Electrical Problem

[Redoverfarm]

Are those two ground buss bars connected to each other? Connected thru the case/chassis?
And connected (bonded) to the neutrals?

  It would be a good idea to connect those two ground bars somehow other than through the case . . .  

   Ultimately the ground and neutral are connected to each other, (somewhere)  I would still be concerned that the breaker didn't trip when "hot" grounded to the bare wire . . .

   I see your answer after I typed this . . .


/

Not sure but I will check in the AM for resistence between the two that should tell me.

[davidj]

If I understand things correctly this is an example of why the panel ground to neutral bonding is mandated by the NEC.

Just in case anyone cares, here's one way of thinking about this (with electrical stuff, there's usually different ways of thinking about the same thing, e.g. current vs. volts, so other explanations can be right even if they're quite different!):

For electricity to work, current has to flow out through one wire and back through another.  For a useful amount of current to flow, there has to be a significant difference in voltage - say 120V - between the two wires.  What the voltage of each wire is relative to anything else, like ground, doesn't matter - it's just the difference between the two wires that counts as far as pumping out current and getting work done.  You could have one wire at 1000V and one at 1120V - you could do the same work as a regular 120V circuit (but, of course, with a much higher chance of killing someone if things go wrong!).

A neutral wire, pretty much by definition, is a return current path wire that has been deliberately set to ground voltage by a hefty bit of copper between it and ground, typically at the breaker box.  You don't have to have a neutral wire - you can have a return current path that isn't close to ground voltage, e.g. the old-fashioned 3 wire 240V circuits (black, red and green - 120V, -120V and ground).  However, when you don't tie the return current path to ground, you need a breaker on both current-carrying connectors - either of them can produce dangerous amounts of currents when they short to ground. In contrast, by tying the return current path to ground at the box, making it a neutral wire, you're pretty much guaranteeing that a short from that wire to ground elsewhere in the circuit won't result in a large current flow - if it shorts to hot, there's already a breaker in that circuit, and if it shorts to ground it doesn't really change anything as it's already connected.  Also you don't need to switch the neutral wire off to make the circuit safe - it's really no more dangerous than the ground wire because it's pretty much the same as the ground wire.  So if you don't need an overcurrent trip and you don't need a switch, you can skip the breaker in that wire, making the whole setup cheaper.  And as a bonus, then you can then make the wire be a nice safe color like white.

Most people in the US assume that you need a double breaker in a circuit if it's 240V, but that's not really the case - in other countries (and I'm guessing in commercial installations) there are 240V circuits with one breaker.  You actually need a double breaker on domestic 240V circuits because neither wire is a neutral - neither is connected to ground (and neither can be connected to ground, because the third center-tap wire from the utility already is).   Similarly, if you don't connect the return current wire to ground on a 120V circuit, it's not a neutral and there's no way it can be safe without a double breaker and the white wire changed to a red.  Which is much more work than just making sure neutral is connected to ground!