What is relay timer?


#1

Relay Timers

Timing relay has device that delays the immediate activation or deactivation of the armature when power is applied to or removed from the relay (or both)

Older units used pneumatic/fluid cylinder or motor/gear arrangements.

New styles uses electronics,R/C network to generate delay.

Timing relay contacts are -

a)Specified by style of contact
-Normally open
-Or Normally closed

b)Specified by delay operation
-timed closing
-Timed opening

timer relay - types and categories

NOTC (Normally Open,Timed Close)

The direction of the contacts motion is identical to regular NO contact,but there is a delay in closing contact.

Contacts are open before coil is energized,timing occurs when coil is energized.

This type of contact is alternatively known as a normally-open,on-delay.

NOTO (Normally Open,Timed-Open)

This type of contact is normally open when the coil is de-energized and closed by the application of power to the relay coil.

The timing action occurs upon de-energization of coil rather than upon energization.

Alternatively known as a normally-open,off-delay

NCTO (Normally closed,Timed Open)

Contact is normally closed when the coil is de-energized.

Contact is opened after the coil has been continuously powered for the specified amount of time.

Alternatively known as a normally-closed,on-delay.

NCTC (Normally Closed,Timed-Closed)

Contact is normally closed before the coil is energized,and opened by the application of power to the relay coil.

The timing action occurs upon de-energization of the coil.

Alternatively known as a normally-closed,off-delay.