GE Industrial Solutions AKD-20 Low Voltage Switchgear - Manuel (Page 40)

AKD-20 Low Voltage Switchgear
Chapter 4. Equipment Installation
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Indoor Equipment.
1. ANCHORING BY ANCHOR BOLTS - Indoor equipment are
normally secured to their final mounting surface by anchor
bolts threaded into the embedded channel sills. The bolts
were loosely threaded into place before reassembling the
equipment shipping splits and connecting to the close-
coupled transformer, if appropriate.
The anchor bolts should now be tightened with a torque of 35-40 ft-
lbs.
2. ANCHORING BY WELD - An alternate method of anchoring the
equipment to its foundation is to weld the equipment to floor
sills (or the floor itself if constructed of steel). Several methods,
shown on Fig. 4-21, are available to the purchaser for welding
the equipment to the channel sills.
a. The front of the equipment is attached to the embedded
channel sills (1), Fig. 4-21, by two 3/16-inch fillet welds (2).
It is recommended that two welds, each 2-1/2 inches long
(min.), be used for each section to firmly tie the bottom
width post (3) to the channel sill.
b. The rear of the equipment may be anchored by one of
three procedures:
•
The first method is by plug welds (4), Fig. 4-21, using the anchor
bolt holes in the rear sill angle (5). The plug weld should receive
a minimum 1/2-inch bead around the entire circumference of
the anchor bolt hole.
•
A second method of securing the front and rear sill angles (5) to
the channel sill (1) is the use of two linear fillet welds (2) for
each section. It is recommended that each weld be 2-1/2
inches long (min.) with a 3/16-inch fillet (min.).
• A third method for anchoring the rear of the equipment is to
remove the rear sill angle (5) from the switchgear and weld the
rear bottom width post (6) to the channel sill (1). These welds (2)
should, like the front welds, have a 3/16-inch (min.) fillet and
each have a minimum length of 2-1/2 inches.
4-20. Indoor equipment anchoring