Data Sheet 85098-0003 Issue 2
Not to be used for installation purposes. Page 7 of 10
accurate as the master clock. See the Associated Equipment list for
the appropriate master clocks.
Installation of the Model 24D40A clock offers the following options:
• For new installations, the 24D40A can be mounted into either a
standard 4-gang masonry backbox or an 8A425 Surface-Mount
Backbox, and can be operated from a 24Vac power supply.
• For upgrade installations, the 24D40A can directly replace a
Model 24D20 Two-Inch Digital Clock. Both units fit into a standard
4-gang backbox and share the same pigtail connector. (Check
power supply reserve capacity before upgrading.)
• In existing installations, the 24D40A clock can directly replace the
GE Model 24F750A Digital Clock. The 24D40A fits into the same
six-gang backbox and operates from the existing 15Vdc power
supply. The pigtail connector of the existing installation can be
directly applied to the new 24D40A 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 24D40A clock meets the requirements
for installation in educational, institutional, and commercial sites.
The installed clock is ESD-hardened to IEC 801-2 Standards.
Engineering Specification
The Four-Inch Digital Secondary Clock shall be GE Model 24D40A or
an approved equal. The digital clock shall provide an even-intensity,
long-life time display in selectable 12- or 24-hour format. Each min-
ute, the secondary clock shall receive a time display update from
the master clock.
The four-inch digital secondary clock shall fit into a standard four-
or six-gang backbox and shall offer adequate backbox clearance to
reduce the possibility of shorts. The clock shall operate from either
a 24Vac or 15Vdc power supply. The clock shall offer two display
modes, either Normal or Bright intensity. The Model 24D40A clock
shall include pigtail plug-in lead connectors. The unit shall directly
replace GE Model 24F750A and 24D20 digital clocks.
The clock shall comply with the FCC Part 15 Class A emissions
rules, and shall meet requirements for installation in educational,
institutional, and commercial sites. The installed clock shall also be
ESD-hardened to the IEC 801-2 Standard.
Mounting Wall-mounted using two-gang masonry box
Ceiling-mounted using conduit extensions
Finish Charcoal gray
Specifications: 24D40A Four-inch Digital Secondary Clock
Mounting New Installations (flush mount): RACO #693, 4-gang
masonry backbox, 2-1/2 in (6.4 cm) deep, or RACO
#698, 3-1/2 in (8.9 cm) deep, or approved equal
Retrofit Installations (surface mount): GE 8A425, Four-
Inch Digital Clock Surface-Mount Backbox, 1-1/2 in
(3.8 cm) deep, or approved equal
Upgrade Installations (to replace 24F750A clocks):
RACO #960, 6-gang masonry backbox, 3-1/2 in deep
(8.9 cm), or approved equal
Power
Requirements
24Vac (+/– 5Vac) NOT TO EXCEED 30Vac
350mA in Bright display mode @ 24Vac
250mA in Normal display mode @ 24Vac
For replacement of 24F750A: (see Note below)
15Vdc (+ 0/-2Vdc)
350mA in Bright display mode @ 15Vdc
250mA in Normal display mode @ 15Vdc
Note: When replacing 24F750A clocks, the pigtail plug from the previous clock
can be directly connected to the 24D40A without rewiring. The rated current
consumption of the 24F750A is 300mA, allowing direct replacement at the Normal
intensity setting. If the Bright setting of the 24D40A is to be used, the existing loading
on the power supply must be measured to see if there is sufficient supply capacity.
Viewing Distance 160 ft (48.8 m) in the Bright intensity mode with
normal lighting 150 ft (45.7 m) in the Normal intensity
mode with normal lighting
Display Size 4 in (10.2 cm) high by 10 in (25.4 cm) wide
Electrostatic
Discharge
Installed 24D40A is ESD-hardened to IEC 801-2
requirements (+/– 8kV direct, +/– 15kV air discharge)
Terminations Pigtail leads color-coded to match GE Clock Cables
176-299 and 176-499
Lens Anti-glare Acrylic
Dimensions 5.8 in (14.7 cm) high by 19.0 in (48.3 cm) wide by 2.5 in
(6.4 cm) deep
Weight 2.5 lbs (1.1 kg) (without packaging)
Bezel Charcoal gray ABS plastic, 5.8 in (14.7 cm) high by
19.0 in (48.3 cm) wide by 0.94 in (2.4 cm) deep
176-299 and
176-499
GE Clock Cable, 14-gauge, five-circuit, color-coded
with designations on the jacket. Model 176-499 is a
plenum rated version of Model 176-299.
8A425 Surface Mount Clock Backbox, 19 in (48.3 cm) long by
7 in (17.8 cm) high by 1.5 in (3.8 cm) deep, charcoal
gray enamel finish. Low profile box allows the 24D40A
to be mounted on an existing wall surface.
110-3693 AC Clock Power Supply, 5 amps (rms), mounts in a
145-184 Power Supply Backbox with either a 110-
2190 flush-mount door or a 110-2191 surface-mount
door (order separately according to your application’s
requirements). Three power supplies maximum per
backbox.
110-3902 Four-inch Digital Clock Dual Enclosure, Wall or Ceiling
Mount
The Model 24D40A Four-Inch Digital Secondary Clock can be controlled by
any of the following master clock products:
Note: Correction by MCS350 or selected StarCall may require use of Model
110-3836 Digital Clock Sync Module.
24A701 GE Master Clock (rack-mount)
24A702 GE Master Clock (wall-mount), flush with backbox
MCS350 GE Intercom System with Master Clock
SCR+ GE StarCall/StarCall Plus/StarCare Platform Integrated
Communications Systems with the Model 437-00125
Master Clock Feature Package 1
24DS250 Digital Clock/speaker
Attractive digital clock/speaker
Two-inch high LED display
Eight-inch speaker
Dual voltage transformer
Metal grille
24DS250 Digital Clock/Speaker
The GE Model 24DS250 Digital Clock/Speaker is an attractive unit with
a GE Model 24D20 Two-Inch Digital Secondary Clock and a Model
5A606 Speaker with a dual voltage impedance-matching transform-
er. The LED display is 2 in (5.1 cm) high, and is highly visible.
The digital clock shows time in either 12- or 24-hour format. The
baffle is 14-1/4 in (36.2 cm) high, 14-1/4 in (36.2 cm) wide, and 3 in
(7.6 cm) deep. The grille is black perforated steel, and the frame is
extruded aluminum with a dark gray finish. When flush mounted
using the 145-192 backbox, the clock housing protrudes only 0.82 in
(2.1 cm) from the wall surface.
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