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Here's the written explanation I received from the property owner.

The fusebox in the picture is the way electrical installations were done up through the 50's into the early 60's. There is nothing wrong with this type installation and in some applications it is still being used today. The use of the fan is to maintain the current carrying capacity of the fuses. If the heat gets above perhaps 100 F then the current carrying capacity will be deminished by a certain amount and when the load approaches the max for the fuse it will blow at a lower than rated load. This will cause inconvenence for the tenants and lead to more replacing of the fuses.

There is no particular fire exposure with this type of electrical installation as most buildings that were constructed up to the 60's and have not converted to circuit breakers do not have any greater chance of fires started in these installations than you would have in the circuit breaker boxes but rather in the wiring on the user side which is where the vast majority of electrical fires start. When the fuse fails it will always fail in the shutdown mode in that electricity can no flow through it to the user side.

- Tommy O.

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