7. Power supply
7. POWER SUPPLY
Power can be supplied to the measuring instrument in any of the following
ways : 3 AA alkaline batteries (included in delivery)
Mains adapter 12V, 0.2A with ALMEMO
®
connector
ZA1312-NA1
Electrically isolated power supply cable (10 to 30 VDC, 0.25 A) ZA2690-UK
12V DC clamp connector to socket DC (options U and I)
ZA1000-FSV
Our product spectrum includes all the appropriate accessories.
7.1 Battery operation and supply voltage monitoring
Power is supplied to the measuring instrument as delivered by 3 AA batteries.
At a current consumption of approx. 10 mA the operating time will be approx.
250 hours. The current operating voltage is displayed each time the the device
is switched on; this gives you a basis for estimating the remaining operating
time. When the remaining battery capacity drops to approx. 10 percent, the
LO-
BAT
arrow will appear in the display. If the batteries are completely discharged
the device will switch off. To replace old batteries first unscrew the battery
compartment cover (7) on the rear of the device.
7.2 Mains operation
The ALMEMO
®
2450-1 can be supplied with power from an external source
preferably using mains adapter ZA 1312-NA1 (12 V / 0.2 A) via the
DC
socket
(4). Please ensure that the mains voltage is correct.
7.3 External DC voltage supply
The
DC
socket (4) can also be used to connect another DC voltage, 10 to 30 V
(minimum 200 mA). This is via an ALMEMO
®
connector (ZA1000-KS). If, how-
ever, the power supply has to be electrically isolated from the transducers, then
option U (OA 2450-U) is needed or electrically isolated supply cable ZA 2690-UK
must be used It will then be possible to use the measuring instrument in a 12-volt
or 24-volt on-board supply system.
7.4 Sensor supply
At the ter (plus) and – (minus) in the ALMEMO
®
connector there is a 9-
volt sensor supply voltage available (maximum 150 mA) (self-healing fuse, 500
mA). Other voltages (12, 15, or 24 V or references for a potentiometer and
strain gauge) can be obtained using special connectors;
(see Manual 4.2.5 and
4.2.6)
.
7.5 Switching ON / OFF, reinitialization
To switch the device ON
briefly press and release the key
ON OFF
r
(6) in the
middle of the keypad; to switch the device, OFF press and hold down the key
ON OFF
r
. After the device is switched off all saved values and settings are re-
tained intact; (see 7.6).
If interference (e.g. electrostatic) or a malfunction (e.g. battery failure) causes
14 ALMEMO
®
2450-1
