joebell

I got a call to check some 24 Volt lighting that the construction side of my company installed. There was a 30' section of soffit lighting that was out. I found a burnt wire coming off the secondary side of the transformer. This transformr is rated for 1000 watts but has 2 -500 watt circuits that can be fed from it. I then counted 100 -5 watt lamps on this section of lighting.This lighting is on more than 3 hours so the load should be consdiered continuos ,but a couple of the guys I spoke with in the company think that this installation should be fine and that it must be a bad transformer. I feel the circuit is over loaded with the 500 watt lamp load not to mention the voltage drop ( Approx. 60' from trans to last lamp ). Thoughts?
Joe

frank

A 1kva transformer unless specifically stated is not continuously rated. Certainly in the first instance you need to uprate the transformer. But I think your fault may be simply due to over current demand made upon the cable supplying the lighting. Each leg needs to be capable of carrying 21 amps. So you need to be sure that your circuits are capable of that and also take into account continuous running and volt drop etc.So make your cable at least 25% larger.

Frank