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I have no idea what you are trying to do, but there is no way you can change 220v 50 amp to 120v 30 amp. You can take 220 volt input in the top of your circuit breaker box. Then half of one side will be 120v and half of the other side will be 120v. You can install a 30 amp fuse. You should hire an electrician.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized
IF YOU ARE NOT REALLY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
Check the MFG for the amps it uses, if it is suppose to be on a regular 20amp line, then replace the breaker with a 20amp breaker. With the 30amp breaker,it will work, but if there is a surge, you could send too much power to the appliance and fry it. Most refrigerators, are just on a regular 120v household outlet. Besides a 30amp breaker must have 10ga wire, if the wire is 12ga,it can not be attached to a 30amp breaker.
30 amp
Yes.
1.9 amps
1 amp
120v/12v 30amp power supply comes to mind.
12
there is 120V across the circuit.
there is 120V across the circuit.
Check the MFG for the amps it uses, if it is suppose to be on a regular 20amp line, then replace the breaker with a 20amp breaker. With the 30amp breaker,it will work, but if there is a surge, you could send too much power to the appliance and fry it. Most refrigerators, are just on a regular 120v household outlet. Besides a 30amp breaker must have 10ga wire, if the wire is 12ga,it can not be attached to a 30amp breaker.
30 amp
Yes.
Not directly, you would need to transform 480v circuit to 120v with a transformer first.
1.9 amps
1 amp
You are mad idiots fools
You have to replace the wire (as you are increasing the current capacity), the outlet, and the breaker. Essentially you have to remove the old circuit and put in a new one. You can't reuse parts of the old circuit as you are increasing the current capacity and they would be underrated.