Intermatic ET279C Owner/Installer Instruction Manual page 2

enclosure for the cover to swing open fully. (See Figure #1
and Figure #2). The time switch mechanism does not need to
be removed from the enclosure to mount the time switch since
the top mounting hole is a slotted type mounting hole. Secure
a screw or other fastener at eye level. The head of the
screw or fastener should be slightly larger than the
narrow portion of the slotted hole to ensure that the time
switch is securely held in place. The remaining two
mounting holes are accessible without removing the
time switch mechanism and will provide secure and
permanent mounting of the time switch.
2. To select momentary pulse operation you must remove the
time switch mechanism. Jumpers for selecting momentary
operation are enclosed, along with installation instructions in
the plastic bag. If you do remove the mechanism, refer to
Figure #1 and remove the mechanism from the case by
depressing the catch at the top of the case and pulling out.
CAUTION: DO NOT TOUCH THE CIRCUIT BOARD
COMPONENTS SINCE STATIC DISCHARGE COULD
DAMAGE THE MICROPROCESSOR.
3. Replace the mechanism in the case if it has been
removed.
4. Lift the left side of the insulator off of the retaining post
and pivot it up and away to expose the terminal strip.
5. Strip the supply and load wires by removing 1/2 inch of
insulation. DO NOT USE ALUMINUM WIRE. (See
figure #3, #4 or #5). Insert the wire ends under the proper
terminal plates and tighten the screws firmly. Use AWG
#10 through #18. Connect ground wire to grounding
terminal at bottom of case.
6. Replace the plastic insulator.
7. Be sure that the battery is functioning properly. This can
be checked by making sure the display is visible. If the
display has scrambled information, press the RESET
switch and hold for three to five seconds. Note that the
battery can easily be replaced without removing the time
switch mechanism or field wiring. Simply press in and down
ward (in the direction of the arrow) on the battery cover which
is identified with the word "Battery". It is recommended that
the battery be replaced with a "AA" industrial grade alkaline
cell at two to three year intervals as part of the normal
time switch maintenance
markings when installing. No other maintenance is
required.
8. Place the selector switches in the AUTO and CLK
position.
9. Reapply power to the time switch.
10. Press the reset switch for three to five seconds. The
display will now show 12:00 A.M. and day #1. Note that
the days of the week are numbered 1 through 7 for
Sunday through Saturday. The timer is now ready for
programming. Refer to the chart which follows and
enter the scheduled events (set points or pulse outputs)
required. Assign each of the 20 set points (EVENTS) entered
to whichever day or days of the week you wish an ON or
OFF operation to occur. Simply put a check in the box
that applies. Note that programming two off times in
sequence, allows the user to manually turn a load on,
after normal working hours for example, and allows the
time switch to automatically turn the load back off. This
is an energy saving feature which allows loads to be
manually switched on after normal occupancy times,
but provides for automatic off switching of these loads.
Note that several off times in a row can be programmed
to provide several "auto off" times.
observing battery polarity
FIG. #1
Mounting Holes
Knockouts
FIG. #2
Maintained Output Both Output 1 and 2
TIMER
POWER
LINE 1 LINE 2
LOAD
For switching 2 loads
on different schedules.
FIG. #3