Precision Digital PD663 - Manual (Page 15)

PD663 Loop-Powered Meter Instruction Manual
15
4-20 mA Input Connections & Wiring Diagrams
Signal input connections are made to a three-terminal connector labeled S+|S-|X
for models without a backlight and S+|S-|B- for models with a backlight. The
enclosure also provides one internal and one external earth grounding screw.
The 4-20 mA input with no backlight has a maximum voltage drop of 1.7 V and is
wired as shown in Figure 2. The loop-powered backlight configuration requires a
total maximum voltage drop of 4.7 V. The backlight is recommended for dim
lighting conditions and is enabled when wired as shown in Figure 3. The
enclosure also provides one internal and one external earth grounding screw.
Figure 2. PD663 Input Connections without Backlight
Figure 3. PD663 Input Connections with Backlight
S+ S- B-
4-20 mA
Transmitter
Power
Supply
S+ S- X
4-20 mA
Transmitter
Power
Supply