S8M
Troubleshooting
If the S8M is not operating properly, check the items listed in the following table before requesting repairs.
Stage Observed problem Possible cause Remedy
Installation The S8M was installed on a DIN Rail,
but the bottom of the Unit is not
attached.
The S8M's bottom latch is not mounted
properly.
Check that the S8M has been pressed
until the bottom latch clicks.
Parameter setting The desired alarm value is not being
displayed.
The setting is not allowed in the present
protection level.
Change the protection level setting.
The set value was changed, but the
change wasn't accepted.
The new setting was not saved. After pressing the Up and Down Keys to
change the set value, press the Mode
Key and verify that the setting flashes
and the setting is saved.
When the S8M was switched to Run
Mode after setting the overvoltage
alarm and undervoltage alarm, the
alarm output turned ON and cannot be
cleared.
The undervoltage and overvoltage
settings may have been reversed.
Switch to Setting Mode and check the
settings.
Equipment setup The display is flashing “ON” in Test
Mode, but power is not being supplied
by the outputs.
A flashing “ON” display indicates that
the S8M is waiting to turn ON the
outputs.
If the Mode Key is pressed, the output
will be connected and power will be
supplied.When power is being
supplied, “OFF” will flash on the display.
The S8M was turned OFF in Test Mode,
and there was no power from the
outputs when the S8M was turned ON
again.
If the power is turned OFF in Test
Mode, all of the branch outputs are cut
off for safety reasons.
Either connect all branch outputs in
Test Mode or connect each branch
output individually.
When the output is connected in Test
Mode, it is cut off immediately and can't
be connected again.
Check whether the status indicator is lit
red. The current may be higher than the
tripping current.
Check for problems such as output
wiring problems.If no problems are
found, press the Reset Key for at least
3 s.
Operation The displayed temperature is clearly
different from the ambient temperature.
The S8M detects the Unit's internal
temperature, which can be 5 to 10°C
higher than the ambient temperature.
When the alarm is being used as a
control signal for a fan or cooling
equipment, set the alarm value based
on the graph in the S8M User’s Manual
(Cat. No. Z241).
An alarm was output and the cause of
the alarm was eliminated, but the alarm
display cannot be cleared.
The S8M doesn't disregard temporary
errors, so the alarm display is retained
even after the cause of the alarm is
cleared.
The alarm can be cleared by pressing
the Reset Key for at least 3 s.
The peak output current value is not
displayed and the display shows “- - -”.
The current may have exceeded the
measurable range.
Clear the peak output current value in
Run Mode.
The circuit was not designed for a
current that high, but the circuit is cut off
as soon as power is supplied.
The abnormal current tripping type
(detection method) may be set to
“instantaneous.” With instantaneous
detection, an abnormal current is
detected very quickly and the circuit
may be cut off due to excessive current
during equipment operation.
Either change the abnormal current
tripping type from instantaneous to
standard or raise the current tripping
value.
There may be a large number of
devices connected to the output.The
more devices that are connected, the
higher the operating current.
Use the S8M's startup sequence
function to spread out the connections
to the devices (delay the connection of
some devices).
Branch output cut off The connection cannot be reset
immediately after it is cut off.
To protect the S8M's internal circuits, at
least 15 seconds must pass before a
cut-off output can be reset.
If “RST” is displayed when the Reset
Key is pressed for at least 3 s, the cut-
off output can be reset when 15 s has
passed since the output was cut off.
The output was reset, but it was
immediately cut off again.
The original cause of tripping may not
have been eliminated. After resetting
the error, a large current may have
flowed again.
Eliminate the cause of the cutoff and
press the Reset Key for at least 3 s.
Maintenance The run time alarm went OFF, so the
equipment was checked and other
parts were replaced, but the alarm
could not be cleared.
The S8M continues adding to the run
time. The run time must be reset to 0 in
order to clear the alarm.
Clear the run time.
In the interest of product improvement, specifications are subject to change without notice.
ALL DIMENSIONS SHOWN ARE IN MILLIMETERS.
To convert millimeters into inches, multiply by 0.03937. To convert grams into ounces, multiply by 0.03527.