28
Wiring
(continued)
Step Five
SWITCHING INDUCTIVE LOADS
The use of suppressors (snubbers) is always recommended when switching inductive loads to prevent
disrupting the microprocessor’s operation. The suppressors also prolong the life of the relay contacts.
Suppression can be obtained with a catch diode for DC circuits and a resistor-capacitor (RC) for AC circuits.
Catch Diode
Always use stepper relays between the sensor and external loads.
For DC circuits always use a catch diode such as 1N4148, shown
on left.
Refer to the following circuits for RC network assembly and installation:
Choose R and C as follows:
R: 0.5 to 1 Ohms for each volt across the contacts
C: 0.5 to 1 μF for each amp through closed contacts
Notes:
1. Use capacitors rated for 250 VAC.
2. RC networks may affect load release time of solenoid loads. Check
to confirm proper operation.
3. Install the RC network at the meters relay screw terminals. An RC
network may also be installed across the load. Experiment for best
results.
VOLTAGE OUTPUT
LVU500 series can be configured as a 0 to 5 VDC output. A resistor will need to be added to the circuit to
enable a voltage output (refer to the wiring diagram below).
0-5 VDC output
o
Add a 250 Ohm resistor
o
Actual output will be 0.8 to 5 VDC
