ABB REL 551 2.3 Series - Page 130

124
Two step time delayed phase overcurrent
protection (TOC2)
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Prepare the terminal for test as outlined in section “Preparing for test” in this chapter.
Ensure that the maximum continuos current of a terminal does not exceed four times its
rated value, if the measurement od the operating characteristics runs under constant
voltage conditions.
To verify the settings the following fault type should be tested:
• One for a phase-to-earth fault
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The operate time shall be tLow+operate time of the low set stage.
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If I>Low is set higher than I>Inv, check that there is no trip signal
TOC2-TRLS when the current is less than I>Low.