Emergency Disconnection Means

[dlbarker2]

In the process of reviewing the 60% design of a large processing facility (5 to 6 MVA peak demand), our consultant has shown an "Emergency Power Cutoff" push botton in the Utility Annex (separated from the main building by about 250 feet) for killing the double ended 13.2 kV - 480 volt substation, and the double ended 13.2 kV - 4160 volt substation. He has said they have used this kill switch on previous projects to allow the fire department an easy means of securing power. I don't want this switch, because we're intending to use the dual primary 13.2 kV with an automatic transfer function to provide the emergency power system for the building avoiding having to use a separate 400 kW generator (There are 2 - 3000kW generators that backup the entire facility, but won't meet the 10 sec rule for emergency lighting). Also, if this switch is used to secure all power the large fire pump would have to have its own 13.2 kV - 480 V transformer. The question is, how does the fire department expect to secure power for this type of facility, and are the "normal" mains and disconnects adequate?

 

[bdarnell]

We have had this same issue come up in a couple of projects that we did in New Jersey. The local fire authority requires an emergency shutoff to be located in the fire pump room. We shunted the mains on (3) 4000 amp pieces of gear to accomplish this.

And yes, we did have to have a separate 12.47-480 V transformer for the fire pump. Since technically the "main" is in the substation, we would not have complied with 695 and NFPA 20.

Can you argue that a non-orderly shut down would create a potential hazard or damage to process equipment ?