I have a motor generator which provides me with clean power. The system is a 3-phase 120/208 feeding a 250Amp panel. Over time it has been used to feed (8) 100Amp 3-phase sub-panels. Now with spaces still available the building coordinator wants me to feed (2) additional 100Amp subs. At peak I a am only showing a total load 118-123 Amperes well below the main breaker rating. What I am trying to explain to them is that the power consumption is below, but, the capabilities are there for overloading the distribution main. Is there a code reference that addresses this situation? Looked through Art. 408, Art. 240 and didnt see anything specifically. Thanks for any guidance.
Looking for NEC reference
- Thread starter CDSJ
- Start date
- Status
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Is the generator the only source of power?
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
It is a risk to take if the existing load should grow without capacities being monitored. It is a design decision.
If you are compliant with 220.87, then there is no code violation.
If I were to plug a toaster into each receptacle in my house at the same time, I would trip the main breaker, but there is no code violation.
If you are compliant with 220.87, then there is no code violation.
If I were to plug a toaster into each receptacle in my house at the same time, I would trip the main breaker, but there is no code violation.
George, the generator only provides back up power during an outage or picks up a phase during single phasing. Thanks
Ron the environment I work in is everchanging. This problem of undersizing services and not allowing for future growth has been continuous throughout my facility. With almost 60 buildings dating back to 45' I am trying to instill a sense of projection when it comes to electricity. Thanks also.
Ron the environment I work in is everchanging. This problem of undersizing services and not allowing for future growth has been continuous throughout my facility. With almost 60 buildings dating back to 45' I am trying to instill a sense of projection when it comes to electricity. Thanks also.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
CDSJ,
I am a datacenter engineer and understand your predicament.
IT loads are relatively steady state, and a procedure to follow would be to check load readings at the panels and UPS prior to adding new equipment. Adding 20 new panels doesn't mean the load will grow.
To add any significant sized UPS, it will take a lot of capital, so most management want to use as much of the existing infrastructure as possible. I requires good monitoring.
I am a datacenter engineer and understand your predicament.
IT loads are relatively steady state, and a procedure to follow would be to check load readings at the panels and UPS prior to adding new equipment. Adding 20 new panels doesn't mean the load will grow.
To add any significant sized UPS, it will take a lot of capital, so most management want to use as much of the existing infrastructure as possible. I requires good monitoring.
- Status