As a part of Thermography Study for electrical panels, I had visited a site with my colleague. The electrician assigned to support us for the study guided us to the main distribution panel room. When the electrician opened the electrical panels one after the other, the main distribution panel, APFC panel and a few others had Polycarbonate protection cover. Polycarbonate sheets are given to protect personnel against accidental contact with the energized conductors/terminals. But eventually, they had to be removed for us to carry out thermography, though they appeared transparent. Due to the reflective surface of the Polycarbonate sheet, thermal imaging of the panel was not possible. Below is a thermal image of a panel fixed with transparent Polycarbonate sheet.
Real and Thermal image of Electrical Panel
Here are few details regarding “the installation of protection Polycarbonate sheet in the electrical panel”.
Background on the material:
- Optical clarity.
- Low conductivity.
- Very good strength and stiffness – it can be drilled without damaging the sheet material.
Advantages of having them installed:
- See-through inspection carried out, for its great optical clarity.
- Protection from dust, moisture and debris.
- Protection against electrical shock accidents for personnel.
- Availability of custom sizes.
Limitations
- The additional cost over the panel boxes.
- Must be removed if there is any maintenance or repair or any other activities.
A few scenarios would attract installation of Polycarbonate sheets; like an electrical panel which must be kept open for inspection, the purpose may be risky. Installing a transparent Polycarbonate sheet can be an advantage since safety is not compromised and inspection can be easily completed. Other than polycarbonate sheets, FRP and Hylam sheets are also used to reduce the electrical safety risk. Polycarbonate sheets are costly compared to other materials used for covering panels.
However, a facility having proper electrical connections, regular & good maintenance and highly-skilled electrician personnel with right PPE considerations as per NFPA 70E (Standard for Electrical Safety in the Workplace) can avoid installation of Polycarbonate sheet for the panels.
The thermography at the site slightly prolonged since extra time is required to remove all polycarbonate sheets from the panels. Hope, you would make a proper choice when it comes to your facility.