OPERATION
BG 25 / 2011 /
2254_BG25_en_0000498763_V01
5 - 13
CAUTION
Shifting the torques is allowed only when the rotary drive isn’t in motion
and the drilling tool not in touch with the borehole bottom!
Condition to use the "high" torque mode for Kelly bars:
Only Kelly bars capable of transmitting the "High" torque of the rotary drive may be
used in the High torque mode. Know the max. permissible torque of your Kelly before
you begin or your Kelly could get damaged.
When the Kelly bars used are not designed for the torque of the rotary drive, the key-
operated switch (1) in the control cabinet must be turned to position of "High Torque
OFF" to prevent damage to the Kelly.
1
Limitation
Torque
High
Limitation
Torque
High
BK1206501.wmf
CAUTION
Risk of damaging the Kelly!
Operation with excessive torque can ruin the Kelly bar.
NOTE
With the key-operated switch (1) set to "OFF" in the control cabinet, the
1st gear of high torque is automatically blocked. And button (17) on the
control panel is out of function.
1
2
3
4
5
8
9
10
11
12
6
13
7
14
15
16
17
18
19
22
23
24
25
26
20
27
21
28
KDK
2
1
KDK
KDK
1
P
KDK
KDK
P
return flow
BK19025002.wmf