Is it acceptable for the neutral and ground wires to be on the bus bar in the box. I've never seen this setup before and keep popping the circuit breaker even on small loads.
In the main panel where the power comes in from the outside, the ground and neutral are to be connected. That is the only place where they can be. If you have any sub panels down stream from the main box, the ground and neutral must not be connected as it is a very hazardous condition. If you have a fault that trips the breaker, it could be a bad device or damaged wiring in the walls, etc. I had a raccoon family that enjoyed munching the wires for our back porch. Tripped the breaker like you have going on.
If it is a GFI, and the load is an induction load, like a motor, the back EMF can trip it for no good reason. A good example is the little chest freezer at the BBQ pit on the patio. Code requires a GFI on any outdoor wall socket. The motor in the compressor can trip the GFI with nothing wrong.
If it is a standard breaker and resistive load like lights, bad breaker or an intermittent short. A meg meter can point out high resistance shorts to ground/neutral in any case.
The breaker substitution is an easy, inexpensive, and quick diagnostic. At worse, you have a spare breaker. Don't know how old the panel is, but if it is a Square D, the "regular" one is the "QO". If it is newer, it will be a "HOM" (homeline). They are not interchangeable, but in either case, Lowes, if you have one nearby has either, plus some for old obsolete stuff like "Zinsco".
Just remember: No hands to ground, one hand in the panel.
In the main panel where the power comes in from the outside, the ground and neutral are to be connected. That is the only place where they can be.
Not exactly true. You bond at the first point after the service (meter) which in a residence is usually the panel. However, if you have a backup generator with a transfer switch you would bond the neutral and ground there and isolate the grounds in the panel. Furthermore, if a sub panel is located in a detached garage then you either have to separate the neutrals and grounds if you pull the ground from the main panel or drive a ground rod and connect (bond) the neutrals and grounds together.
(Message edited by ferris von bueller on June 18, 2016)
The motor in the compressor can trip the GFI with nothing wrong.
This was true when ground faults first came onto the market but improvements in design of both GFI's and freezers/refrigerators has basically eliminated this issue. Arc fault breakers used to nuisance trip, too, when they first came onto the scene. In fact, staples that are used to secure the romex can trip them if they didn't have the plastic shield
I'm going to split the circuits and add some breakers.
The problem NOW is that they're Pushomatic and super pricey to buy at like $60/each. Plus I've read that they weren't the greatest. At this point, I may ask the land lord to put in a new fuse panel since they are so outdated.
I'll probably swap breakers with another one and see if it goes with the break or keeps doing it.
See if this works . . . . this is working on a DEAD 345kV with a live circuit on the other side of the tower. You can see now why it's important to know what you are doing and what you are touching. I've had some interesting incidents this summer. Fortunately I've got some of the best in the business, including Geoff, who you see on this clip. It this works . . .I'll leave it up for a couple days.
If you are completely out of things to do and have time on your hands . . .here's a montage (condensed from the 40,624 pics I took on the project) to give you a sense that I really have a "day job".