Thermographic Surveying (Thermal Imaging)
A useful addition to a preventative maintenance program. ETS can carry out a thermographic scan of all areas likely to be running too hot or too cold (in the case of failed refrigeration insulation for example). Any areas of the site that register as potential too hot or too cold (be that electrical or mechanical) will be captured as thermal images and photographic images and will be included in the report.
It must however be understood that thermal imaging is not a substitute for Periodic Inspection and Testing. It can however provide a useful interim back up in a maintenance program between formal inspection and testing and can complement the overall system information available to the duty holder.
It can also be very beneficial in situations where access may be restricted or shutdowns to fully test are not possible. Some of our competitors claim thermal imaging to be the be all and end all, but it is not a substitute and it should never be relied upon as the sole means of fault identification in the preventative maintenance program of an electrical systems.
What Thermal Imaging can identify
High resistance connections
Over loaded cables
Over loaded fuses or breakers
Imminent motor or conveyor bearing failure
Motor windings over heating
Overheating in distribution equipment
Phase load imbalance
Hot spots in high level lighting (easily scanned from the floor)
Heat build-up in overcrowded trunking
Thermal insulation breakdown (hot or cold)
What Thermal Imaging cannot identify
Over rated fusing
Under rated cables (unless they are over loaded at time of survey)
Physically damaged equipment, possibly exposing live parts
Lack of earth continuity
Undersized earth conductors
Prospective fault currents too high
Prospective fault currents too low
Poor insulation resistance
Broken ring mains
Lack of RCD protection
Protective device cascading of discrimination failures
And many more...
Thermal imaging can be carried out on a site-wide basis fairly quickly and cost effectively and is largely unintrusive. However, panels and cabinets will need to be opened in order to scan the components within, this may require a shutdown of the panel to achieve. The thermal imager needs to physically see any hot item to detect it, it cannot see through solid barriers such as doors or cabinets.