1. Rosemount 3051S ERS System Composition
The Rosemount 3051S ERS system is a flexible 2-wire HART architecture consisting of two sensors, one designated as the "primary" and the other as the "backup." The pressure sensors are interconnected and synchronized via cables to form a single Rosemount ERS system. The sensors used in the Rosemount ERS system can include any combination of Rosemount 3051SAM and 3051SAL models.
2. Rosemount 3051S ERS System Overview
The ERS system calculates the differential pressure (DP) by subtracting the pressure measurement from the PLO transmitter's pressure measurement from the PHI transmitter's pressure measurement.
The transmitters are pre-configured at the factory. The primary sensor (4–20 loop terminals and optional LCD display) is designated as a PHI device, and the backup sensor (junction box housing) is designated as a PLO device. In installations where the primary transmitter is mounted on a PLO process connection (e.g., on top of a tank), these specifications allow for electronic switching of the communication device.
3. Rosemount 3051S ERS System Installation
3.1 Identifying Rosemount ERS Sensors
A complete ERS system comprises two pressure sensors, one mounted on the high-pressure (PHI) process connection and the other on the low-pressure (PLO) process connection. Refer to the wire-fixed label on the 3051S ERS transmitter to determine whether it is configured as a PHI or PLO sensor.
The Rosemount 3051S ERS transmitter is pre-configured at the factory. The primary device (4–20 loop terminals and optional LCD display) is designated as a PHI sensor, and the backup device (junction box housing) is designated as a PLO sensor. In installations where the primary transmitter is mounted on a PLO process connection (e.g., on top of a tank), these specifications allow for electronic switching of the communication device.
3.2 Installation of Each Sensor
Install the PHI and PLO sensors on the appropriate process connection for the specific application.
Vertical Installation
In vertical installations, such as in vessels or distillation columns, the PHI sensor is installed on the bottom process connection. The PLO sensor is installed on the top process connection.
Horizontal Installation
In horizontal installations, the PHI sensor is installed on the upstream process connection. The PLO sensor is installed downstream.