ABB SV-1 Talimat Broşürü - Sayfa 4

Röleler ABB SV-1 için çevrimiçi göz atın veya pdf Talimat Broşürü indirin. ABB SV-1 20 sayfaları. Instantaneous current and instantaneous voltage relays

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I.L. 41-766.1N

energized. The pressure of the screen against the

indicator may be adjusted by bending the screen

between its lower end and the large elongated

hole.This pressure should be such that the indicator

will be held at any further position to which it is moved

after entering the screen opening. However, the mini-

mum amount of pressure necessary to obtain this

adjustment should not be exceeded appreciably, since

the pick-up value, and consequently the ratio, will be

affected. The purpose of this pressure is to eliminate

indicator rattle which might otherwise occur under cer-

tain energized conditions.

The moving contact leads pass through insulation

sleeves assembled on the shanks of the terminal clips

which are attached to the base terminals. These

sleeves are notched at their upper ends, and the

notches are toward the center of the relay. The leads

are bent at approximately a right angle where they pass

out through the notches, which aids in preventing them

from coming into contact with the stationary contact

brackets. Figure 1, (page 8) shows properly coiled and

assembled moving contact leads.

Although the moving contact leads are very flexible, if

the leads have been pulled out of their original shape

by handling they may exert sufficient side pressure on

the shaft bearing or twisting force against the guide

post to cause appreciable friction and wear. If this con-

dition continues for a long period of time, the resulting

wear may affect the relay calibration or the dropout ratio

noticeably. In extreme cases the wear may progress to

a degree which may occasionally cause failure of the

plunger to drop down when the relay is de-energized.

Correct shaping of the leads is not difficult, and they

may be checked readily by removing the guide post

and the nut at the top of the shaft. The plunger

should be held in the raised position, either by ener-

gizing the relay or by pressing lightly against the col-

lar under the insulation plate after raising the plunger

manually. With the plunger raised, the insulation

plate should be oscillated slightly in a horizontal

plane by twisting it horizontally and releasing it. If in

several trials the plate comes to rest with the center

line of the contacts approximately parallel to the

base and with its mounting hole fairly well centered

with the end of the shaft, if the plate does not tip

appreciably, and if the leads have a safe clearance

to the stationary contact brackets, the leads are

SC, SC-1, SV and SV-1 Relay

properly shaped.

If this check shows that re-shaping is necessary, it

may be possible to obtain sufficient correction by

bending the leads sharply where they emerge from

the insulation sleeves. One or two pairs of tweezers

are tools for re-shaping the leads. If it is necessary

to re-coil the leads, they should be wound around a

rod having a diameter of approximately 5/32". The

coils then should be stretched out just enough to

avoid side pull or twisting force on the plunger

assembly.

In all relays except the SV-1 relay for ac, if the sta-

tionary contacts are assembled so that they close

when the relay is energized, they should be located

so that they barely touch the moving contacts when

the latter are 5/32" above the de-energized position.

The moving contacts can be held in this position

while the adjustment is being made by inserting a 5/32"

spacer between the shaft collar and the top of the

core. This dimension should be 3/16" on the SV-1

relay for ac. Both contacts should touch at the same

time when the plunger is raised. When the plunger is

moved upward against its stop, there should be a

slight deflection of the stationary contact stop

springs, but this should not exceed 1/32". When the

stationary contacts are reversed so that they are

closed when the relay is de-energized, they should

be located so that they just touch the moving con-

tacts when the latter are 1/32" above the de-ener-

gized position. On some relays it may be found that

when the contacts are used in this position the relay

may operate at values a few percent below the scale

markings. The adjustments specified for the station-

ary contacts are important. Failure to observe them

may cause improper relay operation, either directly

or after a period of service. Contact position should

not be used as a means of altering the ratio of drop-

out to pickup.

5.0 RENEWAL PARTS

Repair work can be done most satisfactorily at the

factory. However, interchangeable parts can be fur-

nished to the customers who are equipped for doing

repair work. When ordering parts, always give the

complete nameplate data.