I have an interesting situation where using paralleled breakers would solve a problem. We are adding air conditioning to an older two story dorm at a private university. Presently, it is heated by electric strips but with the installation of the chiller and the necessary piiping, steam will be used for heating using the two pipe system.
The problem is getting sufficient power for the 18Ton chiller. Presently, there are two panelboards mounted side by side, each fed from a pad mount transformer across the street. These feed the existing strip heat and some miscellaneous other loads. The new chiller requires a MOCP of 125A. The above panelboards can only accommodate a maximum of a 100A feeder breaker. Neither panelboard alone could support the chiller load.
What is proposed is to add a 100A breaker in each panel and use both feeders to feed a 200A disconnect fused at 125A. Each feeder would be sized at 1/0, the minimum conductor size for paralleled conductors. Distance is something over 100 ft. I can?t see anything in the code that would prohibit such an installation. The configuration would evenly split the load between the two panelboards. Should one breaker trip or the load become significantly unbalanced, the breakers would trip on overload. The disconnect would be marked as fed from multiple sources, etc.
I have used this before in a power generator application where we used parallel 3000A breakers and it was very successful.
Any thought on this application? The alternative is to dig up the road and add an additional service, which would be quite expensive.
The problem is getting sufficient power for the 18Ton chiller. Presently, there are two panelboards mounted side by side, each fed from a pad mount transformer across the street. These feed the existing strip heat and some miscellaneous other loads. The new chiller requires a MOCP of 125A. The above panelboards can only accommodate a maximum of a 100A feeder breaker. Neither panelboard alone could support the chiller load.
What is proposed is to add a 100A breaker in each panel and use both feeders to feed a 200A disconnect fused at 125A. Each feeder would be sized at 1/0, the minimum conductor size for paralleled conductors. Distance is something over 100 ft. I can?t see anything in the code that would prohibit such an installation. The configuration would evenly split the load between the two panelboards. Should one breaker trip or the load become significantly unbalanced, the breakers would trip on overload. The disconnect would be marked as fed from multiple sources, etc.
I have used this before in a power generator application where we used parallel 3000A breakers and it was very successful.
Any thought on this application? The alternative is to dig up the road and add an additional service, which would be quite expensive.
