We had a recent fire in a sprinkled warehouse that caused a problem. A seperate fire pump building was located 100 feet from the warehouse building. The utility supply went to a transformer bank with utility cut outs. Then it split with one drop to the fire pump building the other drop to the warehouse. Both services were located inside. The fire in the building got above the sprinklers. The fire was near the service equipment in the building. Because they couldn't get to the service the only other place to shut off the power to the building was at the transformer. If they do that it drops out the fire pump. For years I have inspected installations where the building and the fire pumps are from the same transformer bank. They comply with the Code. But.............. I never thought about it but that is where the utiltiy usualy cuts power during a fire. Seems like a waste to seperate everything when it all comes from the same transforemers. I don't see a solution, just a heads up that that sprinkler might not help that much after all.
Look, we can only do our best, and try to address the most expected risks. You can't make anything proof against every eventuality.
With the fire out of reach of the sprinklers .... I wonder if there was a fault with the sprinkler design .... I have to ask what good then pumps would accomplish even if they had continued to operate.
Many times the fire loading exceeds the sprinkler design. The K Mart warehouse burned to the ground several years ago because of this. Buildings need to be inspected after they are filled by a fire protection engineer to see if additional protection is needed. Sometimes sprinklers need to be installed on the shelving. A pallet of camping fuel or lots of sawdust (pressboard) furniture can quickly overtake a standard sprinkler system.
The fire started in a motor home. The wood paneling and L.P. gas inside finally blew out of the home when the windows went. The fiberglass outer shell kept the sprinklers from reaching the fire. Once it was outside the vehicle it went clear to the roof, above the sprinklers. WestUP.S. My oldest brother had just been put in charge of construction / buildings for K-mart (East coast) when they lost that warehouse. He said that the steel sprinkler pipes were melting while still discharging water.
As a utility Meterman, I have voiced my opinion against feeding the fire pumps from the same transformer feeding the building. I have been told, that this is code compliant & per spec, but that does not make it right. (One customer told me he was only installing the fire pump for the insurance discount, because his building would never have a fire...)
I know if we respond to a building fire, the first thing we do is pull the cutouts to deenergize the building. This is required by the local Fire depts, to eliminate the risk of a Firefighter being electrocuted.
The best fire pump install is a free standing building fed from a different transformer, we have a few of these in our area. They are more expensive to install, but it is the best way to go.