We have 2 sets of 3-500kcmil cables, about 250 ft long, feeding a structure. They've been sitting in an underground duct bank feeding a very small lighting load for about 15 years. They will be put back into service feeding a 600A, 120/240V, 1ph load and I thought an insulation test and a load test would be appropriate. These test would have to be performed well before the project gets underway so the right course of action can be followed if there is a failure. Is a load test a good idea? If so, I would imagine stepping the load up to full load and recording the voltage along the way would be suitable, but I'm hoping someone could direct me toward a standard that maybe would outline the duration of such a test. Thanks in advance for any information on this.
Load Testing Old Cables
- Thread starter Pdan
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What would a “load test” tell you?
Insulation test sure. That detects insulation problems. What does a load test indicate and how would you do it? Visual inspection and ohm readings (milliohm meter) is what we would use. Just short one end together and compare phases. Given that you’ve had some load for years moisture won’t be a factor.
Insulation test sure. That detects insulation problems. What does a load test indicate and how would you do it? Visual inspection and ohm readings (milliohm meter) is what we would use. Just short one end together and compare phases. Given that you’ve had some load for years moisture won’t be a factor.
ron
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Load testing is typically for termination or transformer / winding integrity. Apply an artificial load bank and check terminations with an IR camera.
zbang
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- Roughly 5346 miles from Earls Court
Since it's been energized, presumably all conductors, then I'd just go with the megger test. However.... how old are these cables and what's the insulation type? It may be prudent to replace them now anyway, and possibly the terminations at each end.
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