Campbell Scientific CR3000 Micrologger - Manual (Page 83)

Section 7. Installation
83
Power supplies available from Campbell Scientific can be reviewed in the
appendix Power Supplies
(p. 566),
or at www.campbellsci.com. Contact a Campbell
Scientific application engineer if assistance in selecting a power supply is needed,
particularly with applications in extreme environments.
7.4.1 CR3000 Power Requirement
The CR3000 operates on dc voltage ranging from 9.6 to 16 Vdc. It is internally
protected against accidental polarity reversal. A transient voltage suppressor
(TVS) diode on the 12-Vdc power input terminal
(p. 35)
provides transient
protection by clamping voltages in the range of 19 to 21 V. Sustained input
voltages in excess of 19 V can damage the TVS diode.
Caution The 12V and SW12V terminals on the wiring panel are not regulated by
the CR3000; they are at the same voltage levels as the CR3000 primary power
supply. When using the CR3000 wiring panel to source power to other 12-Vdc
devices, be sure the power supply regulates the voltage within the range specified
by the manufacturer of the connected device.
7.4.2 Calculating Power Consumption
Read More! Power Requirements
(p. 64).
System operating time for batteries can be determined by dividing the battery
capacity (ampere-hours) by the average system current drain (amperes). The
CR3000 typically has a quiescent current draw of 0.2 mA (with display off), 0.3
mA with a 1-Hz sample rate, and 10 mA with a 100-Hz sample rate. With the
integrated keyboard / display on, an additional 1 mA is added to the current drain
while enabling the backlight for the display adds 42 mA to the current drain.
7.4.3 Power Supplies
The CR3000 is powered by an internal- or external- power supply. The appendix
Power Supplies
(p. 566)
lists power supplies available from Campbell Scientific,
including alkaline and solar options. More information is available in manual or
brochure form at www.campbellsci.com.
Options for an internal-power supply include an alkaline- and rechargeable-
battery bases. While the CR3000 has a wide operating-temperature range,
battery-base ranges are more limiting. Exceeding the specified range may
degrade battery capacity and lifetime. Battery leakage caused by too high
temperatures can result in damage to the power supply or even the CR3000.
7.4.3.1 External Batteries
When connecting external power to the CR3000, remove the green POWER IN
connector from the CR3000 face. Insert the positive 12-Vdc lead into green
connector terminal 12V. Insert the ground lead in green connector terminal G.
Re-seat the green connector into the CR3000. The CR3000 is internally protected
against reversed external-power polarity. Should this occur, correct the wire
connections.