Mike Dolt Enterprises
Mike Dolt Enterprises
User: tom_jlr, Location: Wisconsin
Asked on: Monday, May 2, 2011 at 4:25 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:52 am EDT
Question: I have four story office building, being serviced by a 1600 amp switchboard with protected by a 1600 amp circuit breaker with ground fault protection. The main tripped for the third time this year. Twice because of a faulty compressor in a roof top unit and once from a light switch.What is bothering me is the last tripping of the main. The facility maintenance man was "fixing" a switch that had become loose. He was working on it hot and was tightening the terminals (that's his story). Anyway..."poof" the whole building goes down again.Building owner is looking for solutions to eliminate the main from tripping. He was told that the GFP is doing exactly what its suppose to do. But that is not good enough, he fails to believe that a light switch can take down the whole building.
Possible Causes of Main Breaker Tripping
1. Faulty Compressor
Ensure that the compressor has been replaced or repaired. Establish a maintenance schedule to monitor the compressor's performance.
2. Loose Light Switch
Inspect and tighten all electrical connections in the building, including light switches and outlets. Consider using anti-vibration devices on loose connections.
3. Loose Terminals on Main Breaker
Inspect the terminals on the main circuit breaker and ensure they are securely tightened. Consider using a torque wrench to ensure proper tightening.
4. Damage to Ground Fault Protection (GFP)
Test the GFP to verify its proper functionality. If the GFP is faulty, it should be replaced.
5. Overloading
Check the building's electrical load to ensure it does not exceed the capacity of the 1600 amp main breaker. Consider adding subpanels or upgrading the electrical system if necessary.
Solutions to Eliminate Main Breaker Tripping
1. Improve Electrical Maintenance
Establish a regular electrical maintenance schedule that includes inspections, testing, and repairs. Train facility maintenance personnel on proper electrical safety procedures.
2. Install Surge Protectors
Install surge protectors on all electrical equipment to protect against sudden voltage spikes that can cause electrical faults.
3. Implement a Redundant Power System
Consider installing a backup power system, such as a generator or uninterruptible power supply (UPS), to provide backup power in the event of a main breaker trip.
4. Consider Selective Coordination
Selective coordination involves setting up overcurrent protection devices (fuses or circuit breakers) in a hierarchy that allows specific circuits to trip without affecting the main breaker.
5. Educate Building Occupants
Inform occupants about the importance of reporting any electrical issues promptly. Request that occupants avoid overloading electrical circuits.
Additional Considerations: It is important to understand that GFPs are designed to protect against electrical faults that can cause fires or shock. While they may trip for seemingly minor issues like a loose light switch, they are performing their intended function. The building owner should consider the potential risks associated with disabling the GFP. Consulting with a qualified electrician is highly recommended to assess the building's electrical system and recommend the most suitable solutions. Flag for review