There is no universal safe number of devices for a power strip; total load, the strip’s rating, and the circuit capacity matter. Six small chargers may draw less power than one space heater. Never exceed the marked rating and do not use a strip for appliances the manufacturer says must connect directly to a wall outlet.
Add the load, not just the plug count
Check wattage or amperage on device labels and compare the total with the strip rating. Do not assume every receptacle can carry a high-power device at the same time.
Keep high-power appliances off ordinary power strips
Portable space heaters should plug directly into a wall outlet according to the U.S. Consumer Product Safety Commission (CPSC). Portable air conditioners, microwaves, and other large appliances should likewise follow their manual and intended circuit.
Do not daisy-chain strips or extension cords
Plugging one strip into another does not increase circuit capacity and adds connections that can overheat. If outlets are permanently insufficient, the solution is proper electrical installation rather than a chain of adapters.
Heat, odor, or discoloration means stop using it
A power strip that is hot, warped, loose, crackling, or smells burned should be disconnected from a safe point and taken out of service. If the wall outlet itself is affected, do not keep testing other strips there.
Sources
- U.S. Consumer Product Safety Commission — Electrical Safety — Household electrical safety, overloads, damaged connections, and warning signs to stop use.