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Replacement Strategy
Relay Life Factors
End-of-Life Determination
Appendix B
Electromechanical relays are subject to normal wear-out. Relay life depends
on several factors as shown below. The recommended repair strategy for the
E8482A/B RF Multiplexer modules is PCA-level replacement. User repairs
to the E8482A/B RF Multiplexer modules are limited to replacement of the
entire circuit board (P/N E8482-60001) when any of the relay fails or the end
of relay life approaches. The sensitivity of the application should be weighed
against the cost of replacing the entire circuit board with some useful life
remaining. For more information, contact Agilent Technologies (see
page 10).
NOTE
Relays that wear out normally or fail due to misuse should not be
considered defective and are not covered by the product's warranty.
Some effects of loading and switching frequency on relay life follow.
•
Relay Load. In general, higher power switching reduces relay life. In
addition, capacitive/inductive loads and high inrush currents (for
example, turning on a lamp or starting a motor) reduces relay life.
Exceeding specified maximum inputs can cause catastrophic failure.
•
Switching Frequency. Relay contacts heat up when switched. As the
switching frequency increases, the contacts have less time to dissipate
heat. The resulting increase in contact temperature also reduces relay
life.
A preventive maintenance routine can prevent problems caused by
unexpected relay failure. The end of the life of the relay can be determined
by using one or more of the three methods described below. The best method
(or combination of methods), as well as the failure criteria, depends on the
application in which the relay is used.
•
Contact Resistance Maximum Value. As the relay begins to wear
out, its contact resistance increases. When the resistance exceeds a
predetermined value, the relay should be replaced.
Appendix B
Relay Life
Relay Life
39
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