Time-Overcurrent Unit; Time Setting 1 - GE IAC Series Instruction Booklet

s i g n i f ica n t l y a f f ec t e d
wa v e f orms.
There fore, i n order to test AC relays properly i t i s essent i al to
use a test voltage a nd/or current wave form that
pur i ty o f the s i n e wa ve
expressed as a f i nite
relay us i ng tuned
e l ectromagnets (such as time -overcurrent relays)
a f f ected by non -sinuso i dal wave forms.
T IME-OVERCURRENT UNIT
Rotate the time d i a l s lowly and check,
c i rcu i t, that the
sett i ng.
The po i nt at
run n i ng th e stationary
adjusti ng screw.
With the contacts
should be su f f i c i e nt gap between the stati onary contact brush a nd i ts
meta l back i ng strip to e nsure approximately 1 /32" w ipe.
The m i n i mum
determ i ned by the pos it i on of
top o f the relay.
Whe n chang i ng the current sett i ng of the relay wh i l e i n the case,
remo v e t h e connect i o n
secondary c i rcu it.
f or the desired curre nt, a n d then rep lace t h e connect i on plug.
The p i ckup of th e un i t for any curre nt tap sett i ng i s adjusted by
m e a ns of a spr i ng- adjust i ng r i ng
turn e d by i nserting
By turning the r i ng, the operat i ng current of the u n i t may be brought
i nto agre eme nt
this adjustment has be e n d i sturbed.
d e s i red sett i ng
obta i ned. The unit is adjusted at the factory to close
f rom a ny time-dia l
tap-plug sett i ng.
value.
T i me Sett i ng
The sett i ng
unit requires to
pre d etermined value.
0 .
set on Whe n
max i mum amount
the max imum t i me sett i ng.
The pr i mary adjustme nt for th e t i me o f
made by means
obta i n ed by mov i ng the
GEK-34054
by the
( i .e. , its fre edom f rom harmo n i cs)
number for a ny part i cu l ar relay;
c i rcu i ts, RL
contacts just
wh ich the contacts just
contact
This screw shoul d be held securely i n i ts support.
just clos i ng
current at wh i ch
the tap screw
plug,
Next, screw the tap screws
a screw dr i v er
w i th the tap sett i ng
intermed i ate between the
position at
The unit resets
of the t i me d i al
close its contacts
The contacts
the d i al i s set
to close the contacts;
o f the time d i al.
perma nent magnet along its supporti ng shel f ;
applica t i o n
or RC n e tworks,
by means of a
close at the
close
brush i n or out
at No. 0
the contact
i n the tap block a t the
to short t h e
( Se e F i gure 2}.
in the notches
employed,
This adjustment also permits a ny
v ar i ous
a m i n i mum current
at 90% of
determines the
whe n the
are just closed when the
on 10, the disk
there f ore
operat i on o f
Howev er, f urther
12
o f n o n -s i nuso i d a l
is s i nuso i dal.
ca n not be
however,
or saturating
woul d be espec i a lly
l amp i n the
z ero (0) t ime-d i al
can be adjusted
by mea ns o f
t ime sett i ng, there
w il l just c l os e
curre n t tra n s f ormer
i nto the tap mark e d
The r i ng may
around the e dge.
i f f or some reason,
tap setti ngs to be
i ts contacts
with i n 5% of
the min i mum clos i ng
l ength of t i m e
curre nt reaches
d i a l
must trav el
th is sett i ng g i ves
the u n i t
ad justme nt
The
a ny
by
its
i s
be
the
the
a
is
the
i s
is