Basler Electric BE3-49R - 3 Inputs Temperature Relay

INTRODUCTION

Three-input BE3 temperature relays use resistance

temperature detectors (RTDs) to monitor remote

temperatures. When any of three monitored temperatures

exceeds a preset limit, the corresponding relay output

operates. A dc metering output indicates the highest

temperature of the three RTDs. BE3 temperature relays are

available for use with 10 Ω copper or 100 Ω platinum RTDs.

OPERATION

Three temperatures are monitored through RTDs connected

at the nine-position front panel connector. RTD connections

are labeled A, B, and C. Three user-adjustable controls are

located on the front panel: SET 1. SET 2. and SET 3. Each

setpoint is adjustable from 50 to 100% (±3%) of the RTD

temperature range. When a setpoint is exceeded, the

corresponding TRIP LED lights and the relay output

energizes. Each RTD has a corresponding LED to identify

which RTD has exceeded the temperature setpoint. For

example, if the temperature of RTDs B and C exceeds the

trip level, the B and C TRIP LEDs light and the relay output

energizes. A green LED labeled AUX indicates the power

supply status. Figure 1 illustrates the BE3-49R controls,

indicators, and terminals.

INSTALLATION

BE3 temperature relays are designed for mounting on

standard DIN rails that comply with DIN-EN 50022.

Mounting involves hooking the top edge of the cutout on the

base of the case over one edge of the DIN rail. The opposite

side of the cutout containing the release clip is then pushed

over the opposite side of the DIN rail. To remove or

reposition the relay, lever the release clip and move the

relay as required. BE3 relays should be installed in a dry,

vibration-free location where the ambient temperature does

not exceed the operating temperature range. Connections to

the relay should be made using wire that meets applicable

codes and is properly sized for the application. Figure 2

illustrates the terminal connections for the BE3-49R

temperature relay.

A burden resistor must be installed across all unused RTD

inputs that are not connected to an actual RTD. For units

with style number 5HXXX, it is suggested that a 10 Ω

resistor be connected across any unused RTD inputs. For

units with style number 5IXXX, it is suggested that a 100 Ω

resistor be connected across any unused RTD inputs. The

minimum power rating for the burden resistors is ¼ W.