GE IRT51 E, Инструкция по эксплуатации, Страница: 15 / 51

GEK-86038
1. The relay senses a temperatu re at or below the pre-selected reset
temperatu re , causing the right-hand contact (IRTR) to close , and
2. The relay is reset by any one of the three methods listed below:.
METHOD 1:
Reset can be accompli shed by pushing u pward on the reset rod
1
ocated at the
bottom , left side of the relay cover.
METHOD 2:
Reset can be accomplished electrically from a remote location by connecting a
switch across terminals 1 9 and 20. When the switch is closed , the relay will
reset; however , the target of the target seal-in unit will still show if the
target seal-in unit had operated. The only way to remove the tar get indication
is by manually pushing u pward on the reset rod located at the bottom , left side
of the relay cover.
METHOD 3:
The relay can be made to be self-resetting by shorting terminal s 19 and 20
to gether. If this method of resetting is chosen , the tar get of the target
seal-in unit will still show if the tar get seal-in unit had o perated. The only
way to remove the target indication is by manually pushing u pward on the reset
rod located at the bottom , left side of the relay cove r.
The IRT5 1 G and IRT51H auxiliary circuits have a special inte rlock arran gement
that will maintain the last energized position of the contacts. This position will
be maintained even if power is removed from the relay. This s pecial featu re must be
considered when first placing the relay into service or when retu rning a relay back
into service after completing maintenance on the relay. To avoid tripping on start
up for reasons other than overtemperatu re:
1. Apply power to the IRT relay
2 .
Reset the I RT relay manually
3 . Energize the equipment which is to be protected.
This will ensu re that the relay contacts and target seal-in unit are in the correct
state for ove rtemperatu re protection.
,�
RTD CONNECTIONS
Each of the IRT relays has been designed to be used with a specific type
resistance temperature detector. Before connecting an RTD to the relay , make sure
that the re 1 ay is suitable for use with the RTD. This information is presented on
the relay name plate , and in Table 1 of this instruction book.
The RT Ds to be used with IRT relays should be a three wi re type. The leads
coming from the RTDs should be shielded to prevent stray fields from inducing
voltages into the RTD circuit. If an extension to the RTD length is required, the
extension leads should be twisted to gether. Also , the lead extension resistance
1 3
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