drop, but the applied
> voltage does NOT. You would have the exact same voltage drop on a 240V
> ciruit running 18 amps with the same size conductor.
> Every electician knows this.
>
> The problem is that you were originally saying that voltage drop is a
> percentage of applied voltage, and it's not. It has NOTHING to do with
> applied voltage. Then you gave an example of battery sag to support your
> position, and this also has NOTHING to do with voltage drop in the wiring.
>
> Voltage drop depends on wire resitance, and in this case, connection
> resistance, and the current. That's it.
> Wire resistance depends on length and diameter. Connection resistance is
> normally negligible (unless it's a bad connection) but in EVs we tend to
> have a LOT of connections, so it adds up.
>
> To reiterate my point (which has not changed) voltage drop in wiring has
> NOTHING to do with applied voltage, it depends solely on the resistance
> and the current.
>
>> We change out a feeder on a building that had 50 feet of No. Awg 6 wire
>> from
>> the transformer, which was connected to about 100 feet of No. Awg. 10 to
>> a
>> power outlet. They had a 250 feet of No.12 AWG multi stranded copper
>> wire
>> plug into this power out that ran to a 18 amp load. They could not
>> understand why the voltage only read 90 volts!
>>
>> There was too much voltage drop for the size of the conductors running
>> 300
>> feet for that load. We replace the largest ones we can get in the
>> existing
>> conduit, so the voltage drop was now to about 115 volt.
>>
>> Therefore the size of conductor made a difference at the same load of 18
>> amps at the same voltage.
>>
>> If you apply the same voltage and ampere to different size conductors,
>> the
>> smaller conductor will have more voltage drop. Every electrical work
>> knows
>> this.
>>
>> I think the problem we have, is that you said, changing the ampere and
>> distance at the same voltage results in a voltage drop which is true,
>> while
>> I say the ampere and distance is constant, but a reducing the wire size
>> increases the voltage drop which is also true.
>>
>> As electrical workers, we install many different length of conductors on
>> a
>> 20 amp circuit. So we mainly think of the length of the circuit for
>> that
>> size wire. The preferred maximum run length of a No. 12 wire is 50
>> feet.
>> At and after 50 feet we use a No. 10 wire on a 20 amp circuit, even
>> though
>> the No. 10 wire is rated for 30 amps. A No. 8 wire is run for a maximum
>> of
>> 40 feet for a 40 amp circuit and so on.
>>
>> Roland
>>
>>
>>
>>
>>
>> ----- Original Message -----
>> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>> To: <[email protected]>
>> Sent: Thursday, February 08, 2007 8:59 AM
>> Subject: Re: wiring size
>>
>>
>>> <shakes head>
>>> Roland, at 200 amps a 2/0 cable drops about 0.5V regardless of pack
>>> voltage. You'll see the same voltage drop at 120V or 240V when
>>> carrying
>>> 200 amps.
>>>
>>> Of course the cable size has NOTHING to do with battery sag which is
>>> what
>>> you are describing.
>>> Battery sag is related to the batteries and has nothing to do with what
>>> size cables you use or how many connections there are, all that matters
>>> is
>>> how much current you pull, the particulars of your battery (some
>>> batteries
>>> sag less than others), and how well charged it is.
>>>
>>> > I said the total run of 50 feet circuit length, which includes the
>>> 2/0
>>> > cables, cable lugs, batteries, battery links, contactors, shunts and
>>> > controller. In my EV this is about 3 percent voltage drop in a EV 50
>>> > foot
>>> > circuit which includes the battery links.
>>> >
>>> > I am running 50 feet of circuit length of which the voltage reads 192
>>> > volts
>>> > at no load, and at exactly 200 amp load, my battery voltage reads
>>> about
>>> > 186
>>> > volts which is about 3 percent volt drop of the applied voltage. I
>>> read
>>> > this ampere and voltage with four industrial meters and also the
>>> > E-meter,
>>> > and they read all the same.
>>> >
>>> > Roland
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > ----- Original Message -----
>>> > From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>>> > To: <[email protected]>
>>> > Sent: Wednesday, February 07, 2007 11:26 PM
>>> > Subject: Re: wiring size
>>> >
>>> >
>>> >> I think something is wrong with your math.
>>> >>
>>> >> The voltage drop should be constant at a give current and length,
>>> not
>>> a
>>> >> percentage of applied voltage.
>>> >>
>>> >> 1/0 cable has about 0.096 ohms resistance per thousand feet, or
>>> 0.0048
>>> >> ohms for 50 feet. By my calculations, that works out to ~0.8 volts
>>> at
>>> >> 170
>>> >> amps and ~0.9 V at 195 amps.
>>> >>
>>> >> I don't have a clue how you came up with 10 volts of drop at 195
>>> amps,
>>> >> but
>>> >> that would make a nice space heater (almost 2,000 watts) ;-)
>>> >>
>>> >> > Hello Tim,
>>> >> >
>>> >> > The amperage rating of the conductor depends on many factors. The
>>> >> type
>>> >> > of
>>> >> > conductor, temperature rating of the insulation, running it in a
>>> >> > close
>>> >> > compartment and the circuit length.
>>> >> >
>>> >> > The circuit length is the total circuit loop length, not just the
>>> >> length
>>> >> > of
>>> >> > run between two points. In my EV, I have a total run of 25 feet
>>> of
>>> >> > conductor including all the battery lines, to the controller and
>>> to
>>> >> the
>>> >> > motor. The circuit length is 50 feet.
>>> >> >
>>> >> > 1/0 copper stranded bare wire run in air is good for 175 amps
>>> >> continuous
>>> >> > for
>>> >> > a 3 percent voltage drop.
>>> >> >
>>> >> > A 1/0 copper stranded wire that has a insulation rating of 90
>>> degrees
>>> >> C
>>> >> > or
>>> >> > 194 degrees F is good for 170 amps continuous with a 3 percent
>>> >> > voltage
>>> >> > drop.
>>> >> >
>>> >> > A 2/0 copper stranded wire with a insulation rating of 90 degrees
>>> C
>>> >> > is
>>> >> > good
>>> >> > for 195 amps continuous at 3 percent VD.
>>> >> >
>>> >> > The above distances are at 100 feet circuit length, so the voltage
>>> >> drop
>>> >> > will
>>> >> > be proportional to the length. At 50 feet circuit length it will
>>> be
>>> >> > about
>>> >> > 1.5 percent voltage drop.
>>> >> >
>>> >> > At 72 volts, it will drop to about 62 volts under a 195 amp load
>>> for
>>> >> > a
>>> >> > 50
>>> >> > foot circuit length. As you increase the ampere, the voltage
>>> will
>>> >> drop
>>> >> > proportional.
>>> >> >
>>> >> > It would be best to use 2/0 multi strand copper wire with a
>>> voltage
>>> >> > rating
>>> >> > of 300 volts for any voltages under 250 volts and 600 volt rating
>>> for
>>> >> > voltages over 300 volts.
>>> >> >
>>> >> > Roland
>>> >> >
>>> >> >
>>> >> >
>>> >> >
>>> >> > ----- Original Message -----
>>> >> > From: "Tim Gamber" <[EMAIL PROTECTED]>
>>> >> > To: <[email protected]>
>>> >> > Sent: Wednesday, February 07, 2007 8:32 PM
>>> >> > Subject: wiring size
>>> >> >
>>> >> >
>>> >> >> is 1/0 wiring big enough to take 450 amps for short bursts and
>>> >> 100-200
>>> >> >> amps
>>> >> >> continuous at 72 volts?
>>> >> >>
>>> >> >> _________________________________________________________________
>>> >> >>
> http://local.live.com/default.aspx?v=2&cp=43.658648~-79.383962&style=r&lvl=1
> 5&tilt=-90&dir=0&alt=-1000&scene=3702663&cid=7ABE80D1746919B4!1329
>>> >> >> >From January 26 to February 8, 2007
>>> >> >>
>>> >> >>
>>> >> >
>>> >> >
>>> >>
>>> >>
>>> >> --
>>> >> If you send email to me, or the EVDL, that has > 4 lines of
>>> legalistic
>>> >> junk at the end; then you are specifically authorizing me to do
>>> >> whatever
>>> >> I
>>> >> wish with the message. By posting the message you agree that your
>>> long
>>> >> legalistic signature is void.
>>> >>
>>> >>
>>> >
>>> >
>>>
>>>
>>> --
>>> If you send email to me, or the EVDL, that has > 4 lines of legalistic
>>> junk at the end; then you are specifically authorizing me to do
>>> whatever
>>> I
>>> wish with the message. By posting the message you agree that your long
>>> legalistic signature is void.
>>>
>>>
>>
>>
>
>
> --
> If you send email to me, or the EVDL, that has > 4 lines of legalistic
> junk at the end; then you are specifically authorizing me to do whatever I
> wish with the message. By posting the message you agree that your long
> legalistic signature is void.
>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
On Thu, 8 Feb 2007 16:11:37 EST, you wrote:
>
>Question: Do I need regulators to even out the charge on each battery? If
>so, what brand/make to you recommend? Ang? Rudman? Others?
>
>THANK YOU VERY MUCH!
>
><http://www.austinev.org/evalbum/887>
>
>David in Georgia
>
What a cool conversion. I really like my PowerCheqs. For the price
you can't beat Lee's Zener regs.
R. Matt Milliron
1981 Jet Electrica
http://www.austinev.org/evalbum/702
My daughter named it, "Pikachu". It's yellow and black,
electric and contains Japanese parts, so I went with it.
--- End Message ---
--- Begin Message ---
On Feb 8, 2007, at 4:32 PM, Roger Stockton wrote:
I wrote earlier:
If 3% is taken as an acceptable number (I'm not sure exactly what is
acceptable) then a 96 volt EV running at 200 amps can use smaller
wire than a 48 volt EV at 200 amps. 3% is almost 3 volts in the first
case but not quite 1.5 volts in the second.
I don't think this is quite what it means. The size of the cable will
depend on the amount of current it can carry without overheating (which
is independent of the cable length), and also on the amount of voltage
drop the particular application can tolerate (which is a function of
wire size and length).
If the application requires wire that can carry 200A continuously, then
this sets the minimum wire size you can use. The amount of voltage
drop
you can tolerate will determine if you need to use an even larger wire
since the length of wire required is the same regardless of its size.
I think that is what I said. The misunderstanding may be because I was
thinking about the insulation too. What temperature rated insulation do
you want to buy? You can run more current than the generally accepted
maximum for a given wire size is you want to pay for higher temperature
rated insulation.
There are a number of answers to this equation. Bigger wire increases
an EVs weight. Smaller wire increases power losses. How the wire is
routed/suspended changes the heating it will experience. A good margin
of safety should be maintained. More information almost always gets
better answers :-)
Paul "neon" G.
--- End Message ---
--- Begin Message ---
Roland, I think I've figured out where you went wrong.
You said you saw your pack voltage sagged 3% (from 192V to 186V) under a
200 Amp load and apparently you mistakenly attributed this to voltage drop
in the wiring.
The vast amount of this voltage drop was in the batteries themselves due
to their internal resistance, and not in the wiring.
I suppose you could describe battery voltage sag as a percentage of pack
voltage, since it depends on how many cells you have (more cells in
series, more voltage sag). However, this would be somewhat meaningless as
battery voltage sag is dependent on the batteries internal resistance and
this varies constantly. It changes depending on how old the batteries
are, how warm/cold they are, and their SoC, specific gravity, etc.
Anyway, the voltage sag was mostly due to the batteries and not the wire.
This discussion of house wiring isn't really relevent and doesn't change
anything anyway.
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
I don't know about you, but 3% voltage drop is WAY more than I would find
acceptable.
Assuming a 120V pack, 3% voltage drop would represent a loss of almost
1500 watts at 400 amps. That's a lot of wasted heat.
> On Feb 8, 2007, at 2:05 PM, Peter VanDerWal wrote:
>
>> The problem is that you were originally saying that voltage drop is a
>> percentage of applied voltage, and it's not. It has NOTHING to do with
>> applied voltage. Then you gave an example of battery sag to support
>> your
>> position, and this also has NOTHING to do with voltage drop in the
>> wiring.
>
> I thought he was suggesting that the *acceptable* voltage drop is
> usually considered as a percentage of the applied voltage. If 3% is
> taken as an acceptable number (I'm not sure exactly what is acceptable)
> then a 96 volt EV running at 200 amps can use smaller wire than a 48
> volt EV at 200 amps. 3% is almost 3 volts in the first case but not
> quite 1.5 volts in the second.
>
> Paul "neon" G.
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Hmm, I think soldering is a bad idea.
If it's a good crimp connecting, then their is no where for the solder to
go, inside the lug. This means all you are doing is stiffening the cable
outside the lug and possibly creating a point where the strands will break
if there is any flex.
If you can't get a good crimp, then yeah go ahead and flow some solder in,
it will reduce the connection's resistance.
> brundy is a good company . at honeywell we hace a solider tool that
> heats up the connection I belive that the best way is to use a good crimp
> connector and then solider the joint and finish with some heat srink
> cover . think about it for a while .
> ----- Original Message -----
> From: Lee Hart<mailto:[EMAIL PROTECTED]>
> To: [email protected]<mailto:[email protected]>
> Sent: Thursday, February 08, 2007 7:47 AM
> Subject: RE: RE
>
>
> From: "Dewey, Jody
> >What is the name of the crimper? A burdy? Where can those be found?
>
> Burndy.
>
> From: Jeff Shanab
> > I got the burdy crimper because the dies close all the way then
> release,
> > a preset amount every time.
>
> Yes; that's why you get more consistent results. These crimpers have a
> ratchet that lets you close the handles, but not open them again until
> you have closed them the "right" amount.
>
> Regarding the strength to operate them; mine have handles 2 feet long.
> That's one heck of a lot of leverage. I don't think it takes more than
> 20-30 lbs on the handles to crimp even 2/0. It's about twice this for
> 4/0, but I rarely need anything this heavy.
>
> If I'm doing a bunch of crimps, I usually put one handle in the bench
> vice, so I only need to pull on the one free handle. This frees up the
> other hand to hold the wire and terminal in position.
>
> > I wanted the heatshrink to make a good seal around the connector and
> > the 360 degree burndy die makes a smooth crimp.
>
> I usually use the thick-walled heatshrink that has hot glue inside it.
> The glue melts when you shrink it, forming a much better seal over
> irregular surfaces.
> --
> Lee Hart
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
