AD-1252 Thermal Dispersion Probe Airflow Measuring System Installation Instructions
7
Installing the Thermal Dispersion Probes with
Insertion Mounting
1.
Inspect the duct work and/or opening to ensure no
obstructions or irregularities interfere with
installation of the probes. See
for probe mounting locations. See
Figure 8 through Figure 11 for more information
about three types of probe mounting.
Note:
Ensure that adequate clearance exists at the
installation site to permit installation and removal of the
probes.
2.
Based on information from
, determine where you want to
mount the probes and mark the hole locations on
the outside of the duct or the plenum.
a.
Mark a 3 in. (76 mm) hole (round or square)
where you want to insert each probe.
b.
Mark a 2 in. (50 mm) hole on the opposite side
of the duct or plenum from the insertion hole.
c.
Double-check the hole locations before
proceeding to the next step.
3.
Cut 3 in. (76 mm) and 2 in. (50 mm) diameter holes
(one set of holes for each probe). For rectangular
ducts, if the duct requires three probes, then make
three 3 in. (76 mm) holes on one side and three
2 in. (50 mm) holes on the opposite side of the
duct/plenum.
4.
Use standoff brackets to mount probes onto the
face of a damper (see Figure 10). When possible,
install probes perpendicular to damper blades for
best results.
5.
Remove the mounting plates on the mounting stud
end of the probe. Keep the nuts and washers for
next step.
6.
Holding the multiplexer end of the probe (the end
with the black box on it), insert the mounting stud
end of each probe into the 3 in. (76 mm) holes until
the probe mounting stud extends through the 2 in.
(50 mm) holes in the opposite side of the duct.
7.
With the probes in place, go to the other side of the
duct/plenum, and install the mounting plates onto
the studs. With the stud centered in the 2 in. (50
mm) hole, place the mounting bracket over the
stud, followed by the nut and washer. Tighten the
nut and washer against the mounting plate. Do not
over tighten.
Note:
Do not place screws in the four corner holes
of the mounting plates in this step.
8.
Measuring from the top or bottom of the duct/
plenum, locate the center of each probe stud to the
dimension indicated in
Once the stud is centered on the proper location,
secure the mounting plate with four self-drilling
screws. Repeat this step for each probe in the
duct/plenum.
9.
Moving back to the opposite side of the duct/
plenum, measure from the top or bottom as in the
previous step to center the multiplexer box on the
right dimension. The multiplexer box should be the
same distance from the top of the duct/plenum as
the center of the mounting stud on the opposite
side (within 1/2 in. [12 mm]). Once the multiplexer
box has been positioned, secure the mounting
plate with four self-drilling screws.
Table 4: Cable Length Recommendations (Maximum)
Number of Probes
Feet of Cable
1
1
Up to 100 feet
2
Up to 50 feet for each probe
3
Up to 33 feet for each probe
4
Up to 25 feet for each probe
1.
Cable lengths do not have to be equal.
IMPORTANT:
When multiplexers are exposed to
the outdoor environment, you must use the National
Electrical Manufacturers' Association (NEMA)
Type 4 weathershield option. (See Figure 8.) Use
appropriate moisture resistant conduit and
connections. Use the two screws provided to secure
closed the NEMA 4 cover.
IMPORTANT:
Install the probes with the mounting
plates square and without twisting or bending.
