How to Test the following features of EntelliPro:
- Overcurrent - Phase Unbalance Loss - Stalled Rotor - Ground Fault - Thermal Memory -
GE offers 4 current transformer types:
EntelliPro CT 8 (you apply 8A primary we get 32mA secondary)
EntelliPro CT 32 (you apply 32A primary we get 32mA secondary)
EntelliPro CT 64 (you apply 64A primary we get 32mA secondary)
EntelliPro CT 630 (you apply 630A primary we get 32mA secondary)
If lower CTs setting values are desired, multiple primary turns feed-thru can be added. Please note that 32mA secondary injection should correspond to 1 x CT value set in the WinESG parameterization screen. Refer to figure 1.
The Motor Rated Current (Ir) (percentage of CT) is the value used for overload, phase loss, stalled rotor protections.
For example if CT is set to 8Amps and FLA to 4A (FLA = ½ CT), then 1 x FLA = 16 mA (32/2) on the secondary
Figure 1.
EntelliPro CT setting
For easy set-up requiring voltage to be applied minimum number of inputs (note: voltage must be applied per Entellipro input voltage rating) we recommend the settings on figure 2.
DO41 contactor (which controls the motor) will be used to monitor the trip time.
DI98 should be active to set the operation to Local mode
DI97 can be used to turn on contactor DO41
DI96 can be used to turn off contactor DO41
Customers may have different settings to turn on the motor contactor which is acceptable.
CT Value
Motor Rated Current
Sequence of operation to measure trip time:
Turn On contactor D041 either by using WinESG control – figure 3 or by applying voltage to DI97
Apply current to phases
Trip time should be measured from the time current is applied to the time contactor D041 opens
Figure 2. Simple configuration settings. Note you must enable the functions you want to trip
Figure 3. On/OFF control using WinESG
Overload Test
Set the phase (very important). If overload testing is done by applying current to a single phase set the “phase” to 1-phase. Set the Trip class desired.
Figure 4. CT, Trip class, Phase settings
If CT is 8A (32 mA secondary) and motor full load is also 8A (32mA) it means the 1X point is 32mA.
If 2x overload trip is desired, apply 64mA to the secondary. EntelliPro will trip per the Trip class selected according to the trip curve on the manual (refer to overload curve section)
Phase Unbalance / phase loss Test
For phase unbalance test the Phase unbalance/loss delay must be set (from 1 to 15 seconds) and Phase set to 3-phase. Refer to figure 5.
We consider phase unbalance whenever the minimum of the three phase current is less than 70% of the maximum phase current. For instance you apply 32mA on phases A and B and 19 mA to phase C.
We consider phase loss whenever the minimum of the three phase current is less than 40% of the maximum phase current. For instance you apply 32mA on phases A and B and 0 mA to phase C.
Overcurrent / Stalled Motor Test
Threshold 1 (over current) sets the level of current that must be applied for overcurrent / stalled motor. Refer to figure 5. The time to trip is set on Overcurrent delay time (in seconds) as shown in figure 6.
Figure 5. Overcurrent /stalled motor current magnitude.
Figure 6 – Overcurrent / Stalled motor time delay
Operation:
Close contactor D041
Apply 5 x 32 mA on all phases and start the timer
The contactor should open in 5 seconds (per this setting).
Note: Make sure you set the overload trip class appropriately (or lower the stalled motor magnitude) so you trip on stalled motor and not a standard overload.
Ground Fault protection
Ground fault settings are shown in figure 7. In this case it is set to 0.2 x Ir and 1000msec delay
Figure 7. Ground Fault setting
The GF is a sum of all three phases.
There are important notes needed to understand the GF operation: The GF is disabled when the average of the three phases falls below 50% of motor load or exceeds 3 times the motor load.
In this case the motor load is 32 mA secondary. So if the average of the three phases falls below 16mA or is greater than 96 mA then the GF is disabled.
Apply 1x (32mA) current to phases A and B. Make sure the current on phases A and B are 180 degrees apart so the summing will be zero. Then apply GF trip current on phase C – in this case the trip magnitude is set to 0.2 (0.2 x 32 = 6.5 mA). The unit should trip in 1 second per Time delay of 1000msec.
It is always recommended that the trip current be 5% higher than nominal.
Thermal memory
Cool down factor must be set as shown on figure 8. The higher the setting the longer it takes the unit to reset and allow the motor to start after an overload trip.
Figure 8. Cool down factor / thermal memory
Under Windows > Measure you will see the screen shown in figure 9
Figure 9. Time to restart
Sequence:
Perform an overload trip
After the trip and depending on the cooling time set, the “time to re-start” on the panel shown in figure 9 will have a value. To test the thermal memory: try to restart while non-zero (you should not be able to turn on contactor D041 until the time is zero.
Thermal memory mimics the motor cooling down period.
