710 Relays & Timers

1 and 7

If a relay with the contact arrangement shown in the figure was not energized, which contacts would be made up?

Making Contacts

What are normally open (NO) contacts commonly referred to as?

By energizing the reset winding.

How are magnetic set/reset relays that use a reset coil reset?

Mechanically

How do latching relays remain set (held)?

Add a diode in parallel with the coil.

How would you delay a relay from dropping out immediately?

25V

A capacitor in a circuit has a source voltage of 25V. What will be the capacitor voltage when fully charged?

It adjusts the off-delay time for Relay 1

Refer to the figure. What role does the variable resistor play in the circuit?

Capacitor C1 would not discharge properly.

Refer to the figure. What would happen in the circuit if contact A1-2 failed?

Shorted Coil

Testing with a multimeter, low voltage is read directly across the door close relay coil, and the resistor that is in series with it is hot. The coil, however, will not pull in. Which of the following is most likely the problem?

Shading Coil

What is used to stop the hum or chatter of AC relays?

Provides on-delay timing for the relay.

What purpose does C1, R1, and R2 serve for the circuit shown in the figure?

An 8-second timer, with normally opened contacts and a 12-volt coil.

What would the data 12 N.O. 8, printed on the side of a bi-metallic indicate?

Tracing Self-Holding Contact

When working on a relay without legible prints, what are good clues to finding contact numbers?

The maximum voltage to the coil.

Which of the following best describes the coil rating of a magnetic switch?

Set/Reset Relays

Which of the following is a memory style relay?

Capacitor Leaking

Which of the following is a reason for capacitor failure?

Leave the circuit in the failed state for troubleshooting.

Which of the following steps would be most appropriate when arriving on a trouble call for a relay logic controller?

To reduce contact arcing.

While troubleshooting a controller, you notice a relay with two contacts wired in series. Why was this done?