LI5X Process & Temperature Meter Instruction Manual
20
Switching Inductive Loads
The use of suppressors (snubbers) is strongly recommended when switching
inductive loads to prevent disrupting the microprocessor’s operation. The sup-
pressors also prolong the life of the relay contacts. Suppression can be obtained
with resistor-capacitor (RC) networks assembled by the user or purchased as
complete assemblies. Refer to the following circuits for RC network assembly
and installation:
Figure 12. AC and DC Loads Protection
Choose R and C as follows:
R: 0.5 to 1
Ω
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 con-
firm proper operation.
3.
Install the RC network at the meter's relay screw terminals. An RC network
may also be installed across the load. Experiment for best results.
Figure 13. Low Voltage DC Loads Protection
Use a diode with a reverse
breakdown voltage two to
three times the circuit volt-
age and forward current at
least as large as the load
current.
Spec Tech Industrial Electric
www.spectechind.com
888-773-2832
Spec Tech Industrial Electric
www.spectechind.com
888-773-2832