ABB KD-10 Instruction Leaflet page 29

Type KD-10 and KD-11 Compensator Distance Relay
THE KD COMPENSATOR DISTANCE RELAYS CALIBRATION
A calibration and maintenance program should in-
volve two steps: 1) a receiving acceptance check
and 2) a routine (periodic) maintenance program.
These two steps are outlined below.
1.0 RECEIVING ACCEPTANCE
Received relays should be subjected to the checks
outline in the applicable I.L. These checks will insure
that there is no shipping damage and the relay has
been received in the same calibrated condition as it
left the factory. They will insure that set-up proce-
dures such as removing contact blocking has been
accomplished. A receiving acceptance check should
include the following steps:
a. Perform all of the mechanical and electrical tests
listed in the receiving acceptance section of the
applicable I.L., include the maximum torque an-
gle test, even if it is not called for in some I.L.'s.
b. Follow the appropriate test procedures outlined in
Instruction Leaflets covering the KDAR Field Test
Unit. It is suggested that all dial test readings in
each test be recorded for future reference. This
information will be very helpful in recognizing
possible drift or electrical characteristics.
c. If the settings to be applied to the relay when it is
installed are known, the relay should be set to
these settings and checked with the field units
as noted in step 2 above. A record for future ref-
erence should be taken. The relay test values
using the KDAR test unit should check to be
within ± 7 percent of the relay settings.
2.0 ROUTINE MAINTENANCE
The relay should be checked periodically at time in-
tervals dictated by pervious experience and practic-
es. ABB recommends the time interval between
checks be a maximum of two years. Routine mainte-
nance should include at least the following steps.
a. Repeat step 2 and 3 under RECEIVING ACCEP-
TANCE and record test results.
b. Compare test results with pervious results. If any
test values deviate from previous checks by
APPENDIX B
AND MAINTENANCE PROCEDURES
more than 5 percent, recheck relay performance
in line with the receiving acceptance checks out-
lined above step 1.
c. Retain records of test results on each particular
relay. During each routine maintenance, the
records should be analyzed to determine if there
is any evidence of drift; i.e., continued change in
characteristic in the same direction. Evidence of
drift should be traced to the particular element
involved, usually a capacitor or resistor and this
element replaced.
d. Some of the more common component prob-
lems may be detected as follows:
With the relay mounted on a panel and ener-
gized by station C, T's & P. T's open all trip cir-
cuits and all current switch positions 12, 13, 14,
15, 16, 17, 18, 19, and phase C voltage switches
(terminal 9), and if applicable, an additional
switch position on the separately energized 3φ
unit. Check the internal schematic for your par-
ticular relay. Jumper terminal 7 to terminal 9 and
to any other applicable switch normally connect-
ed to phase C, on the relay side (upper half of
the switch). The contacts of both operating units
should stay open. If the 3-phase unit contact
closes, it indicates misadjustment of resistor,
R , or potentiometer, P
3A
cause), or defective capacitor, C
instructions for trouble shooting in Section 3.3.
"SUGGESTED PROCEDURE FOR DETECTING
AND REPLACING DEFECTIVE C
TOR FOR KD-4, KD-5 AND KD-10 RELAYS"
(page 31), and the proper instruction leaflet for
KD/KD-1, and KD-10/KD-11 relays.
If phase-to-phase unit closes, recheck for:
• KD/KD-1 relays
• KD-4/KD-41 & KD-5
• KD-10/KD-11
41-490J
(most common
3A
. Follow the
3C
CAPACI-
3C
R & R -Calibration
MA MC
R -Calibration
AC
X -Adjustment
LAC
29