Preferred option: Let them waste time camping it. Focus on the flag stand instead.
First, an aside: Unlike earlier Tribes games, players spawn fully equipped in their chosen armor class. Since you don't have to visit an inventory station to gear up anymore, the generators tend to be ignored in high-level play. This is a controversial state of affairs that may see some changes in the coming months.
If a third of the other team wants to have a party in your gen room, let them. Switch to Pathfinder and chase enemy cappers instead. Switch to Doombringer and plant yourself on the flag, chaingunning down anyone who approaches. Switch to Soldier and harass approaching offense in your midfield. Cappers zooming around at 200 sanics or more aren't going to care about turrets, so neither should you.
Alternate option: Switch to Brute or Juggernaut and clear out your base, but don't forget...
If there's one thing the Brute is good at (and arguably, this is the only thing the Brute is good at) it's close-quarters combat. The Heavy Spinfusor and Disco Grenades are great at taking down enemies indoors, but depending on the layout of the base and the number of hostiles, the Juggernaut's mortars may work better.
However, keep in mind that any players you kill will have respawned and skied back to your gen room in 20 or 30 seconds. With the regular repair gun, that's just enough time for you to get your generator back to 60% or so before the Raider you just killed turns the corner and blows it up again. If you don't have a Technician buddy to repair the generator for you and set up a couple turrets, you'll be right back where you started.
Personally, if I find myself in this situation, and none of my teammates are helping me set up a solid base defence, I'll just opt for option #1 above.
Best Answer
No, players never count as heavy armor.
What counts as heavy armor are: