Electrical Connections; Power Supply - Fisher FIELDVUE DLC3010 Instruction Manual

Installation
October 2014

Electrical Connections

WARNING
Select wiring and/or cable glands that are rated for the environment of use (such as hazardous area, ingress protection and
temperature). Failure to use properly rated wiring and/or cable glands can result in personal injury or property damage
from fire or explosion.
Wiring connections must be in accordance with local, regional, and national codes for any given hazardous area approval.
Failure to follow the local, regional, and national codes could result in personal injury or property damage from fire or
explosion.
Proper electrical installation is necessary to prevent errors due to electrical noise. A resistance between 230 and 1100
ohms must be present in the loop for communication with a Field Communicator. Refer to figure 2‐9 for current loop
connections.
Figure 2‐9. Connecting a Field Communicator to the Digital Level Controller Loop
NOTE:
1 THIS REPRESENTS THE TOTAL SERIES LOOP RESISTANCE.
E0363

Power Supply

To communicate with the digital level controller, you need a 17.75 volt DC minimum power supply. The power
supplied to the transmitter terminals is determined by the available supply voltage minus the product of the total loop
resistance and the loop current. The available supply voltage should not drop below the lift‐off voltage. (The lift‐off
voltage is the minimum "available supply voltage" required for a given total loop resistance). Refer to figure 2‐10 to
20
230 W 3 R 3 1100 W
1
L
Reference meter
+ for calibration
or monitoring
operation. May
be a voltmeter
across 250 ohm
−
resistor or a
current meter.
A Field Communicator
may be connected at any
termination point in the signal
loop. Signal loop must have
between 250 and 1100 ohms
load for communication.
Instruction Manual
− +
+ −
Signal loop may be grounded at
any point or left ungrounded.
D102748X012
+
POWER
SUPPLY
−