The Dubuis Earth Bonding System

Your #1 Connection For All Of Your Interconnect Requirements


The Dubuis Earth Bonding System





































Milrail Inc.
1-888-Milrail (645-7245) Fax 514 697-4125

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Earth Bonding


Operation and Installation

Milrails DUBUIS Earth Bond system is the quickest, easiest and most cost effective solution for
maintaining and installing grounding connections on steel and sheet metal.

The earth bond consists of two precision machined components : a stainless steel conical dowell and a tin
plated copper bush. (Figures 1 & 2). These two components are factory fitted (Figure 3) for your
convenience.


Unlike conventional welded grounding studs, installation of the Earth Bond requires no surface
pretreatment, preparation or cleaning.

The Earth Bond is simply inserted into a pre-drilled hole and then expanded using a light weight hydraulic
pulling tool. Final connection of the terminal lug to the mated contact face of the Earth Bond is achieved
with a self locking nut torqued to a pre-determined load. (Figures 1-4)




Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding


Advantages of the Earth Bond Grounding Stud

♦ Safe – No heat, no sparks, no fire.

♦ Quick and easy installation – Under 3 minutes from start to finish

♦ No surface preparation – Simply drill a hole and insert the bond.

♦ Universal application – Uneven surfaces, deck plates, bulkheads, steel box sections, railings, blind holes
and areas of restricted access.

♦ One man, high speed operation – Say goodbye to welding crews and fire watches.

♦ Lightweight, hand-held installation tooling – Install ground studs in the most hard to reach and awkward
locations.

♦ Water proof and weather proof operations – Install or remove in all weather conditions.

♦ Reliable, consistent connections – Low resistance and maximum contact every time.

♦ Non-corroding stainless steel – Say goodbye to rusted-out studs.

♦ Easy removal – A punch or drill is all it takes.












Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding

Which Type Of Earth Bond Should I Use?

Bonds are selected by wall thickness (or depth of the blind hole) and the size of the grounding lug.

Milrail offers two system sizes, 6mm and 10mm. Both sizes include Earth Bonds for thick and thin walls as
well as their own size of hydraulic pulling tool. (Refer to Table 1, 2 & 3 for P/N selection)

In order to determine the suitable Earth Bond for your application please consult the following table:

Table 1
Plate material
Steel – Stainless steel
1.5-4 mm
2-4 mm
>4 mm
>4 mm
Plate Thickness
.059-.158
.078-.158
.158- unlimited
.158- unlimited
M6
M10
M6
M10
Stud Size
.236
.394
.236
.394
Part Number
80923
80924
80925
80926
∅11.5 mm
∅19 mm
∅8.5 mm
∅13.5mm
Drilling diameter
.457
.752
.339
.535
Hydraulic tool
PMT6
PMT10
PMT6
PMT10
Torque value
6 Nm
30 Nm
6 Nm
30 Nm


Table 2
Plate material
Aluminum
1.5-4 mm
2-4 mm
>4 mm
>4 mm
Plate Thickness
.059-.158
.078-.158
.158- unlimited
.158- unlimited
M6
M10
M6
M10
Stud Size
.236
.394
.236
.394
Part Number
80958
80959
80960
80961
∅11.5 mm
∅19 mm
∅10.5 mm
∅15 mm
Drilling diameter
.457
.752
.413
.591
Hydraulic tool
PMT6
PMT10
PMT6
PMT10
Torque value
6 Nm
30 Nm
6 Nm
30 Nm





Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding


Which Type Of Hydraulic Setting Tool Should I Use?

Table 3
Hydraulic tool
PMT6
PMT10
Stud size
M6
M10
Part Number
80915
80916
Handle color
Yellow
Blue
Specifications
Force
10 kN
25 kN
Stroke
8 mm
Weight
1.280 Kg
Length
185 mm
Safety valve
Audible click























Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding


Further to extensive testing the following test reports have been provided courtesy of GEC
ALSTHOM TRACTION LTD, Channel Way, Preston to demonstrate the performance of the
DUBUIS EARTH BONDING process.

Tests were conducted on the Earth Bonds part number 80910, M6 for steel plate 1.5-5.5 mm
and 80911, M10 for steel plat 6-10 mm.

The tests were carried out on two of each sample, to give confidence in the performance of
the self fixing bosses.

1. Anti-rotation test, samples of each size were inserted into 2mm Tenform steel sheet with the hole sizes
recommended by Dubuis punched in them and the nut tightened onto three flat washers until the
maximum torque for copper connections in our spec 660/039, which is 8.5 Newton’s for the 6mm stud
and 34.0 Newton’s for the 10mm stud without any rotational slip. We then continued to increase the
torque until the stud began to elongate, this point was 13N for the 6mm stud and 62N for the 10mm stud,
no rotational slip was evident.

2. Vibration tests, a sample of each stud was mounted in a right angle section of 2mm Tenform steel sheet
150mm x 100mm x 100mm with the stud approximately centered in the vertical face, two cables of the
maximum size for each fixing were fastened to the stud at 180 degrees to each other and parallel to the
base of the angle plate. These were then subject to a mV drop test at 50A before carrying out the
vibration test to R1A20: 1995 category 1, class B. (For results see table).

3. Low temperature test, the samples used in 2 above were subjected to a series of low temperature cycles
and tested before and after for resistance and relaxation. The assembly comprising of the earth stud
fitted with the same connection terminals, a flat washer, Triple Bellville washer and a Phillidas nut
tightened to the correct torque. Pass criteria being not less than 80% of original damping force retained.

4. Water ingress a barrier of plasticene was placed round the rear of the bosses and filled with clean water,
no permeation was detected after 6 hours.

5. High current Temperature tests, sample bosses ware mounted in angle plates as in 2 above and the
currents shown on the attached graphs were applied to the bosses through a single cable of the correct
size for the stud. Milli-Volt drop tests were performed before and after testing at high current and
temperatures plotted on the attached graphs, the torque was checked alter cooling and found to be 90%
of the original value. Values for mV drop, before and after the tests were as follows:








Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding



6mm: Test current 246A
=
1.2mV at 20°C
6mm: Test current 246A
=
0.89mV after 1st test and .69mV after 2nd test
10mm: Test current 400A
=
0.89mV
10mm: Test current 400A
=
after 1st test and 0.68mV and 0.64 after 2nd test

As can be seen from the reductions above, the heating has caused the tin plating to flow slightly thereby
actually improving the performance, the relaxation that took place is to be expected in such a severe test and
would be unlikely to happen in service. The use of triple Bellville washers or single heavy duty Bellville
washer for any connection of this type not only provides an additional safety margin of clamping force, but
also ensures a better spread of the clamping force over the contact area and should be regarded as integral to
the design/use of these devices.

As can be seen from the graphs on the back pages, we have also tested the standard welded on earth boss.

We have not carried out comprehensive climatic/environment tests on these devices, however
having regard to the materials used, e.g. tin plated copper and stainless steel A2-70 we do not envisage any
real problems with this.

Temperature cycling of earth bosses
As requested 20 temperature cycles were carried out on two earth bosses (6mm & 10mm). One temperature
cycle consisted of placing the earth bosses in the freezer at -40°C for two hours and then taken out left to
return to ambient for two hours. Operations were carried out before and after testing to determine the affects
of the temperature cycling. See below for the table of results.


Resistance
Resistance
Tightening torque
Tightening torque
Before testing
after testing
Before testing
After testing
6mm
0.70mΩ
0.23mΩ
8NM
6NM
10mm
0.20mΩ
0.21mΩ
34NM
32NM

No visible alterations to either boss was seen.

Equipment Used:
Torque wrench R4396
Freezer Serial N°26557
Fluke 77 R7243
Power Supply R3965






Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding

Vibration test of Earth Bosses

Two earth bosses (6mm & 10mm) were subjected to a vibration and shock test to R1A20: 1995 category 1,
class B. As the orientation of the busbar was unknown the levels carried were:

Vertical Transverse, and Longitudinal = 7.9m/s2 rms.

5 hours simulated life test in each direction.

Vertical, Transverse, and longitudinal = 50m/s2 30ms shocks.

3 positive and 3 negative simulated shunting shocks in each direction.

Before and after testing, the resistance of the boss to plate junction was measured using a 50A input current.

Resistance before testing
Resistance after testing
mΩ
mΩ
10mm
6mm
10mm
6mm
0.20
0.64
0.20
0.38

On completion of the testing no visible damage had occurred.

Instruments Used:
Fluke 77


R7242

Farnell power supply R3965
Accelerometer

R8921

Charge amplifiers
R1937
Random & Shock software
R8313

Climatic/Environmental Tests

To conclude the testing program Dubuis Tooling commissioned a corrosion test according to IEC 68-2-11
(BS 2011 Ka).

The enclosed test report details testing parameters together with initial and final resistance values for both
M6 and M10 earth bonds to steel plates thickness 1.5 through to 10mm.









Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding

Salt Spray Tests

Salt spray test parameters
Temperature:
+35c





Duration:

96hrs
pH:


6.5/7.2
Salt Solution:
5% by weight





Spray rate:

1ml/2ml hr.

Terminal resistance values
All results in milliohms

Earth bonding corrosion resistance tests
Termination resistance
Measure between A&B with direct current not exceeding 50mA. Open circuit voltage 20mV DC.
Readings were recorded every 24 hours over 4 days.

Plate Size Initial 1 Initial 2 15.10.97
Change
16.10.97
Change
17.10.97
Change
20.10.97
Change
Thread
mm
A/B
A/B
A/B
From Initial
A/B
From Initial
A/B
From Initial
A/B
From Initial
S i z e
Steel 1.5
2.36
2.36
2.36
0
2.36
0
2.35
-0.01
2.34
-0.02
M10
Steel 1.5
2.36
2.36
2.35
-0.01
2.38
0.02
2.34
-0.02
2.34
-0.02
M10
Steel 1.5
3.76
3.76
3.75
-0.01
3.74
-0.02
3.74
-0.02
3.73
-0.03
M6
Steel 1.5
3.63
3.63
3.67
0.04
3.61
-0.02
3.62
-0.01
3.6
-0.03
M6
Steel 2
2.36
2.36
2.36
0
2.34
-0.02
2.34
-0.02
2.35
-0.01
M10
Steel 2
2.36
2.36
2.36
0
2.34
-0.02
2.34
-0.02
2.35
-0.01
M10
Steel 2
3.7
3.7
3.69
-0.01
3.68
-0.02
3.69
-0.01
3.68
-0.02
M6
Steel 2
3.61
3.61
3.6
-0.01
3.59
-0.02
3.59
-0.02
3.59
-0.02
M6
Steel 4
2.51
2.51
2.49
-0.02
2.5
-0.01
2.5
-0.01
2.48
-0.03
M10
Steel 4
2.5
2.5
2.48
-0.02
2.5
0
2.49
-0.01
2.47
-0.03
M10
Steel 4
3.7
3.7
3.68
-0.02
3.68
-0.02
3.68
-0.02
3.66
-0.04
M6
Steel 4
3.84
3.84
3.82
-0.02
3.83
-0.01
3.82
-0.02
3.8
-0.04
M6
Steel 5
2.46
2.46
2.46
0
2.45
-0.01
2.45
-0.01
2.44
-0.02
M10
Steel 5
2.44
2.44
2.44
0
2.44
0
2.43
-0.01
2.43
-0.01
M10
Steel 5
3.82
3.82
3.81
-0.01
3.8
-0.02
3.8
-0.02
3.8
-0.02
M6
Steel 5
3.77
3.77
3.76
-0.01
3.76
-0.01
3.76
-0.01
3.74
-0.03
M6
Steel 8
2.19
2.19
2.2
0.01
2.18
-0.01
2.18
-0.01
2.18
-0.01
M10
Steel 8
2.15
2.15
2.14
-0.01
2.14
-0.01
2.14
-0.01
2.13
-0.02
M10
Steel 8
3.39
3.39
3.38
-0.01
3.37
-0.02
3.37
-0.02
3.36
-0.03
M6
Steel 8
3.44
3.44
3.43
-0.01
3.42
-0.02
3.42
-0.02
3.41
-0.03
M6
Steel 10
2.37
2.37
2.36
-0.01
2.37
0
2.36
-0.01
2.34
-0.03
M10
Steel 10
2.37
2.37
2.36
-0.01
2.35
-0.02
2.35
-0.02
2.34
-0.03
M10
Steel 10
3.61
3.61
3.59
-0.02
3.58
-0.03
3.59
-0.02
3.56
-0.05
M6
Steel 10
3.66
3.66
3.65
-0.01
3.64
-0.02
3.4
-0.26
3.64
-0.02
M6



Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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Earth Bonding















































Milrail Inc. 111 rue Gun, Pointe-Claire, Quebec, Canada, H9R 3X2
Toll free: 1-888-MIL-RAIL, 1-888-645-7245, Fax: (514) 697-4125

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