(3) Push the fluorescent lamp to be replaced in
(1) Disconnect electrical cable from the clock
against the spring-loaded lampholder and pull lamp out of
(2) Hold clock and remove four 10-32 screws, flat-
the stationary lampholder and out of lamp housing.
washers, and lockwashers which attach clock to the ceiling
(4) Place new lamp in spring-loaded lampholder,
mounting plate. Remove clock.
push against the lampholder, and place the opposite end of
the lamp into the stationary lampholder.
b. Installation of Clock.
(1) Hold clock to ceiling mounting plate and insert
the four 10-32 screws, flatwashers, and lockwashers which
secure the clock.
(2) Disconnect the power cord to the map board
(2) Connect electrical cables to the clock chassis.
(3) Disconnect the three black wires from the
5-11 REPLACEMENT OF ROTARY CHAIR COMPO-
terminals of the switch to be replaced.
N E N T S . The following paragraphs provide procedures for
( 4 ) Loosen and remove the panel nut holding the
replacement of tie down assembly and roll pin. Figure 2-1
switch to the lamp housing. Remove old switch.
illustrates the rotary chair and its components.
( 5 ) Put new switch in place and secure with panel
a. Turn chair over and remove tiedown assembly by
(6) Connect the three black wires to the appropriate
knocking out spring pin holding tiedown assembly to stem.
terminals of the switch.
Use a standard 3/16-inch punch and hammer.
( 7 ) Reconnect the plug to the light assembly and
b. Pull old tiedown assembly away from stem of chair.
replace the lamp.
c. I n s t a l l n e w t i e d o w n a s s e m b l y o n s t e m o f c h a i r ,
(8) Turn the light onto test the new switch.
aligning hole in tiedown to hole in the stem.
( 9 ) Replace light fixture and secure it to the map
d. Install new spring pin by driving it in place with a
board. Replace the lamp housing faceplate.
Replace the telephone as follows:
( 2 ) Remove the two sets of hardware securing the
a. Disconnect the power plug of telephone.
ballast to the lamp housing. Remove the bare ground wire
b. Disconnect the straight plug from the telephone.
twisted under the ballast.
c. Remove the six sets of hardware securing the tele-
(3) Cut one of the ballast wires behind the crimp.
phone mounting panel assembly to the electrical duct
(4) Fasten the corresponding wire of the new ballast
extension. Pull the telephone panel out and set it on the
to the open end wire just cut with a solderless butt connec-
tor using a crimping tool.
d. Remove the three hardware sets securing the tele-
(5) Repeat steps (3) and (4) for the other four wires
phone to the telephone mounting panel.
of the ballast. Be sure wiring is in accordance with figure
e. A t t a c h t h e n e w p h o n e t o t h e t e l e p h o n e m o u n t i n g
(6) Sandpaper around the holes for the ballast on the
f. Secure the mounting
inside of the light unit housing.
( 7 ) Secure new ballast to lamp unit housing with
g. Connect the straight plug to the telephone and the
power plug to the electrical duct extension assembly.
( 8 ) Replace lamp and restore power to the lamp.
Test the light to see if it works.
(9) Replace faceplate on the lamp housing.
5-13 REPLACEMENT OF PENCIL SHARPENER. F o r
5-10 REPLACEMENT OF DIGITAL CLOCK READOUT
removal and replacement of pencil sharpener, remove
assembly hardware sets securing pencil sharpener, Remove
a. Removal of Clock.
old sharpener and install new sharpener in its place.