Volt drop calculation

[pcasey]

So to re-cap…it’s impossible for the volt dropto cause the fuse to burn out as higher resistance or lower voltage at the loadleads to lower current passing through the circuit. Therefore it must be that aloose connection on the fuse terminal that caused the problem, which makessense as 50A left running all night would not do it any good. I might suggest alarger transformer with a thermal cut out and a timer on the primary that cutsout after 5 hours although 5OA left on for 5 hrs is not great either but a600VA transformer should handle it? I could always fit LED lamps but I’m notsure whether they need a specific type of transformer which will be a costly solution….any ideas? Cheers, Phil.

 

[DPG]

LED lamps would save them a few quid on their leccy bill - that's a fair amount of consumption if they're left on an hour or two at a time. Daz

 

[Richard Burns]

So to re-cap…it’s impossible for the volt dropto cause the fuse to burn out as higher resistance or lower voltage at the loadleads to lower current passing through the circuit. Therefore it must be that aloose connection on the fuse terminal that caused the problem, which makessense as 50A left running all night would not do it any good. I might suggest alarger transformer with a thermal cut out and a timer on the primary that cutsout after 5 hours although 5OA left on for 5 hrs is not great either but a600VA transformer should handle it? I could always fit LED lamps but I’m notsure whether they need a specific type of transformer which will be a costly solution….any ideas? Cheers, Phil.

The fuse burn out would have likely been due to a slightly loose connection that will slowly get hotter and hotter as it gets worse, the running overnight may well have completed the task.
The volt drop will not cause the lights to stop functioning, if they are incandescent they will just be a bit dimmer then intended.
It would be better to have the transformer as close as possible to the lights (within regulation constraints) but a bigger transformer will not make a lot of difference if the original was rated for the load, it may run a bit cooler but that does not seem to have been the problem.
From what you say replacing the fuse and any damaged cables would solve the problem and if the terminations are done securely then there should not be a problem.
A cut out timer would probably be good from an energy saving point of view but it would need to be adjustable so that if they intend them to be on for eight hours they can do so.