Troubleshooting Relays and Switches Flashcards
If a sealed relay fails, how is it repaired?
If a sealed relay fails, all you can do is replace it.
What are the two common relay failures?
Faulted magnetic coils
Faulted contacts
A faulted core either ____ or _____. In either case, coil windings cannot be repaired.
A faulted core either opens or shorts. In either case, coil windings cannot be repaired.
An open coil will measure ______. A shorted coil will measure ______ ohms.
An open coil will measure infinity. A shorted coil will measure 0 ohms.
Current flowing through a relay’s contacts in one direction can only cause what type of failure?
Coned and Cratered
What type of tool should you use to clean contacts in relays?
Burnishing Tool
The first step in checking a relay is to _______.
check inputs
When the input voltages or signals are NOT correct, check the _______.
preceding circuit
Is the relay operating correctly?
No, the relay is not de-energized.
Is the relay operating correctly?
Yes
Is the relay operating correctly?
No, the relay is not energized.
The two most common faults in a relay are _______.
faults in the coil and contacts
Is the relay operating correctly?
Yes, but the energizing voltage is not present.
Normally, when the relay is energized, -15 V is present on the output contact. This time, the relay is energized, but 0 V is present on the output contact. What is the possible fault?
Input 2 voltage is incorrect.
Is the relay operating correctly?
No, the relay is not energized.
