GEK-86038
Check that the a u xili a ry circuits function as designed and that the reset;
�echanisms function pro perly.
CALIBRATION PROCEDURE
The IRT relays have been calibrated at the facto ry and the c alibration settings
should not require any a dditional adjustment.
Recalibration should be considered
only after all of the checks , tests and servicing notes , includin g cleaning the
temperature selection dial rheostat , have been accomplished.
If the relay still
shows that it is out of calibration after the tests , checks and service listed in
the
INSPECTION, ACCEPTANCE TESTS, PERIODIC CHECKS AND ROUTINE MAINTENANCE
section of
this instruction book have been completed , proceed as follows:
1.
Remove all windu p f rom the induction disk spring so that the moving contact in
the rela xed position just makes contact with the left stationa ry contact.
2 .
Wind the spring counterclockwise goo.
The ring may be turned by inserting a
screwdriver in the notches a ro und the ed ge.
The notches a re s paced at abo ut
30° increments.
This windu p wi
11
ca use the moving contact to touch the right
stationa ry contact o r the moving contact sto p.
3 .
Set the adjustable ta p ( slide band ) on R2 to a position at the center of the
a djustable range of the resisto r.
4 .
Using AWG No. 12 o r
1
a r ge r .. diameter wire , with a ma ximum wire
1
ength of 12
inches , connect resisto r A from Table
g
across terminals 4 and 5 .
Sho rt
terminals 5 and 6 to gether.
5 .
Turn the temperature selection dial to the 16QOC setting.
6.
Apply rated voltage and f requency to the o perating circuit.
7.
Adjust R1 until the moving contact just makes the left IRT stationa ry contact
(IRTL ). Tighten the slide band in this position. If the Rl slidin g tap does
not permit this setting p recisely , a djust the s pring windu p until this setting
is achieved. It is impo rtant that the windu p a djustment not exceed �300 from
the previously set goo windu p position.
No fu rther a djustment to the wind u p
s prin g is pe rmitted after this adjustment is made.
8.
Disconnect power f rom the o perating ci rcuit.
Remove resisto r "A" and replace
it with resisto r
"
B
."
Terminals 5 and 6 sho uld remain shorted to gether.
Set
the temperature selection dial to 8QOC .
Rea pply power to the o pe rating
circuit .
g.
Adjust the slide band on resisto r R2 until the IRT l eft stationa ry contact
( IRTL ) and the moving contacts just make.
Ti ghten the slide band in this
position .
10. Disconnect power from the o perating ci rcuit.
Remove resisto r
"B"
and replace
it with resisto r "C ," o r with a resistor having a resistance that co rresponds
·"\
)
\
.)
to the resistance of an RTD at some selected tem peratu re .
See Selection of
Simulated RTD Load fo r resisto r value selection method .
Terminals 5 and 6
sho uld remain sho rted to gether.
Rea pply power to the relay.
Set the
18
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