Allen-Bradley 825-P, User Manual

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80 Rockwell Automation Publication 825-UM004D-EN-P - November 2012
Chapter 6 Configuring Protection & Logic Functions
Figure 30 - Monitoring Starting Time
Star-Delta (Wye-Delta)
Starting
The 825-P issues the command to switch from Star to Delta (Wye to Delta) as
soon as the starting current has dropped to the rated value and the motor has
reached its normal speed in Star (Wye). If starting has not been completed within
the normal time for this application (Max Star Time setting, if used), the relay
makes the change to delta, regardless of the speed attained.
You can switch the maximum permissible time for star (wye) operation on or off.
If it is off, the change to delta is made solely based on the motor current. If the
motor has to be switched off when the total start time (Star and Delta) exceeds a
set time, the Start Monitoring must also be used.
1 =
2 =
Motor Starting Current
Rated Conditions
Start Motor Time
Tripping (if starting lasts too long)
tv =
3 =
≤ 1.1 Ie
1
2
3
t
tv
≥ 1.2 Ie
I
Table 22 - Star-Delta Settings
Setting Prompt Setting Range Factory Default
STAR-DELTA ENABL Y, N N
MAX STAR TIME Off, 1…600 s Off
NOTE: In addition to enabling the Star-Delta, you must assign Star and Delta to Auxiliary output
relays (one each).