TRT Maintenance Guide (non-CLO)
Maintenance Factors for TRT Luminaires
When designing a road lighting scheme with TRT lanterns, the maintenance factors to be used for CLO and non-CLO designs are different. The maintenance factor design guides (Maintenance Factors for non-CLO Luminaires and Maintenance Factors for CLO Luminaires) provide an in-depth explanation of how to calculate maintenance factors for TRT luminaires and are aligned with BS5489-1:2020 Annex C.
Following 10 years of testing and monitoring of non-CLO TRT lanterns in use, the evidence gathered supports moving to depreciation over 100,000 hrs being extrapolated to being no more than 5%. TRT’s approach to recommended maintenance factors remains cautionary and this change from the previous allowance for 10% depreciation to 5% has only been made following the gathering of appropriate and robust test results over 10 years.
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