3. POWER SUPPLY
3.1 Mains Operation
In general, the mains adapter ZB 5090-NA2 (12V DC, 800mA) is used for the
power supply to the instrument. It is connected to the socket U-DC (7) and is
locked by turning it to the right.
3.2 Operation with Rechargeable Battery (Option A)
With the option A, a 7.2V NiCd rechargeable battery with 1.5 Ah will be
installed, which allows, at a current consumption of approximately 15mA, an
uninterrupted operating time of 100 hours at minimum. The operating time will
be shorter when sensors are connected that require additional current (e.g.
humidity sensors FH A646 2mA or rotating vanes approximately 3mA) or the
serial interface (4mA). However, the sleep mode is meant for a long term
operation of the data logger. It allows for a measurement of approximately
30000 measuring cycles (see 7.6). An exact determination of the voltage of the
rechargeable battery and an estimation of the remaining operating time is
available with the measuring channel ´
Batt
´.
The supplied mains adapter ZB 5090-NA2 allows to recharge a discharged
battery within 2 hours. During the recharge process the green lamp of the
on/off switch (4) is continuously illuminated for charge control. (Attention! Due
to the heat build-up in the unit during this process, thermocouple
measurements with an internal VC may be erroneous!). If the green lamp
flashes, the battery is completely recharged and the charge circuit is switched
to trickle charging. As a result, the power supply can, during buffer operation,
remain connected to the measuring instrument. If the instrument is operated
with the rechargeable battery only, the green lamp in the on/off switch (4) is not
illuminated at all.
3.3 External Voltage Supply
It is also possible to connect another DC voltage 7...13V to the socket U-DC
(7). The cable ZB 5090-EK, fitted with 2 banana plugs, is available for the
connection. However, the electrically isolated supply cable ZB 3090-UK must
be used if an electrical isolation between power supply and transducers is
required or if a larger input voltage range 10...30V is required. It allows to
operate the measuring instrument with 12V or 24V mains supply.
3.4 Switch On/Off, Reinitialisation
If the power supply is properly connected the green lamp in the push button (4)
will be illuminated. If a rechargeable battery is installed the lamp is used for
charge control (see 3.2).
For
switching on
the instrument, the push button must be pressed. The red
control lamp aside will then be illuminated.
ALMEMO
3290-8
13
Power Supply
Summary of Contents for ALMEMO 3290-8 V5
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