Submersible Transformers NEC

[brother]

Is there a specific code that requires transformers (actually its a combo transformer/panel unit) installed outside underground in pit/manhole, that says its required to be submersible? Having trouble finding it in article 450 NEC 2017.

We had a situation where a submersible pump had failed and the water rose high enough to short out the transformer/panel and the receptacle. The transformer/panel in the small pit only supplies that (receptacle) pump and maybe one more down to the another very small pit.

It was my understanding because of the harsh environment that the transformer had TO be of a submersible type in an underground pit/manhole that will always see water. It was also a bad design in my opinion to even have a panel/combo in this pit and the receptacle even if its a raintight type.

 

[brother]

I think I found my answer, but would lke to hear from Mike Holt posters.

 

[tom baker]

The equipment installed needs to be rated for the environment, 110.11 and installed per mfg instructions, 110.3 B.

Its a normally dry environment if dehumidifier and the sump pump works. Replaced a lot of sump pumps
I have done a lot of installs in vaults. I would not put a trans and panel in a vault, I would put above in a large enclosure.
But, you could have two sump pumps, high level and high high alarms plus routine checks