Setting the Neutral Protection
Selecting the Type of Neutral Protection Using the Dial
On four-pole circuit breakers, it is possible to select the type of neutral protection for the fourth pole using the three-position dial on the ComPacT NS circuit breaker:
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Neutral unprotected (4P 3D)
NOTE: With the 4P 3D setting, the current in the neutral must not exceed the rated current of the circuit breaker. -
Neutral protection at 0.5 In (3D + N/2, factory setting)
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Neutral protection at In (4P 4D)
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Cover for neutral protection three-position dial.
Follow these steps to set the type of neutral protection.
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Remove the cover of the switch.
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Select the protection type.
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Put the cover back in place.
Setting the Neutral Protection Using the Keypad
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Select
> .
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Use the buttons below the display screen to select the neutral CT used by the neutral protection:
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None disables the neutral protection.
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Internal for four-pole circuit breakers with internal neutral CT.
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External for three-pole circuit breakers connected to an external neutral CT.
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Use the buttons below the display screen to set the neutral protection type.
|
Circuit breaker type |
Neutral protection type |
|---|---|
|
Four-pole |
OFF: no neutral protection N/2: half neutral protection N: full neutral protection |
|
Three-pole |
OFF: no neutral protection N/2: half neutral protection N: full neutral protection 1.6 x N: oversized neutral protection |