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Possible source for Dupla-type cables

Contents:

  1. re: substrate heating
    by "Wehde, Mark B." <MBW01-at-msmail2.mayo.edu> (Tue, 25 Apr 1995)
  2. That wire source
    by Erik Olson <(e-mail)> (Wed, 26 Apr 1995)
  3. Calculating diy ugh
    by dallenb-at-feldspar.com ()
  4. Cooner Wire
    by nitro-at-oeonline.com (Didi Soichin) (Mon, 4 Mar 96)

re: substrate heating

by "Wehde, Mark B." <MBW01-at-msmail2.mayo.edu>
Date: Tue, 25 Apr 1995

>No way.  Dupla charges $90-140 for their cables.  The one in my tank, a
>50-watter, makes about two full trips back and forth, making its length
>under 20 feet.  That's still half the price Dupla would charge.  The key
>is not being stronger than normal wire, the key is being more resistive!

>* Please please tell me the source for this! :) *

The company is:
     Cooner Wire
     9186 Independence
     Chatsworth, CA 91311
     818-882-8311

They sell wire they call Miniature Electrode Wire AS 155 Series which is 
stranded copper with a silicone rubber insulation.
Part #         Wire Gage ohms/foot
AS155-28  28        .066
AS155-29  29        .085
AS155-30  30        .108
AS155-31  31        .145
AS155-32  32        .170
AS155-33  33        .218
AS155-34  34        .272
AS155-36  36        .436
     
They also sell AS 180 Series wire which is stranded stainless steel with a 
silicone rubber insulation.
Part #         Wire Gage ohms/foot
AS180-28  28        2.8
AS180-29  29        3.57
AS180-30  30        4.56
AS180-31  31        6.13
AS180-32  32        7.18
AS180-33  33        9.19
AS180-34  34        11.48
AS180-36  36        18.38
AS180-38  38        30.63
AS180-40  40        45.94
     
They also sell wire they call Bioflex Insulated Wire.  It can have either 
clear non-hygroscopic fluorocarbon (FEP) or polyvinylchloride (PCV) 
insulation.  Wire sizes range from 28 - 40 gage with nominal resistance  of 
..066 to 1.08 ohms / foot for copper wire or 2.8 - 45.94 ohms / foot for 
stainless steel wire.  It is described as being ultra flexible and suitable 
for implantation in vivo.  It is multistranded.

I looked at using wire from this company and decided it was more money  than 
I  wanted to spend so I used standard stranded 26 gage copper wire in my 
tank.  I also ran two lengths of wire and brought all four ends out of the 
tank.  Now if one wire is broken I will attach my transformer to the other 
wire.  This seemed a good safety measure to prevent having to tear down a 
tank.

Mark

That wire source

by Erik Olson <(e-mail)>
Date: Wed, 26 Apr 1995/1996

I have created a little length chart given the resistances of the medical
electrode wires posted by Mark Wehde.  
Looks promising!

>From: "Wehde, Mark B." <MBW01-at-msmail2.mayo.edu>
>Subject: RE: Heating cable source

>The company is:
     Cooner Wire
     9186 Independence
     Chatsworth, CA 91311
     818-882-8311

>They sell wire they call Miniature Electrode Wire AS 155 Series which is 
>stranded copper with a silicone rubber insulation.
>...
>They also sell wire they call Bioflex Insulated Wire.  It can have either 
>clear non-hygroscopic fluorocarbon (FEP) or polyvinylchloride (PCV) 
>insulation.  Wire sizes range from 28 - 40 gage with nominal resistance  of 
>..066 to 1.08 ohms / foot for copper wire ...



                        24V     50W=30W=12W     100W=56W=25W    12V     12V
Part #  Gage ohms/ft    30W     24V 18V 12V     24V  18V 12V    30W     50W
                        1.3A    2A 1.7A 1A      4A  3.4A  2A    2.8A    4A

                        -----req'd cable length in feet----------------
AS155-32  32  .170                                              28      17
AS155-33  33  .218                              26              22      13
AS155-34  34  .272              42              21              17
AS155-36  36  .436      44      26              13              11
???       38       
???       40  1.08      18      11              5.3


(The steel wire has too high of a resistance; deleted)

Looks like the best bet for constructing 24-volt cables is 40-gauge (30W),
36-38 gauge (50W), and 34-gauge (100W), scaling appropriately down
for lower voltages.  My sister lives a few blocks away from this address,
so perhaps if they're not into shipping I might get her to go pick something
up personally for me.

   - Erik


Calculating diy ugh

by dallenb-at-feldspar.com

                  Underground heating cable
    

                power chart
    power = v*v/r   resistance = v*v/p
    watts  volt  v*v      Res    Amp
      25    6     36     1.440   4.167
      25   12    144     5.760   2.083
      25   24    576    23.040   1.042
    
      50    6     36     0.720   8.333
      50   12    144     2.880   4.167
      50   24    576    11.520   2.083
    
      75    6     36     0.480  12.500
      75   12    144     1.920   6.250
      75   24    576     7.680   3.125
    
     100    6     36     0.360  16.667
     100   12    144     1.440   8.333
     100   24    576     5.760   4.167
    

                               
                      length of cable require in meters
                      based on 1 to 2 watts per 10 litre of water
                  5      7      9     11     13     15     17     20
    
        Watts                Required resistance per meter
         25     0.288  0.206  0.160  0.131  0.111  0.096  0.085  0.072
         25     1.152  0.823  0.640  0.524  0.443  0.384  0.339  0.288
         25     4.608  3.291  2.560  2.095  1.772  1.536  1.355  1.152
    
         50     0.144  0.103  0.080  0.065  0.055  0.048  0.042  0.036
         50     0.576  0.411  0.320  0.262  0.222  0.192  0.169  0.144
         50     2.304  1.646  1.280  1.047  0.886  0.768  0.678  0.576
    
         75     0.096  0.069  0.053  0.044  0.037  0.032  0.028  0.024
         75     0.384  0.274  0.213  0.175  0.148  0.128  0.113  0.096
         75     1.536  1.097  0.853  0.698  0.591  0.512  0.452  0.384
    
         100    0.072  0.051  0.040  0.033  0.028  0.024  0.021  0.018
         100    0.288  0.206  0.160  0.131  0.111  0.096  0.085  0.072
         100    1.15   0.823  0.640  0.524  0.443  0.384   0.34  0.288
    

          wire size    
Gauge   Dia-mm  R/mtr   Res/1000'   
                               
 26     0.405    0.137    41.6
 27     0.361    0.172    52.5
 28     0.321    0.217    66.2
 29     0.286    0.274    83.4
 30     0.255    0.345   105.2
 31     0.227    0.436   132.7
 32     0.202    0.516   157.3
 33     0.180    0.693   211.0
 34     0.160    0.873   266.0

    
         Hammond Transformers as listed 1994 
       (available at most electrical suppliers)
 
 volts  2amps  3amps  4amps  5amps  6amps  8amps 10amps
 
  6.3   166L6         166N6         165Q6         165S6
        ($13)         ($17)         ($22)         ($29)
 
 12.6  166L12        166N12        166Q12 165R12 165S12
        ($16)         ($25)         ($30)  ($26)  ($37)
 
 25    166L25 165M25 165N24 165P25               165S25
       ($12)  ($25)  $(27)  ($36)                ($50)

These prices are in Canadian $ from Electrosonic catalog
they sould be used as a guide only. The gaps could be filled 
with other manufactures.


example.
tank 255 ltr                   length = 122cm
hight = 46cm                   width  = 44cm
gravel 10cm                    volume 122x36x44 = 193ltr
length of cable = 122x(44/6)+(50x2) = 10.9 metres.

Wattage required 192/10 = 19.3 at 1 watt/10ltr or 38.6 watts at 2w/10ltr

lower wattage(20):
under 11 mtr length of cable 2 options .131 or .524 ohms/mtr. I would choose
the highest voltage possible. 12 volts at .524 ohm/mtr at 2 amps, now look
at wire size available for .524; Nearest is .516 ohm/mtr and wire size of 32
gauge. Transformer is 166N12 rated at 4 amps.(actual 27.9 watts)

higher wattage(40):
11 metre length .262 ohms/mtr at 12 volts 4 amps. wire size .274 29 gauge
wire, transformer 166Q12 6 amps. (actual 52 watts)



Doug Bardell
Garson, Ont, Ca.

Cooner Wire

by nitro-at-oeonline.com (Didi Soichin)
Date: Mon, 4 Mar 96

 Well, I received today in the mail two samples of wire from Cooner
Wire. I read about them in the Krib/Plants/Tech series of articles on
DIY substrate heating so I gave them a call. The gentleman I've spoke
with was extremely helpful and sent me samples of the silicone rubber
coated and the PVC coated one, both in 36 gauge. Unfortunately they
are very, very thin (O.D. .0258, it doesn't say if that's inches or
mm). I was hoping they would be similar to the EKG hook-up wire that I
have at work, which is a thick 1/8" silicone coated. The Dupla ones
are 1/8" too so, until I setup the big tank, bye-bye substrate heating

:-(

 Didi Soichin
 nitro-at-oeonline.com
 Westland, MI, USA

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