Considerations - Emerson Rosemount 848T Reference Manual

Reference Manual
00809-0100-4848
WARNING
Electrical shock could cause death or serious injury.
Use extreme caution when making contact with the leads and terminals.
The power module with the wireless unit contains two "C" size cells. Each of the primary
lithium/thionyl chloride battery contains approximately 2.5 grams of lithium, for a total of
5 grams in each power module. Under normal conditions, the battery materials are self-
contained and are not reactive as long as the batteries and the module integrity are
maintained. Care should be taken to prevent thermal, electrical or mechanical damage.
Contacts should be protected to prevent premature discharge.
Battery hazards remain when cells are discharged.
Power modules should be stored in a clean and dry area. For maximum life, storage
temperature should not exceed 30 °C.
1.3

Considerations

1.3.1 General
Electrical temperature sensors such as RTDs and thermocouples produce low-level signals
proportional to their sensed temperature. The Rosemount 848T converts this signal into a
robust WirelessHART
1.3.2 Commissioning
The transmitter can be commissioned before or after installation. It may be useful to
commission it on the bench, before installation, to ensure proper operation and to
become familiar with its functionality. When applicable, make sure the instruments are
installed in accordance with intrinsically safe or non-incendive field wiring practices. The
device will be powered whenever the power module is installed. To avoid depleting the
power module, make sure it is removed when the device is not in use.
1.3.3 Mechanical
Location
When choosing an installation location and position, take into account the need for access
to the transmitter. For best performance, the antenna should be vertical with the conduit
entries facing downward. The antenna should have space between objects in a parallel
metal plane, such as pipes or metal framework, as they may adversely affect the
performance of the antenna. Place the antenna 18–36 in. (0.46–0.91 m) from any solid
metal surface, building, or structure.
Note
The antenna can only rotate backwards.
Emerson.com/Rosemount
®
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Introduction
September 2019
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