FlowLine DataView LI55 Series Quick Start Manual page 11

DataView™ LI55 Level Controller
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Switching Inductive Loads
When switching inductive loads, suppressors or snubbers should always be
employed as they prevent microprocessor disruption and 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. This
section is provided to assist you with suppressor assembly and installation.
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
When using suppressors:
Use capacitors rated for 250 VAC.
1.
Confirm proper relay operation. RC networks may affect load release
2.
time of solenoid loads.
Install the RC network on the DataView's relay screw terminals. An
3.
RC network may also be installed across the load.
Use a diode with a reverse breakdown voltage that's 2-3 times the circuit
4.
voltage and forward current at least as large as the load current.
Note: Relays are de-rated to 1/14th HP (50 watts) with an inductive load.
QS301033 Rev C1
C
R
C
R
Quick Start
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