What would cause everything on the top half of a 50 amp breaker box in a travel trailer to have power but the bottom half of the 50 amp breaker have no power and not trip the breaker?

Answer 1

Answer for USA, Canada and countries running a 60 Hertz supply service.Most likely it's a poor connection between the feed cable and either the meter base or the breaker panel.

You cannot legally work on a sealed meter base but if you have a "shutoff" at the meter base, turn off power to the breaker panel, verify that there is no power at the panel then tighten the connections inside the breaker panel.

If that doesn't solve the problem, contact a qualified electrician.

To amplify a bit, your breaker box is split into two parts each fed by one of two legs of a 230/240 VAC main supply. There will be three wires and a ground feeding the box. The white wire is neutral and Black is one side of the 230/240 VAC circuit and red is typically the other. Working on a main panel is very dangerous so calling an electrician is a great idea. If your house was fed with aluminum cable it tends to creep over time and the main screw connecting the wire to the bus bar tends to be loose. There is usually a compound use to stop oxidation when aluminum wire is used. You CANNOT just tighten this wire because it is LIVE. One of the possibilities is that some older panels may be fed from a fused disconnect box where there is a cartridge fuse on each of the two "hot" legs. The disconnect handle, when turned off, will remove power from each side of the fuses so they can be replaced.

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.

Answer 2

You likely have a bad breaker. It is not unusual for 1/2 of a two pole breaker to fail.

Check the main disconnect which is actually nothing more than a larger breaker. If that's not it, check the connections at the breakers, occasionally they can work loose, especially if the trailer manufacturer used aluminum wires.