GE Industrial Solutions ASTAT-XT RVSS PANEL - Manual (Page 19)

DEH40622 - Page 11 AN BL-0350, Rev.01, 08/20/2010
ASTAT-XT RVSS PANEL
1. Make sure there is not an unintended additional loading on the motor
resulting in the excessive current.
2. Try another OL relay. Perhaps the tolerances on the one included
with your panel are unfavorable.
If the overload relay dial is set correctly but tripping occurs on
across-the-line starts this is probably due to a large load inertia which
results in high starting current being applied for a longer time to
accelerate the motor from a stopped to full speed condition. Traditionally
the problem of starting motors with high inertia loads across the line has
been solved by a number of methods falling into the category of soft-
starters. The ASTAT-XT Soft Starter is, by its very nature, a “soft-starter”
since it applies a very low voltage to the motor when it is stopped and
gradually increases to full voltage at full speed. Recognizing that this
problem can only occur during full voltage across-the-line starts (in other
words, starting in BYPASS mode), Refer to section 6 of this document on
trouble shooting assistance
WARNING: The overload relay should not be turned to a higher
setting than allowed by the rules above to allow starting the motor
across the line without tripping. Doing so will compromise the overload
protection which could lead to component damage or fire which could
threaten personnel safety. Refer to NEC for further information.
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