Crystal WT Series Panel Mount Digital Pressure Gauge - Manual (Page 3)

Overview  3
XP2i External Power Supply Operation Manual
Overview
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IntroductIon
Although the XP2i was designed to operate for many hours on a set of 3 AA size batteries, there are times when even this may not be sufficient.
For example, if your XP2i is mounted in a test stand, bench or panel, the battery access cover may be inconvenient, or even difficult to reach.
To address these situations, Crystal Engineering has designed an external power supply that can be operated from virtually any available standard AC line
supply.
This External Power Supply kit is rated for AC line voltages from 90 to 264 VAC, and 47 to 63 Hz. The kit includes 4 interchangeable AC line plugs that snap
onto the power supply. With this assortment you should find a plug compatible with the AC line receptacles used in your country, so you can put this kit to im-
mediate use.
To minimize penetrations into the XP2i, which could increase the chances of water intrusion, there is only one external (fully sealed) electrical connection on
the exterior of the gauge: The DB-9 serial connector. The ground return and one of the (unused) RS-232 pins is used to power the gauge. This is not a direct
connection to the battery: Circuitry isolates the battery, and when sufficient voltage is applied (9VDC), the externally applied voltage forces the XP2i to switch
from battery power to external power. The external supply will not charge the batteries. Instead, the batteries become an uninterruptible power supply, and
should the AC line power fail, the circuitry will automatically revert to operation from the batteries.
The connection to the XP2i is a double DB-9 pass through design, which permits you to use the RS-232 interface even when using the external power supply.
Crystal Engineering is the company that designs, manufactures, markets, and services the nVision reference recorder, XP2i digital test gauge, 30 series pressure
calibrators, MultiCal multimeter pressure adapters, and a variety of industry specific pressure measuring equipment. Crystal Engineering pioneered features like
full temperature compensation and “of reading” rated gauges and calibrators. Pressure measuring equipment is the only thing we do and that’s why we say:
™