Omron S8T-DCBU-01 Manual page 5

2. Turn the Battery Holder switch OFF or the SW shown in Fig-
ure 2. Unnecessary backup operation shortens the battery
service life for the following two reasons. When turning the
AC power OFF, be sure to turn the Battery Holder switch ON
or the SW shown in Figure 2.
• Full charge requires 24 to 28 hours. Activating backup
operation before charging fully shortens the battery ser-
vice life due to insufficient charge.
• Every time charging and discharging is repeated, the bat-
tery service life is shortened.
3. When battery connector terminal voltage drops to 15.5 V
(typical) or below, S8T-DCBU-01 stops charging due to the
erroneous battery connection protection function. When the
battery nears end of life (when the battery capacity be-
comes less than half of the original capacity), if only AC
power is turned OFF and the unit is left in this condition for
2 days (under the temperature of 25°C), backup operation
may be disabled due to inability to recharge. (Refer to Pro-
tection Against Erroneous Battery Connection on page 47.)
4. Do not use batteries in an area where corrosive gases (sili-
con gas, sulfide gas, organic gas, chlorine gas) may enter.
If the relay ("X" shown in Figure 1 and 2) or switch (Battery
Holder, SW shown in Figure 2) is exposed to corrosive gas-
es for an extended period, the contact surface corrodes,
causing unstable or loose connection, thus disabling re-
charge or backup operation.
5. The following table shows the ambient temperature and hu-
midity when using LY1-D (24 VDC). LY1-D (24 VDC) has a
built-in diode in order to absorb counter-voltage generated
by the operation coil. As this causes polarity in the opera-
tion coil, be careful when wiring. Refer to the individual cat-
alogs for details.
Ambient temperature
Output current 4 A or under: −25 to +55°C
LY1-D
Output current 4 A or over: −25 to +40°C
(24 VDC)
6. On the SW shown in Figure 2, voltage and current increase
to 15 V when opened and 2 mA when short-circuited. Be
careful when selecting the switch.
7. The standby current becomes live and discharging is has-
tened even when AC power is not wired, but the battery is
left wired.
8. Should the operator forget to turn off the Battery Holder
switch in Figure 1 or the SW in Figure 2, the backup opera-
tion continues until the battery connecting terminal voltage
drops down to 18.5 V (typical), then the battery is discon-
nected by the relay (X). If the battery is left in this condition
for a long time exceeding the period of time shown in the ta-
bles below, the overdischarge is hastened due to self-dis-
charge, thus disabling backup operation due to inability to
recharge.
Battery Ambient Load
tempe- current
rature
LC-@122 20 °C 0.11 A
R2@@
2.2 A
40 °C 0.11 A
2.2 A
LC-@123 20 °C 0.17 A
R4@@
4.8 A
40 °C 0.17 A
4.8 A
Ambient humidity
5 to 85%
Length of months that
disables recharge
Battery Battery
service life service life
early stage ending stage
1.0 month 0.5 months
2.0 months 1.0 month
0.5 months 0.25 months
1.0 month 0.5 months
1.0 month 0.5 months
3.0 months 1.5 months
0.5 months 0.25 months
3.0 months 1.5 months
Figure 1. Overcharge protection circuit when operator
forgets to turn Battery Holder switch OFF
L N −
+
S8TS
-06024@
−V −V
+V
X
LOAD
When forgetting to turn Battery Holder switch OFF:
1. Start backup operation after turning OFF AC power.
2. When the battery connecting terminal voltage drops down to
18.5 V (typical), the backup operation stops, opening the relay point and
disconnecting the battery from the body.
Figure 2. Overcharge protection circuit using external
signal (Backup ON/OFF input)
L N −
+
S8TS
-06024@
−V −V
+V
X
LOAD
1. Open the backup ON/OFF input terminals by external signal (switch)
(Backup becomes impossible.)
2. When AC power is turned OFF, 24 VDC drops, opening the relay point
and disconnecting the battery from the DC Backup Block body.
(3) Self-discharge of the battery
The battery self-discharges even when it is disconnected from
the S8T-DCBU-01. When transporting or storing the unit for long
hours, charge the battery at the intervals specified below to pre-
vent overdischarge.
Ambient temperature
Under 20 °C
20 to 30 °C
30 to 40 °C
DC Backup Block for S8TS
S82Y-TS01 (Battery Holder)
X
1
3
5
7
LY1-D (24 VDC)
S8T-DCBU-01
Specified relay (X): LY1-D (24 VDC)
<OMRON> (See Note 5)
S82Y-TS01 (Battery Holder)
X
SW (See note 6.)
(Backup ON/OFF Input)
S8T-DCBU-01
Specified relay (X): LY1-D (24 VDC)
<OMRON> (See Note 5)
Charging intervals
9 months
6 months
3 months
S8T-DCBU-01
2
4
6
8
X
L-43