How to Maintain Mechanical Interlocking Systems
Functions
A source changeover system, either manual or automatic (ATS), enhances the continuity of service of an electrical distribution system.
Mechanical interlocking between the devices in the source changeover system prevents the closing of two devices simultaneously.
The use of mechanical interlocking for source-changeover systems using cables or connecting rods is compulsory for Automatic Transfer Switch (ATS) applications.
A mechanical interlocking system is made of the following parts depending on the type of MasterPact NT/NW devices:
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An interlocking plate on the side of each MasterPact NT/NW device.
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A set of cables or connecting rods linking the MasterPact NT/NW devices.
Degradation Factors
The factors which can cause degradation of the mechanical interlocking system are the following:
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Dusty or dirty environment
-
Vibration
Potential Hazards
Performing regular maintenance on the mechanical interlocking system can help to avoid the potential hazards and consequences listed in the following table.
|
Hazard |
Consequence |
|
|---|---|---|
|
Personal injury |
Equipment damage |
|
|
Inappropriate or no operation of the source changeover system |
Death or serious injury |
– |
Preventive Action
The following table lists the preventive maintenance procedures to be performed to maintain the mechanical interlocking system.
|
Maintenance program |
Preventive action |
Procedure |
|---|---|---|
|
Basic end-user preventive maintenance |
Operate interlocking systems |
Mechanical Interlocking NII_1_1 |
|
Manufacturer preventive maintenance |
Operate mechanical interlocking by cable. |
Contact your Schneider Electric field service representative. |
|
Operate mechanical interlocking by rod. |
For more information, refer to Preventive Maintenance Programs.