what is the difference between the 94 lockout relay and 86
lock out relay. I have noticed that the 94 lockout relay is
activated when the distance realy is activated and 86 is
activated when the 87T differential is activated. but why
can't the same lockouts be used for both the protection
schemes

Answers were Sorted based on User's Feedback



what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / syed furqan akhter

94 relay shall not be called out the lockout relay.It is
basically a self reset relay.Its contacts operate till the
fault persist or its coil energizes and when its de-
energizeits contact reach its normal position. Its usage is
where Autoreclosing is required to close the Circuit
breaker whenever temporary fault occurs.Therefore in
overhead lines this relay (94)is used.

While 86 relay is a lockout relay means once its coil
enrgizes its contact will be operated and will never come
its normal position until it is reset by hand or
electrically. Therefore it is used where permenant faults
occurs and no autoreclosing scheme is posible.

Is This Answer Correct ?    35 Yes 1 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / gtmanikandan

86 lock out relay is hand reset used for mechanical
protection (permanent fault) & 94 lockout relay is self
reset used for tranisent fault (temprovery fault condition)
this is major different between 86 and 96 lockout relay

Is This Answer Correct ?    39 Yes 21 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / jayesh n. pillai

86 LOCK OUT RELAY IS AN ELECTRICALLY OPERATED HAND, OR
LECTRICALLY RESET RELAY OR DEVICE THAT FUNCTIONS TOSHUT DWN
OR HOLD AN EQUIPMENT OUT OF SERVICE, OR BOTH, UPON THE
OCCURRENCE OF ABNORMAL CONDITIONS.

94TRIPPIN RELAY IS HAVING FUNCTION TO TRIP A CIRCUIT
BREAKER, CONTACTOR OR EQUIPMENT, OR TO PERMIT IMMEDIATE
TRIPPING BY OTHER DEVICES. OR TO PREVENT IMMEDIATE
RECLOSURE OF ACIRCUIT INTRRUPTER IF IT SHOULD OPEN
AUTOMATICALLY EVEN THOUGH ITS CLOSING CIRCUIT IS MAINTAINED
CLOSED.

Is This Answer Correct ?    18 Yes 3 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / bilal din

94 is ANSI code for tripping relay and 86 is ANSI code of
Louck out relay.
Both have specific fuction and can not be interchangable,
means we can not use lockout relay for trip fucntion and
vice versa,...

Is This Answer Correct ?    5 Yes 0 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / ayman elwardani

86 Lockout relays are used by many utilities in electrical
power transmission substations to trip and hold out of
equipment service within a protected zone on the occurrence
of protection relay operation which requires inspection
and/or repair before the zone may be safely placed back in
service. The original intent of lockout was that on
operation, maintenance or operating personnel would inspect
and repair as required the locked-out zone, and when clear,
would reset the lockout allowing operators to place the
element back in service. However in recent decades, it has
become normal to remotely control substations, resulting in
the absence of on-site personnel to reset a lockout in an
emergency situation
On the other hand, 94 inter-trip relay is used for up or
down stream backup protection to prevent the other side
breaker from supplying the faulty zone. The inter-trip
signal shall be cleared as the fault cleared and associated
relay has been reset.

Is This Answer Correct ?    4 Yes 1 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / sachidananda pal

86 is actually an Electrically/Hand reset Master trip relay
that trips both the primary & Secondary of a Transformer
whereas 94 is a lockout relay that is used in transmission
line protection eg. in an Auto recloser.In case of a fault
the Autorecloser shall start it's O-t-CO-T-CO-T-CO-T-CO
operation. After un successfuly trying to reclose the line,
the 94 Lockout relay shall act afetr the time duration set
& will put the Autorecloser in an Lockout condition so that
there are no further reclosing attempts.

Is This Answer Correct ?    3 Yes 2 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / venkatesan

86 lockout relay is a high speed tripping relay which is used to block close and trip the circuit breaker in the event of fault signal received from protective relays.

94 is an interposing relay which is used for high current drive application. Example: A Open or close signal from plc. The PLC output contact is designed for low current drive. To prevent PLC damage we normally use interposing relay.

Is This Answer Correct ?    2 Yes 1 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / yaldilip

94 is self reset relay trip relay
86 is lockout relay having two coils trip coil and reset coil once the trip come the trip coil will energize and plug will down once the reset coil energize and the fault will clear tan reset coil will energize and the trip coil will drop.

Is This Answer Correct ?    0 Yes 1 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / ajay khandait.

Lockout relay is handreset relay in this case both the
relays are hand reset relay. only difference is that 94
lockout relay is used for line protection and can also be
provided with auto reclosing facility.
If the auto reclosing is not successful then in that case
94 goes to Lockout state and shall be manually resetted.


In case of 86 there is no Auto reclosing feature available.
It goes to lockout state directly.

Is This Answer Correct ?    2 Yes 5 No

what is the difference between the 94 lockout relay and 86 lock out relay. I have noticed that the..

Answer / k.prakashchandra

94 lockout relay is for line fault only. 86 lockout relay
is master trip relay. It trips both primry and secondary of
the transformer as the fault is of serious nature.

Is This Answer Correct ?    2 Yes 12 No

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