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7.
Place
the
NPN
-PNP switch
to
the
PNP (in) position.
8.
Press
the
Iceo switch.
9. Press
the
lA
switch.
10. Press the ON-OFF switch
to
the
ON
(in) position.
11. Press
the
Ices switch;
then
press
the
Iceo switch.
The
SCR should now be
turned
on
.
The
meter
should
ind icate
50
or
greater on
the
leakage scale.
112. Momentarily disconnect and
then
reconnect
the
cathode
(c) lead.
The
SCR should now be
turned
off.
The
meter
should indicate less than 5
on
the
leakage
scale.
13. Release
the
ON·OFF
switch
to
the
OFF
(out)
position.
14. Disconnect
the
SCR
from
the
Tester.
TRIAC
TESTING
NOTE:
Some
high voltage triacs, those
that
have
more
than
a 1.5
volt
drop
across
the
gate
junction
when
the
triac
is
conducting,
cannot
be
adequately
tested.
Drawing M Figure 3 shows
the
schematic symbol for a Triac
(triode AC switch).
The following tests will check
the
triac
to
determine
if
it can
be properly
turned
on
and
turned
off.
The following procedure pertains
to
both
in-circuit
and
out-of
-
circuit
testing.
If
you
do
not
obtain
the
proper
results
when a triac
is
tested in-circuit, remove it from
the
circuit
and
repeat
the
tests.
1.
Be
sure
the
ON-OFF switch IS
in
the
OFF
(out)
position.
2. Identify
the
leads
of
the
triac.
3.
Connect
the
gate
(g)
lead
of
the
triac
to
the
B
connector
(white)
on
the
Tester.
4.
Connect
the
hot
lead
of
the
triac
to
the
E
connector
(red)
on
the
Tester.
5.
Connect
the
common
lead
of
the
triac
to
the
C
connector
(black)
on
the
Tester.
6. Press
the
TRANS
switch.
7. Place
the
NPN-PNP switch
in
the
NPN (out)
position.
8. Press
the
Iceo switch.
9. Press
the
1 A switch .
10
. Press
the
ON-OFF switch
to
the
ON (in) position.
11. Press
the
Ices switch;
then
press
the
Iceo switch . The
triac should now be
turned
on
. The
meter
should
indicate greater
than
50
on
the
leakage scale.
12. Momentarily
disconnect
and
then
reconnect
the
cathode
(c)
lead.
The
triac
should
now be
turned
off
.
The
meter
should indicate less
than
5 on
the
leakage
scale.
13. Press
the
NPN-PNP switch
to
the
PNP (in)
position
.
The
triac
should
remain
turned
off
. Now,
repeat
steps
11
and
12.
14. Release
the
ON-OFF switch
to
the
OFF
(out)
position.
15. Disconnect
the
triac from
the
Tester.
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