Rosemount 3051S Electronic Remote Sensors - Emerson Process ...

Rosemount 3051S ERS System
2-14
Reference Manual
00809-0100-4804, Rev AA
January 2011
ERS System with Optional Remote Display and Interface (Figure 2-10
and Figure 2-11)
1. Remove the housing cover labeled “Field Terminals” on both ERS
sensors and the remote housing.
2. Using the ERS Madison Cable (if ordered) or an equivalent 4-wire
shielded assembly per the specifications detailed on page 2-14,
connect the 1, 2, A, and B terminals between the two sensors and
remote housing in a “tree” (Figure 2-10) or daisy-chain (Figure 2-11)
configuration.
3. Connect the ERS system to the control loop by wiring the “+” and “–”
PWR / COMM terminals of the remote housing to the positive and
negative leads, respectively.
4. Plug and seal all unused conduit connections.
5. If applicable, install wiring with a drip loop. Arrange the drip loops so
that the bottom is lower than the conduit connections and the
transmitter housings.
6. Reinstall and tighten all housing covers so that metal contacts metal
to meet explosion-proof requirements.
NOTE:
I.S. barriers with inductive loads greater than 1 mH should not be used with
the 3051S ERS System and may cause the device to not function properly.
ERS Cable Specifications
• Cable Type: Recommend Madison 04ZZXLF015 cable. Other
comparable cable may be used as long as it has independent dual
twisted shielded pair wires with an outer shield. The Power wires (pin
terminals 1 & 2) must be 22 AWG minimum and the communication
wires (pin terminals A & B) must be 24 AWG minimum.
• Maximum Cable Length: Up to 100 feet (30,5 meters), depending on
cable capacitance
• Cable Capacitance: The capacitance between the communication
lines as wired must be less than 5000 picofarads total. This allows up
to 50 picofarads per foot (163 picofarads / meter) for a 100 ft. cable.
• Cable Outside Diameter: 0.270 in. (6.86 mm).
4-20 mA Loop Wiring Specifications
It is recommended to use twisted pair wiring. To ensure proper
communication, use 24 AWG to 14 AWG wire, and do not exceed 5000 ft.
(1500 meters).
Surges / Transients
The ERS system will withstand electrical transients of the energy level usually
encountered in static discharges or induced switching transients. However,
high-energy transients, such as those induced in wiring from nearby lightning
strikes, can damage the ERS system.