Instruction Leaflet
41-579.11B
Effective: January 1, 2012
Supersedes I.L. 41-579.11, Dated May 2004
( ) Denotes Text Change Since Previous Issue
( * ) Denotes Figure Change Since Previous Issue
Type TD-5
Time Delay Relay
All possible contingencies which may arise during installation, operation or maintenance, and all details and
variations of this equipment do not purport to be covered by these instructions. If further information is desired by
purchaser regarding this particular installation, operation or maintenance of this equipment, the local ABB
representative should be contacted.
(for Class 1E application)
Before putting relays into service, remove all
blocking inserted for the purpose of securing the
parts during shipment. Make sure that all moving
parts operate freely. Inspect the contacts to see
that they are clean and can close properly. Close
the red handle switch last when placing the relay
in service. Open the red handle first when
removing relay from service.
CONTENTS
This instruction leaflet applies to Class 1E TD-5 Time
Delay Relays which can be described as follows:
TD-5 Time Delay Relays with Smart Style Number
Ex: TD51ET1V1PNN
1.0 APPLICATION
This relay has been specially designed and tested to
establish its suitability for Class 1E applications in
accordance with the ABB Relay Division program for
Class 1E Qualification Testing as detailed in the ABB
publication STR-1.
“Class 1E” is the safety classification of the electric
equipment and systems in nuclear power generating
stations that are essential to emergency shutdown of
the reactor, containment isolation, cooling of the reactor,
Printed in U.S.A.
and heat removal from the containment and reactor, or
otherwise are essential in preventing significant release
of radioactive material to the environment.
The type TD-5 relay is used in timing applications where
accuracy, repeatability and fast reset are required. Its
principal use is in time delayed distance relaying and in
breaker failure timing applications.
TD-5 is a dc relay capable of direct application to station
batteries. It covers 0.05 to 30 seconds in 4 different
ranges.
2.0 CONSTRUCTION AND OPERATION
The type TD-5 relay consists of a reference voltage circuit,
a rheostat (T) and scale plate, a voltage biasing
potentiometer or adjustable resistor (P), a printed circuit
board containing static timing components; an output
relay (TR), and an indicating contactor switch (ICS). An
auxiliary relay (TX) is supplied on some TD-5 relays to
override bounce of the initiating contact.
TR and TX are printed circuit board mounted miniature
power relays.
