G E H-1 8 1 4
CONTACT CLEANING
For clea n i n g fine silver contacts, a flexi ble burn ishing tool should be used . Th is consists of a
flexi ble strip of metal with an etch-roughened su rface, resembl ing i n effect a su perfi n e fi le.
The polish i ng action is so delicate that no scratches are left, yet corroded mate rial will be
removed ra pidly and thoroug h ly. The flexi bil ity of the tool ensu res the clea n i n g of the
actual poi nts of contact; someti mes an ord i na ry fi le ca nnot reach the actua l poi nts of
contact because of obstruction from some other part of the relay.
Fine si lver contacts should not be cleaned with knives, fi les or abrasive paper or cloth .
Kn ives or files may leave scratches that increase
and deterioration of the contacts.
Abrasive paper or cloth may leave m i n ute particles
i nsu lati ng abrasive material i n the
contracts, and thus prevent closi ng.
The b u rnish i ng tool descri bed above can be obtained from factory.
SERVICING AN D ADJUSTM ENTS
TAR G ET AND SEAL-IN U N IT
For tri p coi ls operati ng on cu rrents ran g i ng from 0.2 u p to 2.0 amperes at the m i n i m u m
control voltage, set the target and seal-in tap plug i n the 0.2-ampere ta p.
For tri p coils operati ng on cu rrents ranging from 2.0 up to 30 amperes at the m i n i m u m
contro l voltage, place the target and seal-in tap plug in the 2.0-ampere tap.
The tap
is the screw hold i n g the rig ht-hand stationary contact of the seal-in element.
To change
tap setti ng, fi rst remove the connecti ng plug. Then, ta ke a screw from the
left-hand stationary contact and place it i n the desi red tap. Next, remove the screw from
the other, undesired, ta p, and place it i n the left-hand contact. Th is proced u re is necessa ry
to prevent the rig ht-hand stationary contact from getti ng out of adj u stme nt. Screws
should
not
be i n
both
taps at the same time, as pickup for d i rect cu rrent (DC) wi l l be the
h i g her tap val ue, and AC pickup wi ll be i ncreased .
VO LTA G E SETTI NG
The voltage at wh ich the contacts operate may be changed by cha n g i n g the position of the
ta p p l u g i n the tap block at the top of relays such as the IAV5 1 A, IAV52A, IAV53A, IAV53 B,
IAV53D, IAV53 K, IAV5 3 L,and IAV53N which have ta p ped co i l s. The ra n g e o f t h i s
adjustment i s from 55 to 1 40 volts o n the 1 1 5 volt ratings, 7 0 to 1 40 volts on the 1 99 volt
rati ngs, 1 1 0 to 280 volts on the 208, 230 and 240 volt rati ngs, and 220 to 560 volts on the
460 volt rati ngs.
The picku p of the relay for any voltage tap is adj usted by means of a spri ng-adj usti n g
ri ng (see Fig ure 1 5). The ring may be tu rned by inserting a tool i n the notches a ro u nd the
edge. By tu rn i ng the ring, the operating voltage of the relay may be bro u g ht i nto
a g reement with the ta p setting employed if, for some reason, th is adj ustment has been
d istu rbed . The adj ustment also permits any desi red setting between the va rious taps. The
relay is adj usted at the factory to operate from any time-d ial positions at a m i n i m u m
voltage with i n five percent (5%) of the tap setti ng for the relays with the tap ped coi ls,
mentioned above. The relays reset at 90% or more of the operati ng va l u e on a l l the
overvoltage relays. Operati ng voltage for the overvoltage relays for a g iven ta p setting is
the m i n i m u m voltage at which the contacts j ust make.
1 2
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