Precautions during usage
1. Output setting
• ON setting: Turn the setting element
inward, and red mark appear around the
• OFF setting: Turn the setting element
outward, and the above red mark will dis-
• Turn the setting element sufficiently
until the click action is felt.
2. Clock setting
• Be sure to turn the knob at the clock
center in the arrow direction to set the
clock to the present time. (The dial also
turns together with the clock.) Be sure to
prevent reverse turning.
• do not turn the dial to set the clock.
• Insert the time switch from the front of
the attachment panel.
(One-touch system: Panel attachment
• Either use 3.8 or M4 wood screws for
attachment, or use DIN rails with a width
of 35 mm (ATA48011). (Direct-attach-
4. Contact relay operation if the power
• Contact relays remain closed while the
power is off.
Time switch setting time
5. Power failure compensation (ATB75
• An internal nickel cadmium battery is
provided to compensate for power fail-
ures, but the power supply should be left
on as much as possible. Turning the
power supply on and off shortens the
service life of the battery.
• After continuous charging for 48 hours,
the battery provides 200 hours of power
failure compensation. The internal bat-
tery is fully charged, but if the battery
capacitance has dropped because of
natural discharging, or if the battery has
discharged completely, there may be
times when the switch does not operate
immediately when the power is turned
on. If this happens, set the clock to the
proper time after the power has been
back on for three to four hours.
• Nickel cadmium batteries are a valu-
able commodity which can be recharged.
They cannot be replaced, but if being
discarded after use, please make sure
they are recycled if possible.
When discarding the battery, turn off the
power supply to the time switches, and
use radio pliers to disassemble the over-
all connections and remove the battery.
6. Precautions concerning wiring
With panel attachment models, wiring
should be connected by soldering it
directly, or using the #187 flat connecting
probe provided as an accessory.
7. CE marking support
1) EMC directives (89/336/EEC)
The A-TB72 flat time switch conforms to
EMC directives as a stand-alone time
Applicable standards: EN50081-2,
2) Low-voltage directives (73/23/EEC)
In order to satisfy VDE0435 Part 2021,
the installation conditions and precau-
tions noted below must be observed.
1. Wiring connections
The power supply applied to the time
switches should be protected by an over-
current protection device that conforms
to EN/IEC standards.
2. Attachment and removal
(1) With panel attachment models, the
time switches are designed for attach-
ment to a panel. The ends of the time
switches should be fitted inside the
(2) With direct-attachment models, the
time switches are designed to be
installed inside the panel. Do not touch
any component of the time switch, such
as the end section, while power is being
(3) When attaching or removing the
switches, check first to make sure no
voltage is being applied to any of the end
3. Do not use these time switches in
safety circuits. For example, if using the
time switches in heat circuits or similar
circuits, a protective circuit should be
provided on the mechanical side.
8. For other information, please refer to
"Precautions Concerning A-TB Time