King Electric DS-824 - Manual (Page 3)

Fine Adjustment for Efficient Operation
The DS-824 is shipped with the TEMP and DEL adjustments in the center position, representing 39°F
(3.9°C) and 30 minutes of Delay-Off time respectively. The Sensitivity control is set for highest sensitivity.
Depending on local conditions the user may find that fine adjustment of the controls may provide more
satisfactory operation. If the sensor does not trigger during very wet snows the trigger temperature may
need to be adjusted higher. Conversely, if the user notices false triggers during cold rains that do not
freeze, the trigger temperature may need to be lowered. Locations susceptible to blowing ground snow or
snow falling from eaves or trees may benefit from a lower sensitivity adjustment. The Delay-Off time can
also be adjusted or the range expanded using the LD configuration switch to provide clean melt-off without
excessive running time. Fine adjustment can both save operating expense and provide more reliable
operation. However, to keep reliability high, always make adjustments in small increments.
ALWAYS USE CARE WHEN REPLACING THE ENCLOSURE FRONT COVER!
Be sure the front cover gasket is not pinched or rolled. Do not overtighten the front cover screws.
Manual Override Switch Operation
An override switch mounted on the side is provided for testing and special operational requirements.
Placing the switch in the “Automatic” position will allow the sensor to operate normally, activating the
controlled equipment as needed. Placing the switch in “Manual On” will close the load relay, activating the
controlled equipment. The “Standby/Reset” position prohibits triggering of the unit, clears any active delay
timer, and opens the load relay. In order to reduce excessive runtime for the heater the “Manual On”
mode will remain in effect for a maximum of 40 hours, then return to “Automatic” mode even if the
switch is still in the “Manual On” position. You may put the DS-824 back into “Manual On” mode by
switching to “Automatic”, then back to “Manual On”. This will restart the 40 hour timer.
If the override switch is placed in “Manual On” for less than 2 seconds, then switched back to
“Automatic” the controller will execute one delay off cycle. This can be used to clear a frost or hail
buildup without the danger of leaving the system in a continuous “Manual On” condition. “Standby/Reset”
can still be used to clear this delay off cycle.
External Control/Monitor Operation
An external control/monitor jack is provided on the DS-824. Order
the optional CS-1 control/monitor cable to access this feature.
Connecting Black to White will activate the “Manual On” function.
Connecting Green to White will activate the “Standby/Reset” function.
The Red/Orange leads are connected to an internal low power
monitor relay. This relay, rated at 24 VAC/VDC at 400 ma, will close
with the load relay and can be used to externally monitor activation of
the sensor.
Precipitation Grid Maintenance & Replacement
It is recommended that the DS-824 be powered down and the grid wiped clean with clear water at least once
every 4 months. Heavy deposits may be removed using a non-metallic scouring pad (Scotch-Brite
TM or
equivalent.) However, after a number of years, the corrosive elements left behind when water is evaporated
out of the precipitation grid will eventually damage the grid rings. The precipitation grid can be easily
replaced by ordering and installing a new MG-3 “Moisture Grid Assembly”. Reference the “Moisture
Sensor Mounting & Termination” section for information on replacing the precipitation grid.
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The DS-824 can be mounted by screwing the base conduit hub onto an appropriate size free-standing
conduit or by using the mounting holes in each corner of the enclosure.
DO NOT DRILL HOLES THROUGH THE ENCLOSURE FOR MOUNTING!
This can allow water into the enclosure causing a potential shock or fire hazard. It is recommended that a
weatherproof condulet or junction box be mounted below the DS-824 for termination of the power and load
pigtails to the building wiring.
ALWAYS USE CARE WHEN REPLACING THE ENCLOSURE FRONT COVER!
Be sure the front cover gasket is not pinched or rolled. Do not overtighten the front cover screws.
Delay Adjust
Temp Adjust
Sensitivity Adjust
Probe Jack
Grid Jack
Switch Jack
Control/Monitor Jack
LED Jack
Configuration Switch
Load
Input Power
Setting the Configuration Switches and Adjustments
The following table outlines the operating modes for the DS-824 and explains the
functions of the adjustments. Trigger temp (TT) is adjustable from 34
°F-44°F
using the “Temp Adjust” control. When ambient air temperature (AT) is below
this trigger point precipitation is assumed to be snow. When above this
temperature, precipitation is assumed to be rain. The SNOW switch will cause
the sensor to activate when snow is detected. The RAIN switch will cause the
sensor to activate when rain is detected.
The DEL configuration switch activates the “Delay Off” drying
cycle timer on the DS-824. The timer allows the DS-824 to dry the
heated surface through evaporation once precipitation has
stopped. The drying cycle reduces the chance of moisture left
behind refreezing into ice. The Long Delay (LD) configuration
switch determines the time span of the drying cycle. LD off sets a 30-90 minute span. LD on sets a 2-6 hour
span. This timer is restarted by each precipitation detection. Therefore, the DS-824 will continue to operate
as long as precipitation is detected, then for the Delay Off period once precipitation has stopped. All
"sensor" modes (DEL off) provide a 2 minute closure to reduce cycling of an external controller. When
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Pin Color Function
1 Green Standby/Reset
2 Black Manual
On
3 Orange Deice On Mon
4 Red Deice On Mon
5 White Return