Connecting devices equipped with Reed switches
Reed switches are basically designed for small contact ratings. To connect a load with
higher power consumption it is indispensable to use a contact protection relay (e.g. our
series MSR01)
If you connect directly a load to a Reed contact the following recommendations should be
considered.
None of the contact rating values printed on the switching unit must not to be exceeded,
even momentarily. This is valid for each of the given values individually: voltage, current,
power. The Reed contact integrated in the switching unit is very sensible to electrical over-
load
Danger of overload is given by the following applications:
•
inductive load
•
capacitive load
•
lamp load
Inductive Load
Inductive loads consist e.g. of relay, contactors, solenoid valves, motors, electric engines,
etc.
WARNING: Voltage spikes at shut down (up to 10 times of nominal voltage)
Protective measures: (examples)
(Flyback diode, e.g. type 1N4007)
Capacitive Load
Capacitive loads consist e.g. of long connection cables or capacitive consumers.
WARNING: High current spikes at switching on (this will exceed the nominal current)
Protective measures: (examples)
Limitation of current by a resistor
DS04 Instruction manual 03/2020
page 6