Shively Labs 6842, Instruction Manual Installation, Operation, & Maintenance

Page: 29 / 64

21
Installing the De-icer System (if applicable)
De-icer installation
Installing the de-icer
harness
a. Install the main de-icer harness with its bay junction boxes as shown in
Figure 13 on page 20 and Figure 14 on page 22. Connect the leads from each
bay’s de-icer pigtail to the main harness in that bay’s junction box as shown.
CAUTION
It is important to ground both the tower junction box and the control
box, as shown in the schematic diagrams.
b. Furnish a tower junction box as shown schematically in Figure 13 to connect
the antenna’s de-icer harness to the main power.
c. Using tie-wraps, secure the entire length of the de-icer harness to the RF
feedline at about 24" (60 cm) intervals. Run the ten-foot de-icer pigtail along
a feedline mount to the tower junction box and secure it to the mount and
the tower.
Installing the thermostat
(if applicable)
If you are using a thermostat, you may locate and mount it at your discretion.
We recommend mounting it as close as practical to the antenna.
CAUTION
Shively Labs's de-icer control box, Model 94068, is designed for interior
installation only.
CAUTION
When testing the thermostat, be sure to have one or both thermostat
leads disconnected before taking resistance readings. Otherwise, read-
ings may be affected by other components.
a. Before you connect the thermostat, measure the resistance across the
thermostat circuit and from it to ground to ensure that there are no short-
circuits. Thermostat readings should be as shown in Table 3 on page 23.
b. Mount the thermostat near the antenna and connect the thermostat leads to
points S1 and S2 in the control box as shown in the schematic diagram,
Figure 13 on page 20.
Table 2. De-icer specifications
Heater leg
resistance,

Heater leg (T1 or T2)
current draw, amps
1-Bay 72 1.7
2-Bay 36 3.4
3-Bay 24 5
4-Bay 18 6.7
5-Bay 14.4 8.3
6-Bay 12 10
8-Bay, single circuit 9 13.3