Data Sheet 85098-0003 Issue 2
Not to be used for installation purposes. Page 6 of 10
110-3902 Dual Four-inch
Digital Clock Housing
Designed for GE four-inch
digital secondary clocks
Adaptable for wall or ceiling mounting
The GE Model 110-3902 Dual Four-Inch Digital Clock Housing is de-
signed for corridors or large rooms requiring a front and rear digital
clock display. The enclosure houses two GE Model 24D40A/A Four-
Inch Secondary Digital Clocks (purchased separately), and uses the
trimplates that come with the digital clocks.
The dual digital clock housing can be wall or ceiling-mounted. For
mounting to a cement or cinder block wall, the housing mounts to
a standard RACO two-gang masonry box. Optionally, the housing
can be flush-mounted to a ceiling or suspended below the ceiling
using conduit extensions. Although not recommended, the housing
can also be mounted to a stud wall if additional structural support
is provided, or mounted to the ceiling after creating a support frame
out of 2x4s.
Specifications: 110-3902 Dual Four-inch Digital Clock Housing
Dimensions 7 in (17.8 cm) high, 19 in (48.3 cm) wide, 4-1/2 in
(11.43 cm) deep
Weight 4.4 lbs (2 kg), less backbox and clocks
Mounting Wall-mounted using two-gang masonry box
Ceiling-mounted using conduit extensions
Finish Charcoal gray
24D20A Two-Inch Digital
Secondary Clock
Highly visible two-inch LED
24 Vac operation
Selectable LED display intensity
12- or 24-hour display
High efficiency
Can replace model 24F750A clocks for easy upgrades
ESD-hardened
The Dukane Model 24D20A Two-Inch Digital Secondary Clock
provides a highly visible, even-intensity, long-life display of time
in selectable formats. It can be operated in either 12- or 24-hour
format, and at either Bright or Normal intensity levels. The time
display on the secondary clock updates to the master clock time
at one-minute intervals. This ensures that all system clocks are in
precise synchronization, and that every clock in the system is as
accurate as the master clock. The high-efficiency 24 Vac design
allows many clocks to be operated at great distances from low cost
24 Vac power supplies.
For new installations, the 24D20A can be flush-mounted into
a standard four-gang backbox, and can be operated from a 24
Vac power supply.
In retrofit installations, the 24D20A can be surface-mounted
using the 8A225 Surface Backbox, and can be operated from 24
Vac.
In repair situations, the 24D20A can directly replace the
24F750A digital clock. The 24D20A fits into the 24F750A’s exist-
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ing six-gang backbox and operates from the existing 24F750A’s
15Vdc power supply. The pigtail connector of the existing instal-
lation can be directly applied to the new 24D20A installation
without rewiring. (Check power supply reserve capacity before
upgrading.)
Compliance with FCC Part 15 Class A emissions rules has been veri-
fied. As a result, the Model 24D20A clock meets the requirements
for installation in educational, institutional, and commercial sites.
The installed clock is ESD-hardened to IEC 801-2 Standards.
Specifications: 24D20A Two-Inch Digital Secondary Clock
Mounting
New Installations (flush-mount): RACO #693, 4-gang
masonry backbox, 2-1/2" (6.4 cm) deep, or RACO #698,
3-1/2" (8.9 cm) deep, or approved equal.
Retrofit Installations (surface mount): Dukane 8A225,
Two-Inch Surface-Mount Backbox, 1-3/4" (4.4 cm) deep,
or approved equal.
Repair Installations (to replace 24F750A clocks): RACO
#960, 6-gang masonry backbox, 3-1/2" deep (8.9 cm),
or approved equal.
Power
Requirements
24Vac (+/– 5 Vac)—NOT TO EXCEED 30 Vac
122 mA in Bright display mode. (3W) @ 24Vac
67mA in Normal display mode (1.6W) @ 24Vac
For
replacement of
24F750A clocks:
15Vdc (+ 0/–2Vdc)
125mA in Bright display mode @ 15Vdc
60mA in Normal display mode @ 15Vdc
Note: When replacing a 24F750A clock, the pigtail plug from the previous clock
can be directly connected to the 24D20A without rewiring. The rated current
consumption of the 24F750A is 300mA, allowing direct replacement at either Bright
or Normal intensity settings.
Viewing
Distance
110' (33.5 m) in Bright intensity mode with normal
lighting
100' (30.5 m) in Normal intensity mode with normal
lighting
Display Size 2" (5.1 cm)
Electrostatic
Discharge
Installed clock is ESD-hardened to IEC 801-2
requirements (+/– 8kV direct, +/– 15kV air discharge)
Terminations Pigtail leads color-coded to match Dukane clock cables
176-299 and 176-499
Lens Anti-glare clear acrylic
Dimensions 4-1/2" (11.4 cm) high by 11-15/16" (30.3 cm) wide by
1-3/4" (4.4 cm) deep
24D40A Four-inch Digital
Secondary Clock
Highly visible four-inch LED
24Vac operation
Selectable LED display intensity
12- or 24-hour display
High efficiency
Can replace GE model 24D20 and 24F750A clocks for easy
upgrades
ESD-hardened
The GE Model 24D40A Four-Inch Digital Secondary Clock provides
a highly visible time display. It can be operated in either 12- or
24-hour format, and at either Bright or Normal intensity levels.
Each minute the time display on the secondary clock updates to
the master clock time. This ensures that all clocks in the system are
in exact synchronization, and that every clock in the system is as
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