Earth-Leakage Protection (ANSI 50G-TD)
Earth-leakage protection is a protection against earth fault with a very high sensitivity. It is generally used in TT or IT earthing systems but could also be used in TN earthing systems in some circumstances. Earth-leakage protection is a residual current protection based on current measured by a rectangular sensor encompassing the three phases or the three phases and neutral. MicroLogic 7.0 X earth-leakage protection including VPS module complies with IEC 60947-2 Annex B. It is a type A residual-current device (RCD).
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HAZARD OF EARTH-LEAKAGE PROTECTION LOSS |
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oDo not use MasterPact MTZ with embedded MicroLogic 7.0 X control unit without connected rectangular sensor for earth-leakage protection. oOnly ever use Schneider Electric LV833573SP or LV833574SP earth-leakage protection sensors with MasterPact MTZ with embedded MicroLogic 7.0 X control unit. |
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Failure to follow these instructions can result in death, serious injury, or equipment damage. |
Earth-leakage protection is available on:
oMicroLogic 7.0 X control units for IEC standard connected to an external rectangular sensor
o3-pole and 4-pole circuit breakers
The external rectangular sensor is required to measure the residual current.
For information about installation of the rectangular sensor, consult the instruction sheet on the Schneider Electric website: NVE35468
The VPS voltage power supply module is delivered with MicroLogic 7.0 X control units to supply power to the control unit in case of a low-level electrical fault and no load, where the power supply based on current flowing through the circuit breaker is not high enough.
The VPS is mandatory to comply with IEC 60947-2 Annex B.
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Earth-leakage protection is definite time. The earth-leakage protection threshold IΔn sets the level of earth-leakage at which the circuit breaker trips when reaching the earth-leakage protection time delay Δt. |
The earth-leakage protection settings are:
oIΔn: earth-leakage protection threshold
oΔt: earth-leakage protection time delay
They can be set as follows:
oOn the MicroLogic X display screen, at Home > Protection > I Earth Leakage
oWith EcoStruxure Power Commission software (password-protected)
oWith EcoStruxure Power Device app (password-protected)
oBy sending a setting command using the communication network (password-protected).
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Setting |
Unit |
Range |
Step |
Factory setting |
Accuracy |
|---|---|---|---|---|---|
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IΔn |
A |
0.5–30 |
0.1 |
0.5 |
Complies with IEC 60947-2 Annex B |
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Setting |
Unit |
Setting Value |
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|---|---|---|---|---|---|---|
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Δt |
s |
0.06 |
0.15 |
0.23 |
0.35 |
0.80 |
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Non-tripping time |
s |
> 0.06 |
> 0.15 |
> 0.23 |
> 0.35 |
> 0.80 |
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Maximum breaking time |
s |
< 0.14 |
< 0.23 |
< 0.35 |
< 0.80 |
< 1.00 |
Test the operation of earth-leakage protection as follows:
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Step |
Action |
|---|---|
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1 |
Check that the circuit breaker is closed and the control unit is supplied with power (ready LED is flashing). |
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2 |
Use a thin screwdriver to briefly push in (< 1 s) the test button (T) on the front face of the MicroLogic X control unit. This action is recorded as an event. |
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3 |
The circuit breaker trips. An event is generated. |
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4 |
If the circuit breaker does not trip, an event is generated. Contact your field service representative. |
The function generates the following predefined events:
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Code |
Event |
History |
Severity |
|---|---|---|---|
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0x6404 (25604) |
IΔn trip |
Trip |
High |
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0x641E (25630) |
IΔn/Ig test trip |
Trip |
High |
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0x6204 (25092) |
IΔn start |
Protection |
Low |
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0x6304 (25348) |
IΔn operate |
Protection |
Medium |
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0x142A (5162) |
IΔn/Ig test button pressed |
Diagnostic |
Low |
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0x1413 (5139) |
IΔn/Ig test - no trip |
Diagnostic |
High |
Predefined events cannot be modified by the user. For general information about events, refer to Event management.
Protection events are generated as follows:
oThe start event is generated when the protection picks up.
oThe operate event is generated when the protection time delay elapses.
oThe trip event is generated when the circuit breaker tripping voltage release (MITOP) activates.
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Code |
Event |
Recommended actions |
|---|---|---|
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0x6404 (25604) |
IΔn trip |
Reset the device or use the Power restoration assistant within the EcoStruxure Power Device app. |
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0x641E (25630) |
IΔn/Ig test trip |
Reset the device or use the Power restoration assistant within the EcoStruxure Power Device app. |
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0x1413 (5139) |
IΔn/Ig test - no trip |
Restart the test. If it fails again, replace the control unit. |
For information about resetting the circuit breaker after a trip due to an electrical fault, refer to the relevant document:
oMasterPact MTZ1 - Circuit Breakers and Switch-Disconnectors - User Guide
oMasterPact MTZ2/MTZ3 - Circuit Breakers and Switch-Disconnectors - User Guide
