If an aluminum mast and base are
used and can not be directly
attached to the structural steel work, or are
anchored to a concrete roof, then they need
to be directly electrically bonded to the
closest structural steel work or conductive
structural point. Refer to page
20
.
Mast Couplings and Guying Points
The inline coupling is designed to fit
between upper portion of the aluminum
mast and lower portion of the FRP mast. It
provides three guying anchor points and a
downconductor exit point. The maximum
mast diameter that the inline coupling is
able to clamp onto is
70
mm (
2 ⅞ in.) OD.
On both U-bolt connectors and
in line couplers, the maximum
torque is
55
kg-cm (
45
in-lb.).
Figure
18
: Base and mounting dimensions
IMPORTANT
– To maintain the
necessary clearance between the
nVent ERICO Dynasphere air terminal and
the top of the mast, the FRP mast must
protrude at least
1400
mm above the top of
the structure. The following shows the
required positioning dimensions for the two
available FRP mast sizes.
2
meter FRP Mast
Overlap with structure =
600
mm (
24
in.)
Protrusion above structure =
1400
mm (
55
in.)
4
.
6
meter FRP Mast
Overlap with structure =
1
.
5
m (
59
in.)
Protrusion above structure =
3
.
1
m (
122
in.)