Quick Start Guide

Quick Start Guide
D103214X012
DLC3010 Digital Level Controller
September 2014
16
Grounding
WARNING
Personal injury or property damage can result from fire or explosion caused by the discharge of static electricity when
flammable or hazardous gases are present. Connect a 14 AWG (2.1 mm
2
) ground strap between the digital level controller
and earth ground when flammable or hazardous gases are present. Refer to national and local codes and standards for
grounding requirements.
The digital level controller will operate with the current signal loop either floating or grounded. However, the extra
noise in floating systems affects many types of readout devices. If the signal appears noisy or erratic, grounding the
current signal loop at a single point may solve the problem. The best place to ground the loop is at the negative
terminal of the power supply. As an alternative, ground either side of the readout device. Do not ground the current
signal loop at more than one point.
Shielded Wire
Recommended grounding techniques for shielded wire usually call for a single grounding point for the shield. You can
either connect the shield at the power supply or to the grounding terminals, either internal or external, at the
instrument terminal box shown in figure 11.
Power/Current Loop Connections
Use ordinary copper wire of sufficient size to ensure that the voltage across the digital level controller terminals does
not go below 12.0 volts DC. Connect the current signal leads as shown in figure 9. After making connections, recheck
the polarity and correctness of connections, then turn the power on.
RTD Connections
An RTD that senses process temperatures may be connected to the digital level controller. This permits the instrument
to automatically make specific gravity corrections for temperature changes. For best results, locate the RTD as close to
the displacer as practical. For optimum EMC performance, use shielded wire no longer than 3 meters (9.8 feet) to
connect the RTD. Connect only one end of the shield. Connect the shield to either the internal ground connection in
the instrument terminal box or to the RTD thermowell. Wire the RTD to the digital level controller as follows (refer to
figure 11):
Two‐Wire RTD Connections
1. Connect a jumper wire between the RS and R1 terminals in the terminal box.
2. Connect the RTD to the R1 and R2 terminals.
Three‐Wire RTD Connections
1. Connect the 2 wires which are connected to the same end of the RTD to the RS and R1 terminals in the terminal
box. Usually these wires are the same color.
2. Connect the third wire to terminal R2. (The resistance measured between this wire and either wire connected to
terminal RS or R1 should read an equivalent resistance for the existing ambient temperature. Refer to the RTD
manufacturer's temperature to resistance conversion table.) Usually this wire is a different color from the wires
connected to the RS and R1 terminals.