Typically a washing machine and gas dryer don't use a motor larger than 3/4 hp, and other than the timer, they don't typically have much of an additional current draw.
Most 3/4 hp motors pull about 6.5 amps, putting the total current load of both devices at 13 amps.
You shouldn't have trouble putting them both on a single 20 amp circuit, provided that there are no other devices on the same breaker, AND provided that the washer and dryer do not draw much more than estimated.
Understand that all manufacturers have their own idea of what the perfect washer and dryer should be like, so you may need to verify the current draw of each device before making assumptions.
And understand that the current load on a breaker should not exceed 80% of it's rated capacity, meaning that the total current draw of the two devices shouldn't exceed 16 amps.
This is not a good idea. The washing machine current will surge when motor is started. a 20 Amp dedicated circuit is recommended for a washing machine.
No, you should not install a 30 amp circuit breaker to a machine which normally requires a 20 amp supply. The circuit breaker is protecting the wire to the machine. That wire is likely only rated for 20 amps, (# 12 awg). Therefore, a 30 amp breaker could allow too much current to go through the wiring to the machine and cause the wire to burn down. Replace the 3 phase 20 amp breaker with the same amperage breaker.
If you have 100 amp wire, you can use it for a 60 amp circuit, or for any circuit of 100 amps or less. But if you have a 60 amp circuit, 60 amp wire is thinner and cheaper than 100 amp wire.
Yes, if properly wired a 20 amp circuit is a great circuit for an 18 amp appliance. Properly wired means you've used 12 gauge wire or larger and the circuit is protected by a 20 amp breaker or fuse and all connections are secure.
80% of the rated circuit. 10 amp circuit is 8 amps, 20 amp circuit is 16 amps, etc.
This is not a good idea. The washing machine current will surge when motor is started. a 20 Amp dedicated circuit is recommended for a washing machine.
Check the nameplate rating on the door or door frame of your washer, it should tell you the amp rating or the kw rating of the machine. If it only has the KW rating of the machine, simply divide the KW rating by the voltage of the receptacle and it'll give you the current (ampere) rating. Typically, a modern washing machine will draw approximately 7-12 amps. However, anticipate a higher amperage when starting the machine as the machine will draw 1.5X the rated current to start the machine (starting current). Regardless of the amp rating, the NFPA-70 (National Electrical Code) requiresa 20 Amp fuse or circuit breaker; and the circuit for the washing machine must be on its own, dedicated circuit.
Yes
No, you should not install a 30 amp circuit breaker to a machine which normally requires a 20 amp supply. The circuit breaker is protecting the wire to the machine. That wire is likely only rated for 20 amps, (# 12 awg). Therefore, a 30 amp breaker could allow too much current to go through the wiring to the machine and cause the wire to burn down. Replace the 3 phase 20 amp breaker with the same amperage breaker.
If you have 100 amp wire, you can use it for a 60 amp circuit, or for any circuit of 100 amps or less. But if you have a 60 amp circuit, 60 amp wire is thinner and cheaper than 100 amp wire.
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.
Yes, if properly wired a 20 amp circuit is a great circuit for an 18 amp appliance. Properly wired means you've used 12 gauge wire or larger and the circuit is protected by a 20 amp breaker or fuse and all connections are secure.
80% of the rated circuit. 10 amp circuit is 8 amps, 20 amp circuit is 16 amps, etc.
A dedicated 20 Amp circuit wired with 12/2 wiring an a 20 amp breaker.
7 on a 15 amp circuit and 9 on a 20 amp circuit.
15 amp outlet on a 20 amp circuit.
A 20 amp circuit with #12 gauge wire will work in any event but if the nameplate recommends a 15 amp circuit then #14 gauge wire on a 15 amp circuit is sufficient. In either case you will have a double pole breaker and your equipment may not require a neutral. Always run a grounding conductor.