Rosemount 752, Reference Manual

Page: 13 / 60

Reference Manual
00809-0100-4377, Rev BA
September 2010
2-3
Rosemount 752
Connect Wiring and
Power Up
Wiring for fieldbus protocol
1. Remove the housing cover on terminal compartment side. Do not
remove the cover in explosive atmospheres when the circuit is live.
Signal wiring supplies all power to the indicator.
2. Connect the power leads to the terminals marked “FIELDBUS WIRING”
as shown in Figure 2-2. The power terminals are not polarity sensitive.
3. Plug and seal unused conduit connections on the indicator housing to
avoid moisture accumulation in the terminal side. If you do not seal
unused connections, mount the indicator with the electrical housing
positioned downward for drainage. Install wiring with a drip loop. Arrange
the drip loop so the bottom is lower than the conduit connections and the
indicator housing.
NOTE
Do not apply high voltage (e.g. ac line voltage) to the indicator terminals.
Abnormally high voltage can damage the unit. (Indicator power terminals are
rated to 32 V dc).
Figure 2-2. Fieldbus terminal
block
Electrical Considerations
Proper electrical installation is necessary to prevent errors due to improper
grounding and electrical noise. Shielded, twisted pair cable should be
used for best results in electrically noisy environments. Cable Type A is
recommended by F
OUNDATION
®
fieldbus.
Power Supply
The indicator requires between 9 and 32 V dc (9 and 15 V dc for FISCO) to
operate and provide complete functionality. The dc power supply should
provide power with less than 2% ripple.
Power Conditioner
A fieldbus segment requires a power conditioner to isolate the power
supply filter and decouple the segment from other segments attached to
the same power supply.
Grounding
Signal wiring of the fieldbus segment can not be grounded. Grounding out
one of the signal wires will shut down the entire fieldbus segment.
See “Safety Messages” on page 2-1 for complete warning information.