Resetting The 269 Relay; Relay Self-Test - GE MULTILIN 269 MOTOR MANAGEMENT RELAY Series Instruction Manual

this way the lock-out is avoided. The Emergency Re-
start feature will also reduce the relay's starts/hour
counter by one each time the terminals are shorted
together, so that a STARTS/HOUR INHIBIT can be
defeated.
When RTD input to thermal memory (SETPOINTS,
page 5) is enabled and the Emergency Restart feature
is used, thermal capacity will be reduced to 0% only for
as long as the Emergency Restart terminals are held
shorted (note: it may take up to 11 seconds for the
"Thermal Capacity Used" display to change to 0%).
When the Emergency Restart terminals are opened
again, the thermal capacity will change to what is used
according to the maximum stator RTD temperature and
Figure 3.7. Thus, momentarily shorting the Emergency
Restart terminals with RTD input to thermal memory
enabled may not reduce the thermal capacity used to
0% when the motor is hot.
Shorting the Emergency Restart terminals together will
have no effect unless the motor is stopped. Thus hav-
ing these terminals permanently shorted together will
cause the memory to be cleared when the motor stops.
This will allow for an immediate restart after an
OVERLOAD TRIP.
Caution is recommended in the use of this feature
since the 269 relay's thermal protective functions
will be overridden and it is possible to damage the
motor if Emergency Restart is used.
All of the inhibits will be cleared if the Emergency Re-
start terminals are shorted with the exception of the
backspin timer (section 3.9). Due to the poten-
tially dangerous conditions of a rotor spinning back-
wards, the only way to defeat the backspin timer is to
turn the setpoint "OFF".

3.22 Resetting The 269 Relay

Resetting the 269 relay after a trip must be done
manually by pressing the RESET key, or by shorting
together the External Reset terminals. Alarm functions
can cause latched (manual reset) or unlatched (auto-
matic reset) output relay operation depending on the
RELAY ALARM LATCHCODE (SETPOINTS mode,
page 5). A latched relay will stay activated until the
RESET key is pressed or the External Reset feature is
used. Remote reset via communications is also possi-
ble. See Chapter 4.
If a trip/alarm condition persists (eg. a high RTD tem-
perature), or if the relay has locked out the motor,
pressing the RESET key will cause the flash message,
RESET NOT POSSIBLE - RESET NOT POSSIBLE -
Condition still present. Condition still present.
to be displayed. However, shorting the Emergency
Restart terminals together will reduce the lock-out time,
allowing the relay to be reset immediately.
Note: If RTD input to thermal memory is enabled
(SETPOINTS, page 5) the lock-out time may not be
reduced to 0 minutes since the thermal capacity
available is dependent on the RTD bias curve and
the maximum stator RTD temperature (see section
3.21).
If the External Reset terminals are permanently shorted
together the relay will be reset immediately when motor
conditions allow (eg. when the lock-out time runs out).
If the 269 relay trips and then loses control power, the
trip function will become active again once control
power is re-applied. For example, if a GROUND
FAULT TRIP occurs and then control power for the re-
lay is removed and later returned, the message
"GROUND FAULT TRIP" will appear on the display and
the output relay assigned to the Ground Fault Trip
function will become active.
Note: If control power is removed for more than
one hour after a trip, the 269 relay may be reset
when power is re-applied (for O/L trips).

3.23 269 Relay Self-Test

The 269 relay's internal circuitry self-test consists of
three separate tests. A/D, RTD, and memory circuitry
tests are continually performed. The A/D test involves
sending a known, precise voltage level through the A/D
circuitry and seeing if it is converted correctly.
RTD test involves reading a known, internal resistance
and checking to see if the correct temperature is de-
termined. To test the memory circuitry, test data is
stored in the 269 relay's non-volatile RAM and is then
read and compared with the original data.
Should any of these tests indicate an internal circuitry
failure, the "SERVICE" LED will start to flash and the
output relay programmed for the self-test feature will
activate.
Note: When a relay A/D or memory self-test failure
occurs, all metering and protective functions will
be suspended. The ACTUAL VALUES display for all
parameters will be zero in order to avoid nuisance
tripping. When in this state, the relay will not pro-
vide motor protection. If a memory failure occurs,
the factory setpoints will be reloaded into the 269.
If an RTD hardware failure occurs the "# OF
STATOR RTDS USED" setpoint will be automatically
set to 0 and the RTD ALARM and TRIP levels will be
automatically set to OFF; however all current-
related functions will continue to operate normally.
3 SETUP AND USE
The
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