Having sold technology to big organizations (and not so big) for 35 years here are a few suggestions.
First off make sure you have endorsements from as many recognizable entities as you can get: UL certification, fire departments, electrical engineers and such, you can't have too many.
Next get your device installed in something, anything to prove its' viability - any reference is better than none. And this will most likely be at least partially on your dime.
Selling to big organizations is the same as selling to government; you're dealing with a bureaucracy - very rarely is there a quick sale. You will need to get as high up the totem pole as you can from the get go, else you'll be mired in an endless cycle of having to sell to people who can't make the decision to purchase. You must sell from the top down, and you must make them want it - you're presentation will have to include (in your case) demonstrable catastrophic failure of their product from a viable real life circumstance and evidence of mitigation when your device is in play (a video would suffice). Sounds daunting doesn't it? It is.
Your best bet is to partner with an organization that already has a relationship with the target organization, they know their way around the politics inside, and believe me that is paramount.
I wish you the best of luck. There is nothing more important to our economy than entrepreneurship.