Emerson Rosemount Apex User Manual

Reference Manual
00809-0100-4731, Rev FA
April 2003
APEX
™
and APEX Sentry
™
Radar Gauge
2-32
3- or 4-Wire RTD
(APEX Radar Gauge
Only)
If your vessel is equipped with a 3- or 4-wire platinum 100 ohm RTD, wire the
gauge as shown in Figure 2-25. Make a direct connection from the RTD to the
gauge. The RTD may be mounted a maximum of 500 feet from the gauge.
1. Make sure the main power to the gauge is off and the lines to any other
external power source are disconnected or not powered while wiring the
gauge.
2. Connect three RTD wires directly from the temperature element to the
gauge. Avoid contact with leads and terminals.
3. Wire the sensor across the gauge terminals A and B and the
loop compensation across B and C.
Wires B and C are the same color code; wire A is a different color code.
When using a 4-wire RTD, one wire (the same color as the wire
connected to terminal A) is not used.
For more information about Rosemount RTDs, refer to Product Data Sheet
No. 00813-0100-2654: Series 58C, 68, 68Q, and 78 Temperature Sensors,
Assemblies, and Accessories.
NOTE
If RTD input is to be used, the gauge must have the RTD function enabled.
This can be done at the factory, or it can be done in the field using a Model
275 Hart Communicator or Radar Configuration Tool (see page 3-18).
NOTE
To ensure long life for your radar gauge, and to comply with hazardous
location installation requirements, tighten covers on both sides of the
electronics housing to achieve metal-to-metal contact.
Figure 2-25. Wire Connections
for a 3- and 4-wire RTD
Refer to Safety Messages on page 2-2 for more information.
VDC
18-35
LEVEL-0036
4 Wire RTD
WhiteWhiteRedRed
Leave unconnected from circuit
and ground and insulate
Red
A
B
C
White
White
3 Wire RTD

Emerson Rosemount Apex Specifications

General

Brand	Emerson
Model	Rosemount Apex
Category	Measuring Instruments
Language	English