You can plug in as many as you want but none of them will work. An "open" circuit is an electrical circuit which is not a complete circuit and therefore electricity will not flow through it. If you mean an unused circuit,which has no load on it, then the answer is 2 ea. 5 amp devices on a 15 amp circuit and 3 ea. 5 amp devices on a 20 amp circuit. The reason for this is that any circuit is not to be "loaded" more than 80% of the OCPD (circuit breaker amperage rating.
Chat with our AI personalities