19
De-Icer Installation (if applicable)
3
De-Icer Installation (if applicable)
De-icer description
The de-icer system consists of the heating elements in the bays, their branch
cables, and the main harness. The main harness consists of a bay junction box
for each antenna bay, interbay cables, and a "pigtail" of wires about 10 feet (3
meters) long which you will connect to the tower junction box you are to pro-
vide.
The de-icer system requires 220 VAC, 50 - 60 Hz., single-phase.
Table 2
shows
approximate heater leg resistances and current draw, respectively.
Your system may also include specially-ordered items, such as a ground-
mounted control box, a power cable extending up the tower, or a tower-
mounted thermostat.
The following will help in installation:
• Electrical schematic, overall:
Figure 11
on page 21.
• De-icer control box layout:
Figure 13
on page 23.
• De-icer electrical specifications:
Table 2
on page 24.
• Thermostat readings:
Table 3
on page 24 and
Table 4
on page 25.
CAUTION
Remember that conditions may be favorable for icing on the tower, even
if they are not on the ground.
Shively Labs deicers are designed to prevent ice from forming on antenna ele-
ments and are not designed to melt ice that has already formed. For this rea-
son, Shively Labs recommends that the system be installed with a tower-
mounted dual-setting thermostat assembly (Shively Labs Model 55522-G502)
and de-icer control box (Shively Labs Model 94068) that ensure the deicers
are operated in the temperature range ice is most likely to form.
Before beginning de-
icer installation
Remember!
It is YOUR responsibility to ensure that your installation meets all appli-
cable electrical codes.
We recommend that the installation be reviewed by a qualified electri-
cian before you apply power.
CAUTION
De-icer heating elements are installed in bays as pairs of series-con-
nected heaters. Each individual heater is designed to operate at 120V.
Under no circumstances should 240V be applied across one heater,
between either hot wire to neutral.
CAUTION
All parts of the de-icer system within about 20 feet (6 meters) of any
radiator must be shielded from RF energy, and the entire outdoor por-
tion of the system must be made waterproof.
CAUTION
Note that unless an exterior box has been ordered specially, a de-icer
control box purchased from Shively Labs is designed for interior installa-
tion only.
WARNING
Installation should be per-
formed only by personnel
experienced in RF sys-
tems, qualified in electri-
cal work, and familiar
with this equipment.
