I'm running my house on generator power and am shopping off grid systems. I've been using a clamp meter to check the draw on all of the fixtures / items in my house. Question. Is it possible to measure whole house draw by simply firing everything up in the house and clamping onto a hot wire of the generator 240v output cable just downstream of the generator plug? I tried it with my well pump and got slightly lower numbers at the generator than at the well pump switch.