Kistler-Morse KM Microcell Bolt-On - Manual (Page 26)

8. To complete installation, ensure that both
screws are tightened until the T-handle driver
flexes in torsion, ¼ turn past the point where
the screw stops turning, with this flexing
procedure repeated several times to ensure the
screw is tight, and the voltage is in the range
-100mV to +100mV.
9. Repeat Steps 2 through 8 to install
Microcell™ B on the other side fo the web.
10. Prior to installing the environmental cover,
ensure the mating surface on the web is free
of dirt and grease. Reclean if necessary, being
careful not to remove the rust inhibitor on the
bare metal.
11. See Figure 4-8. Apply a generous bead of
sealant to the inside flange of the
environmental cover. Add extra sealant to the
cable exit channel.
A. Align the environmental cover over the
installed Microcell™ A, with the cable
through the cover’s exit channel.
B. Press the cover against the web, squeezing
out the sealant around the edges. Be
careful not to squeeze too much sealant
out.
C. Use your finger to smooth the sealant
around all edges and joints, eliminating
areas where moisture may pool, especially
along the top edge. Verify the sealant
forms a continuous, watertight seal. Ensure
the cable exit channel is completely sealed.
D. Repeat Step 11 for Microcell™ B.
CAUTION
Only use Sikaflex 1A polyurethane sealant or
Dow Corning RTV 738 or RTV 739. Other
sealants may contain acetic acid, which is
harmful to sensors and electronics.
Figure 4-8. Environmental Cover.
12.If you created any holes that go completely
through the web, spread sealant (Sikaflex 1A
polyrethane sealant or Dow Corning RTV738
or RTV 739) over the open holes. Use your
finger to press sealant into each hole.
MOUNTING JUNCTION BOX
MOUNTING LOCATION
Each junction box can be wired to a maximum of
two Microcell™ sets (four Microcells™ total):
1. One set of Microcells™ on a beam; both
Microcells™ are wired to one junction box.
2. Two sets of Microcells™ on a beam; all four
Microcells™ are wired to one junction box if
the sets are sufficiently close to each other to
allow the Microcell™ cables to reach the
junction box.
See Figures 4-9 and 4-19. Locate the junction
box on the instrumented beam or on the
supporting column or horizontal beam. Ensure
you have sufficient cable length and that a drip
loop will be formed by the Microcell™ cables when
wired to the junction box.
Figure 4-9. Junction Box Location - Two
Microcells™ Per Junction Box.
Figure 4-9. Junction Box Location - Four
Microcells™ Per Junction Box.
JUNCTION BOX INSTALLATION
CAUTION
Do not install junction boxes in the rain.
Moisture in the junction box will cause
corrosion and system errors.
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