How to Maintain the Arc Chutes
Functions
The arc chutes of the device:
-
Are mounted on each arc chamber of the breaking unit
-
Are composed of splitters and filters
The splitters of the arc chutes limit the stress exerted on the installation by:
-
Helping to extinguish the arc
-
Absorbing the arc energy under normal electrical operations and electric faults
The filters of the arc chutes filter the pressured gas expelled out of the arc chamber and cool it to a temperature at which it is no longer ionized and is therefore non-conductive.
Degradation Factors
The factors which can cause degradation of the arc chutes are the following:
-
Frequent switching operations at rated current
-
Stresses due to high short-circuit currents
Potential Hazards
Performing regular maintenance on the arc chutes can help to avoid the potential hazards and consequences listed in the following table.
|
Hazard |
Consequence |
|
|---|---|---|
|
Personal injury |
Equipment damage |
|
|
Arc flash |
Death or serious injury |
– |
|
Insulation resistance of the case too low and impulse voltage |
Electric shock |
– |
|
High short-circuit current |
– |
Degradation of the breaking unit |
Preventive Action
The following table lists the preventive maintenance procedures to be performed to maintain the arc chutes of the device.
|
Maintenance program |
Preventive action |
Procedure |
|---|---|---|
|
Intermediate end-user preventive maintenance |
Check the condition of the breaking unit. |
Breaking Unit NIII_Z_1 Breaking Unit NIII_2_1 Breaking Unit NIII_ZA_1 |
|
Check mounting of arc chutes and filter cleanliness. |
Breaking Unit NIII_Z_2 Breaking Unit NIII_2_2 Breaking Unit NIII_ZA_2 |
For more information, refer to Preventive Maintenance Programs.