Emergency Restart Terminals; External Reset Terminals; Analog Output Terminals - GE 169 Instruction Manual

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GE Power Management
2 INSTALLATION
RTD2, and RTD3 (terminals #1-12). Other RTDs should be connected to the terminals for RTD7-RTD10 (terminals
#13-28) as shown in Figure 2-4.
The connections are made via terminal blocks which can accommodate up to #12 AWG multi-strand wire.
Note: Shielded, three wire cable must be used in industrial environments to prevent noise pickup. Wherever
possible, the RTD leads should be kept close to grounded metal casings and avoid areas of high
electromagnetic or radio frequency fields. RTD leads should not run adjacent to, or in the same conduit as
high current carrying wires. It is recommended to use a three wire shielded cable of #18 AWG copper
conductors. The shield connection of the RTD should not be grounded at the sensor end as there is an
internal ground on the 169. This arrangement prevents noise pickup that would otherwise occur from
circulating currents due to differences in ground potentials on a doubly grounded shield.

2.12 Emergency Restart Terminals

If it is desired to occasionally override relay trips or lock-outs and restart the motor, a normally open keyswitch
should be installed between terminals 54 and 55. Momentarily shorting these terminals together will cause the
thermal memory of the 169 to discharge to 0% (if RTD input to thermal memory is enabled, thermal memory can be
reduced to 0% by keeping terminals 54 and 55 shorted together for more than 11 seconds; see section 3.20). The
Emergency Restart terminals can thus be used to override an OVERLOAD TRIP. Shorting the Emergency Restart
terminals together will also decrement the relay's internal starts/hour counter by 1 and therefore allow the operator to
override a STARTS/HOUR TRIP.
Note: This option should be used only when an immediate restart after a lock-out trip is required for process
integrity or personnel safety. Discharging the thermal memory of the 169 gives the relay an unrealistic value
for the thermal capacity remaining in the motor and it is possible to thermally damage the motor by
restarting it. Thus, complete protection may be compromised in order to restart the motor using this feature.
A twisted pair of wires should be used. Connection to the 169 is made via a terminal block which can accommodate
up to #12 AWG multi-strand wire.

2.13 External Reset Terminals

An external reset switch, which operates similarly to the keypad RESET key (see section 3.1), can be connected to
terminals 56 and 57 for remote reset operation. The switch should have normally open contacts. Upon closure of
these contacts the relay will be reset. This external reset is normally equivalent to pressing the keypad RESET key
but a special reset feature can be selected on page 5 of setpoints mode, so that the keypad RESET key will not
cause Auxiliary relay #1 to be reset (see section 3.22). Keeping the External Reset terminals shorted together will
cause the 169 to be reset whenever motor conditions allow.
A twisted pair of wires should be used. Connection to the 169 is made via a terminal block which can accommodate
up to #12 AWG multi-strand wire.
2.14 Analog Output Terminals (Non-Isolated)
Terminals 58 and 59 of the 169 are available for an analog current output representing one of percentage of motor
thermal capacity used, motor current as a percentage of full load (i.e. 0-1 XFLC), hottest stator RTD temperature as
a percentage of 200 C or CT secondary current as a percentage of CT secondary amps rating. The choice of output
is selected in page 5 of SETPOINTS mode. This selection can be made or changed at any time without affecting the
protective features of the relay.
The output current range is standard at 4-20 mA. Contact Multilin if a different current range is required. 4 mA
output corresponds to a low scale reading (i.e. 0% thermal capacity used, 0 XFLC phase current, 0 C hottest stator
RTD temperature, or 0 A phase CT secondary current). 20 mA output current corresponds to a high scale reading
(i.e. 100% thermal capacity used, 1 XFLC or greater phase current, 200 C or greater hottest stator RTD temperature,
or either 1 A (or greater) or 5 A (or greater) phase CT secondary depending on the CT used).
This output is a current source suitable for connection to a remote meter, chart recorder, programmable controller, or
computer load. Current levels are not affected by the total lead and load resistance as long as it does not exceed
300 for the 4-20 mA range. For readings greater than 100% of full scale the output will saturate at 20.2 mA.
This analog output is not isolated. Terminal 58 is internally connected to system ground. Consequently the negative
terminal of the connected load device must be at ground potential.
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