With a combination of the der JBL TempSet Unit L-U-W with metal halide lamps (e.g. JBL ReptilDesert L-U-W Light or JBL ReptilJungle L-U-W Light) the lighting unit suddenly switches itself off.
When the lamp suddenly switches itself off after some time of operation this is usually a sign that the electronic ballast of the lighting unit has overheated. For security reasons the ballast is equipped with an integrated overheating protection. If the ballast is not sufficiently aerated, for example when installed in the gap between terrarium back and living room wall, it comes to an automatic switch off to shelter the unit against overheating damage. In such a case please move the ballast unit to a place with sufficient aeration.