Customer Question

A customer inquired whether a 15kV Load Interrupter Switch (LIS) can be used in a 5kV-rated switchgear.

Although the catalog suggests no electrical compatibility issues, we requested internal confirmation regarding mechanical installation compatibility and other relevant design considerations.

Engineering Response

• The 5kV and 15kV Load Interrupter Switches are the same product.

• Both share the same mechanical design, dimensions, and installation criteria.

• The only aspect to confirm is the operation handle configuration (Left Operation vs. Right Operation).

• As per the customer’s reference email, the only difference appears to be the voltage rating, which does not affect mechanical compatibility.

Key Design Considerations

When applying a 15kV LIS to a 5kV SWGR, the following should be reviewed:

1. Operation Handle Configuration

   • Must match the existing switchgear layout (Left or Right operation).

2. Mechanical Interference

   • Ensure there are no obstructions or design mismatches during installation.

3. Overrating Impact

   • Using a higher-rated device (15kV) in a lower-rated system (5kV) is generally acceptable, but confirm no adverse effects on protection coordination or space requirements.

✅ Conclusion

It is technically acceptable to apply a 15kV LIS to a 5kV Switchgear, given that the operation handle configuration is the same. The product itself is identical, and installation conditions remain unchanged.

If any field application examples or case studies are available, please share them for future reference.