I have a 250 watt heat lamp I’ve used for baby chicks before. But now my building is 100 ft away. Can I run extension cords that far and it be ok?
With certain precautions. As mentioned earlier, you need a heavy duty outdoor extension cord. I'm not an electrician so I can't tell you the minimum requirements, get the heaviest you can. I'd want it copper to get the best conductivity that I could.
Keep it dry. Anywhere it is plugged in needs to be out of the weather, either rain, snow, or dew. Water can short it out. Any fittings need to be suitable for outdoor use. If you use more than one extension cord, where you plug them together is a vulnerable point. I'd want it to be a dry point.
Amperage is more important than watts. I don't know if you have a 120 V or 240 v system so I can't give you amps. 250 watts divided by 120 volts is just over 2 amps. Everything on that system needs to be sized for maximum amperage. Wire, connections, everything. And the entire circuit that lamp is on need to be rated for maximum amps possible. What else will you have plugged in to that circuit breaker circuit for total amperage?
My coop is about 200 feet from the place I tapped into the circuit breaker board. I had a licensed professional do it according to code which was expensive. I use a heat lamp for baby chicks down there but I also wanted the electricity for other things so I put in a circuit breaker box down there that I could tie other circuits into, things like lights and a circuit I could plug other items in, like power tools.
I don't know if you are willing to spend that much money to get power to that area. I considered it a good investment.
