Thread size
M6
M8
M10
M12
M16
M20
M30
M42
M48
Spanner size
10
13
17
19
24
30
46
65
75
A) Bushing insulators
Low voltage (LV) DIN 42530
1. Fixing of bushing terminal stud:
cork gasket
nbr gasket
2. Connection between nuts
3. Fixing of flag connector to
terminal stud (bolt and nut in
stainless steel)
4. Bolts to flag connector surface
High Voltage (HV) DIN 42531
1. Fixing of top of terminal stud
(terminal stud and nuts in brass)
2. Connection to terminal stud
(terminal stud and nuts in brass)
3. Fixing of base
(stud and nut in stainless steel)
cork gasket
nbr gasket
Plug-in bushing
cork gasket
nbr gasket
B) LV connecting busbar
I
nterconnection
(pin and nut in 8.8 steel)
C) Cover / frame
Bolt and nut in stainless steel
(pitch = 60mm) = cork
gasket (pitch = 90mm) = nbr gasket
D) Busbar bushings
Fixing on cover
Top piece onto bottom piece
5,4-6Nm
20-25Nm
20-25Nm
8-15Nm
25-35Nm
25-35Nm
10-20Nm
10-15Nm
10-20Nm
10-15Nm
45-60Nm
250A
10-15Nm
7-10Nm
15-20Nm
40-60Nm
40-60Nm
10-15Nm
15-20Nm
20-35Nm
15-25Nm
65-85Nm
40-60Nm
40-60Nm
100-150Nm
95-130Nm
630A
25-55Nm
17-37Nm
70-100Nm
1000A
65-150Nm
44-100Nm
250-350Nm
2000A
100-300Nm
67-200Nm
3150A
150-500Nm
100-334Nm
Table 1:
Torque values of connection of live conductors
• Be sure that the cable and busbar terminal connections are not loose. Loose connections may
cause extra temperature rise and voltage drop.
• All connections have to be done according to Table 1.
Ulusoy Distribution Transformers Maintenance, Operation, Installation and Instruction Manual
