Why Vermin Proofing of HT & LT Panels are must and must be periodically checked

Hello Friends/Sir,

We love wildlife as much as the next person. But when they get into your Electrical Installation, they becomes ‘Vermin’.

Animals, mostly Reptiles & Birds can cause significant damage to your Critical & Expensive Electrical Installations, since they love to setup their houses in the Nooks and Crannies where control and protection wiring is housed. The warmth and seclusion is particularly attractive to them.

In all the plants, where we Served, Visited or Know, we have noticed that Mouse & Lizards have a special affection towards Electrical Switchgear and Instrumentation Panels.

Sharing with you all, one such Incident and Photos for what we have observed during maintenance of HT Panel of 11 kV.

As a part of service, we do complete Switchgears (HT Panel & LT Panel maintenance which includes, Relay Testing, Breaker Servicing & Testing, Control panel cleaning & Tightness, CT & PT testing) & Switchyard Servicing & Maintenance in various plants.

During maintenance of one VCB of 11 kV panel board, we found 2 Nos. of Mouse inside the Breaker as shown in Pictures. We felt sorry for the Mouse. Anyways, we are sharing here the pictures of Mouse, trapped and dead in breaker. Photos are shared so that others can also learn from the incident.

Coming back to the point, lets us think what if these 2 mouse would have travelled towards 11 kV bus? This could have leads to system breakdown worth rupees Lacs/Crores, risk of life to individuals and owing liability of this incident, last but not the least, Transfer / Suspension / Termination from the Maintenance team as a consequence. Maintenance team must be thankful that this hasn’t happened and has been rectified then.

Now, when inquired with Maintenance Engineers, they said, it was some 2.5 years back when they applied Aluminum tape and Puff seal at various holes inside the panel. We investigated & checked for the same and found that while applying aluminum tape for that panel, Individual might have forgot to clean the base where tape was applied, hence it got opened due to improper adhesive contact with panel and same has let Mice to get into the Panel easily.

Out of 50 Nos. of panels, only one panel was found so, leaving error margin of 2% and this could have caused Marginally higher loss.

Jokes apart, we advise to all the customers and their Maintenance Team either we serve or not, to check their Switchgear Panels during every annual shutdown or Complete cleaning, Servicing & Maintenance of HT Panels in every 2 years for safety and surety. Although Checking of Busbar is altogether a different issue and required heavy planning for complete black out.

Since, almost every plant goes for Relay Testing and Breaker servicing every year through 3rd party. We, System Protection, also serve in more than 250 plants for Circuit Breakers and Relays independently. Now what’s left in Panel is Control Wiring Simulation & Tightness, Cleaning of complete Panel cubical (front and rear), CT & PT testing (if Required) and for such jobs, Testing/Service Engineer will take Technicians & Helpers (Mostly non-skilled) from contractor and then will indent cleaner, brush, scrubs, Blower (If not available), Tool kits like screwdriver set, spanner set (If Not available) and then to take care and follow up for all the indents and quality of work done (that too from Non-Skilled workers).

This is how many times Maintenance suffers and leading to such incidents and consequences as a result.