UDC 621.316.35-422.42 : 62-472
: 621.316.584
.
DEUTSCHE NORM
I
Drilled holes
and screw connections for busbars
February 198
DIN
43 673
Rectangular cross section busbars
Part 1
Stromschienen-Bohrungen und -Verschraubungen; Stromschienen mit
Rechteck-Querschnitt
Supersedes July 1971 edition
As it is current practice in standards published b y the International Organization for Standardization (ISO), the
comma has been used throughout as a decimal marker.
There are no relevant regional or international standards in existence which cover the field of application of this
standard.
Dimensions in mm
1
Field of application and purpose
This standard applies t o rectangular cross section busbars, which are specified in DIN 43 670 and DIN 43 671 in
respect of constant current rating. This standard specifies the location and size of drilled holes in busbars and contains
basic data concerningthe design and construction of the screw connections.
If expansion joints in accordance with DIN 46 276 Part 1 to Part 3 are used, the drilled holes and screw connections
should in this case also be designed and constructed in accordance with DIN 43 673 Part 1.
Screw connections for busbars which form part of type tested installations do not come under the field of application
of this standard.
2
Dimensions, designation
Permissible deviations for spacings of hole centres:
0,3 mm
2.1 Drilled holes for busbars
Designationof a shape 1 drilled hole pattern for busbars of nominal width b = 12 mm and drilled hole diameter
= 5,5 mm:
d
Drilled hole pattern DIN 43 673 - 1 - 12 - 5,5
Table I .
--``````-`-`,,`,,`,`,,`---
'
12to50
Shape 1
I
Busbar widths
60
3
25 to 60
2
1
I
80 to 120
I
160to200
6
4
*$+a
-
i
1201
1601
2001
-
I
.-E l o o ]
I
- I
-
j -
i
-
i
-
i
I - I - I - I
I - I - I - 1
I
- I
- I
- I
-
-
i
-
i
-
I 2 0
140 I 5 0
1
- I - I20 140 I60 I
- I - j - I - 1 - 1 - I
- I - I - I - I - I - I
I
-
I -
I
-
I
40
40
- I - I
20
20
I
I
I
40
50
The shape designations 1 to 4 and 6 are in accordance with DIN 46 206 Part 2 "Flat connections".
z, For busbar widths of 120 mrn and over, one end of the busbar or the end of one stack of busbars shall be slotted
l)
Continued on pages 2 to 4
Sole sale rights of German Standards (DIN-Normen)are with Beuth Verlag GmbH. Berlin 30
Copyright Deutsches Institut Fur Normung E.V.
02.83
Provided by IHS under license with DIN
No reproduction or networking permitted without license from IHS
DIN 43 673 Part 1 Engl. Price group I
Sales No. O 1 0 5
Not for Resale
Page 2 DIN 43 673 Part 1
2.2 Screw connections for busbars (examples)
Table 2.
Longitudinal
connections
Eil
)
b b + ,
--``````-`-`,,`,,`,`,,`---
i
Numerical values of dimensions O , d , e,.and e2 as in table 1.
Oblong holes are permissible in one end of a busbar or in the end of a stack of busbars.
Indoors
Indoors and outdoors
Bolt
Property class
8.8 or higher,
in accordance with
DIN IS0 898 Part 1
8.8 or higher,
in accordance with
DIN I S 0 898 Part 1
Protection against
corrosion
A2G A4G (gai Znl
B2G,'B4G (gal Cd)
in accordancewith
DIN 267 Part CI
tZn (hot dip galvanized)
in accordance with
DIN 267 Part 10
Nut
Property class
8 or higher,
in accordance with
DIN I S 0 898 Part 2
8 or higher,
in accordance with
DIN IS0 898 Part 2
Protection against
corrosion
A2G, A4G (gal Zn)
B2G. B4G (gal Cd)
in accordancewith
D I N 267 Part 9
tZn (hot dip galvanized)
in accordance with
D I N 267 Part 10
in accordance with
DIN 6796.
protected against
corrosion
in accordance with DIN 6796 Part 2 (at present a t draft stage)
In the case of M 12 screw threads and of busbars made of
E-Alp or E-ALF 6,5 to E-ALF 10, it will be necessary to fit
additional washers. e.4. washer DIN 7349 - 13 St
Spring element
Conical spring
washer 3,
A2-70 or A4-70 in accordance
with DIN 267 Part 11
-
A2-70, A4-70, A2-80 or A4-80
in accordance with DIN 267 Part 11
-
~
Lubricant
Screw thread and head Oil or grease
seatins lubricated
M4
Recommended M 5
nominaI
M 6
tightening
torque
M8
N.m
M 10
for screw
M 12
M 16
3,
I
of MoS2 base (molybdenumdisulphide)
2
1.5
3
23
4.5
5,5
10
20
30
40
60
80
15
120
I
Other types of spring element which are capable of maintaining the necessary contact pressure may also be used.
I f necessary, additional washers must be provided.
Nominal tightening torques for non-lubricatedfasteners have not been specified, on account of the wide scatter of
friction values.
Copyright Deutsches Institut Fur Normung E.V.
Provided by IHS under license with DIN
No reproduction or networking permitted without license from IHS
Not for Resale
DIN 43 673 Part 1 Page 3
4
Screw connections for busbars in accordance with
DIN 43 670 and DIN 43 671
Washer,
e. g. in accordance
with DIN 7349
Bolt (a hexagon
bolt in accordance
with DIN 933 is
illustrated here)
Copper busbar bolted
on to copper busbar
Copper busbar bolted
Gripping
length
onto aluminium busba
A luminium busbar
bolted onto
aluminium busbar
i/
spring element
(a hexagon
in accordance
with DIN 934 is
illustrated here)
minium busbar
Il
Spring element
Standards referred to
DIN
DIN
DIN
DIN
DIN
DIN
DIN
267Part9
267 Part 10
267 Part 11
933
934
6796
6796 Part 2
DIN 7349
DIN 43 670
DIN 43 671
DIN 46 276 Part 1
DIN 46 276 Part 2
DIN 46 276 Part 3
DIN I S 0 898 Part 1
DIN IS0 898 Part 2
Mechanical fasteners; technical conditions of delivery; components with electroplated coatings
Mechanical fasteners; technical conditions of delivery; hot dip galvanized parts
Mechanical fasteners; technical conditions of delivery; with addenda to I S 0 3506, components of
stainless and acid resistant steels
Hexagon screws; thread approximately t o head; metric thread, types m and mg
Hexagon nuts; metric thread, metric fine thread; types m and mg
Conical spring washers for screw connections
( a t present a t draft stage) Conical spring washers for screw connections; conical spring washers of
stainless steel
Plain washers for bolts with heavy clamping sleeves
Aluminium busbars; dimensioning for constant current
Copper busbars; d-imensioning for constant current
Switchgear; expansion joints for busbars and flat connections; laminated - flexible
Switchgear; expansion joints for busbars and flat connections; laminated -highly flexible
Switchgear; expansion joints for busbars and flat connections; braided - highly flexible
Mechanical properties of fasteners; bolts, screws and studs
Mechanical properties of fasteners; nuts with specified proof load values
Further standards and documents
DIN 43 673 Part 2
Drilled holes and screw connections for busbars; busbars with channel cross section
DIN 46 206 Part 2
Connectionsfor electrical appliances; flat connectors 2 40A: principal dimensions and correlation
Dörfer, K.: Aktuelles über Stromschienenverschraubungen (New developments in screw connections for busbars), Elektrizitätswirtschaft 78 (1979),34-37
Previous editions
DIN 43 673: 12.55; DIN 43673 Part 1: 12.65,07.71
Amendments
For amendments made compared with the July 1971 edition, see Explanations.
Explanations
This standard has been drawn up by Subcommittee 433.1 "Busbars" of Deutsche Elektrotechnische Kommission im DIN
und VDE (DKE) (German ElectrotechnicalCommissionof DIN and VDE) DIN 43 673 Part 1 contains specifications
relating t o the location and size of drilled holes for busbars and basic data relating to the design and construction of the
screw connections. The connections for electrical appliances, f l a t connectors 40A t o 10000A, are featured in DIN 46 206
Part 2.
The difference in comparison with the July 1971 edition resides in a differentiated listing of the torques. Tests have
demonstratedthat the coefficients of friction originally assumed are inadequate in practice. In addition, the bolts with
property classes of less than 8.8 have been dropped from clause 3. In lieu thereof, the minimum contact force a t the
maximum coefficient of friction and at 0,9 times the nominal tightening torque (scatter) have been incorporated, as
these are required for switchgear in accordance with older standards.
The screw connections which comprise only one bolt presuppose that the busbars are adequately supported, so as t o
prevent with absolute certainty any slackening of such screw connections.
--``````-`-`,,`,,`,`,,`---
Copyright Deutsches Institut Fur Normung E.V.
Provided by IHS under license with DIN
No reproduction or networking permitted without license from IHS
Not for Resale
Page 4 DIN 43 673 Part 1
Indoors
Bolt, nut, surface
Lubricant
I
Overall coefficient of friction
from
to
CIGeS
Screw thread
1
M4
Gripping length
mm
4to 8
4 t o 12
4 t o 18
Indoors and outdoors
tZn
Oil or grease
of MoS2-base
(molybdenum d ¡sulphide)
0,05
0,12
I
I
1
gal Zn, gal Cd
0,105
0,15
A2-70, A4-70
0.13
0,21
Minimum contact force attained when applying a nominal
tiahtenina
toraue in accordance with table 3
"
"
.
I
1.55
2.15
3.20
kN
1,40
1,55
2,60
3,95
M8
M 10
M 12
4 to 60
6 t o 60
10 to 120
4.15
6.15
12.6
15,l
M 16
10 to 120
20.1
19,3
--``````-`-`,,`,,`,`,,`---
5,30
Copyright Deutsches Institut Fur Normung E.V.
Provided by IHS under license with DIN
No reproduction or networking permitted without license from IHS
Not for Resale