An engineering study in which protective devices (i.e. relays, fuses, circuit breakers, etc.) are modeled against one another to determine their optimal settings. This is done to achieve selectivity in the event of a fault (limit affected equipment), protect equipment, and limit incident energy (protect employees).
What are the Benefits of a Coordination Study?
- Less downtime due to improved reliability
- Improved equipment protection
- Lower incident energy values
NEC requirement for:
- Emergency Systems
- Legally Required Standby Systems
- Healthcare Facilities
- Critical Operations Power Systems (COPS)
- And many other systems
Why are Coordination Studies Needed for Your Electrical Systems?
The majority of existing electrical systems currently in use have either not had a coordination study done or have not had it updated to reflect changes in the system.
This can pose a significant risk to a facility as a single fault in a non-essential circuit can take an entire building offline if the system has not been coordinated. A common
example of this is a 277V lighting ballast faulting and causing the main breaker to trip on a ground fault. In such an instance a properly coordinated system would limit the
effected equipment to that of the breaker feeding the ballast. In addition to the posing a reliability issue, mis coordinated systems can also create dangerous situations for personnel and equipment. This is due to the protective devices not being properly sized, selected (i.e LSIG, thermal magnetic, etc.) for the application, and/or set to allow for proper system operation while ensuring personnel and equipment are protected. A properly performed coordination study will yield improved system reliability, better equipment protection, and reduced arc flash hazards for personnel.