Mike Dolt Enterprises
Mike Dolt Enterprises
User: bowman, Location: Hawthorne, New York NEC: 2014
Asked on: Thursday, November 4, 2004 at 12:10 pm EST
Answered on: Thursday, May 9, 2024 at 12:46 pm EDT
Question: I haven't had this problem before..... the situation is a wharehouse relamp. Total amount of fixtures is approx. 166. All 400 watt mh highbays. The first phase consisted of about 50 where upon energizeing them I had about 5-6 capacitors go. Not all at the same time and since it was ab switching I didnt energize all 50 at once either. Then next day had couple more go and 3rd day the same at diferent times and some after they have been burning for a few hours(total of 12 ). fixtures are wired 480v fed from 20 amp breakers through lighting contactors. lights are dropped level height by 3/4 rigid niples cut from close to 24''....any help or advice is apreciatedalso had the lighting rep and tech support out which i was very appreciative of their help and fast response to the situation...however just wanted to throw it out and see if i can learn something..
Possible Causes
1. Overvoltage
Check the line voltage at the fixtures. An overvoltage can cause capacitors to fail. Ensure that the transformers or drivers are properly sized and connected.
2. Line Transients
High-voltage spikes or transients can damage capacitors. Consider installing surge protectors or transient voltage suppressors (TVSS) on the lighting circuit.
3. Poor Wiring
Check the wiring connections to the fixtures and capacitors. Loose or incorrect connections can cause arcing and capacitor failure. Ensure proper grounding and polarity.
4. Fixture Defects
Inspect the fixtures for any defects, such as short circuits or damaged components. Replace any faulty fixtures as necessary.
5. Capacitor Quality
Use high-quality capacitors designed for the specific application. Check the capacitance and voltage rating of the capacitors to ensure they meet the requirements.
Recommended Actions
1. Troubleshooting Procedure
Inspect the wiring, connections, and fixtures for any visible damage or defects. Measure the line voltage and check for any transients. Replace any faulty capacitors and ensure proper connections.
2. Preventive Measures
Install surge protectors or TVSS to minimize line transients. Use high-quality capacitors and fixtures from reputable manufacturers. Monitor the system regularly for any signs of trouble.
3. Safety Precautions
Ensure that the electrical system is properly grounded and isolated before performing any work. Wear appropriate safety gear and follow electrical safety protocols.
Additional Tips: Consider using extended leads for the capacitors to reduce stress on the wiring connections. Check the temperature rating of the capacitors to ensure they are suitable for the operating environment.* Keep the area clean and free of dust or debris that can interfere with electrical connections. Flag for review