Daktronics DataTime Outdoor LED Time & Temperature Displays - Manual (Page 15)

Installation with Ground and Neutral Conductors Provided. For this type of installation,
the power circuit must contain an isolated earth-ground conductor. Under this circumstance,
do not connect neutral to ground at the disconnect or at the display. This would violate
electrical codes and void the warranty. Use a disconnect so that all hot lines and neutral can
be disconnected. The National Electrical Code requires the use of a lockable power
disconnect within sight of or at the display.
Installation with Only a Neutral Conductor Provided. Installations where no grounding
conductor is provided must comply with Article 250-32 of the National Electrical Code. If the
installation in question meets all of the requirements of Article 250-32, the following
guidelines must be observed:
• Connect the grounding electrode cable at the local disconnect, never at the display
driver/power enclosure.
• Use a disconnect that opens all of the ungrounded phase conductors.
3.3 Lightning Protection
Using a disconnect near the display to completely cut all current-carrying lines significantly
protects the circuits against lightning damage. This is also a National Electrical Code
requirement. For the disconnect to provide protection, the power must be disconnected when
the display is not in use. The DM-100 control console should also be disconnected from
power and from the signal J-box when the system is not being used. The same surges that
may damage the display's driver can also damage the DM-100 console's circuit.
3.4 Signal Connection
Reference Drawings
4 Column MASC Specifications ............................................................. Drawing A-166216
Time & Temp Power/Signal Hookup ...................................................... Drawing A-938369
Enclosed Driver, 4 Column Reference................................................... Drawing A-938300
Route power and signal cables into the display from the side or rear. There are 7 /
8
" knockouts
for ½" conduit fittings on the sides of all DataTime cabinets and on the back panels. All
power and signal wiring terminates at the driver enclosure.
To access the driver enclosure, open the access door and remove the cover. Refer to the Shop
Drawings for the access location for the display. For displays with 10”, 13”, 18” and 24”
digits, access to interior components is gained by turning the latches on the hinged doors.
Electrical Installation 11