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LCD-8 24VAC OVERVIEW
general
PART NO.
24861
REV
A.0
INSTALLATION AND OPERATION MANUAL |
The Snow Switch® Model LCD–8 (Figure 1) is a configurable
aerial snow melting system controller which makes automatic
snow melting a cost-effective alterna- tive in even the smallest
applications. Heaters operate at temperatures below the
LCD-8’s configurable set point, 38°F (3.3°C) default, only when
required. The adjust- able hold-on period, 3 hours default,
continues heater operation after snow stops to ensure complete
melting. The LCD–8 controller includes an internal magnetic
reed switch used for manual heater cycling and configuring the
controller’s operational temperature set point and hold-on time.
The LCD–8 controller is a model which operates from 24VAC
with the configu- rable hold-on time and temperature set point.
It controls heater loads up to 3 amps resistive or 3 amps
inductive. The operating temperature range extends from –40°F
to 140°F (–40°C to 60°C). The redesigned, patent pending,
rugged polycarbonate enclosure provides excellent protection
at temperature extremes, while allowing snow to shed to
prevent iglooing over the moisture sensor.
The internal magnetic reed switch allows for both configuration
and manual heater operation without the need for external
switches—which are susceptible to damage—or the need to open
the enclosure.
Verifying system functionality after installation or when
troubleshooting used to require spray circuit cooler or ice for
controller activation. The Sno-TestTM feature eliminates this
need by performing a self-test after power application and
operating heaters in a unique pattern for a few seconds.
Reading the test results takes only an AC voltmeter or clamp-on
ammeter.
A configurable snow sensor with two light-emitting diode (LED)
indicator lamps (Figure 2), the LCD-8 features a hold-on timer
which allows its system to operate to a drier surface after
melting snow.
The hold-on timer can be configured for off, 1 hour, 3 hours
or 5 hours. The operating temperature can be configured
for none (precipitation sensor), 36°F, 38°F or 40°F.
The low-temperature lockout (17°F), which disengages unit
operation, can be enabled or not.
Default configuration: 38°F operating temperature; 3 hour
hold-on; no lockout. The LCD-8 uses an internal magnetic
switch. The user swipes a magnet externally across this
switch to start a hold-on cycle or to terminate a running
hold-on cycle. This switch may also be used to reconfigure
the unit, or to view the current configuration.
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The green LED, ordinarily on steady, blinks to indicate a
concern with the unit. This LED is also used in the LCD-8’s
configuration process.
The yellow LED indicator is lit whenever the output relay is
powered (“on”).
There is an initialization period where the heaters are
tested.
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FIGURE 1
LCD-8 24VAC
Green LED
Ambient Air
Temperature
Sensor
Yellow LED
FIGURE 2
LCD-8 LED LIGHTS