[swimmer]

I'm always hearing about how connecting neutral to ground in more than one place will cause parallel fault current paths that will cause the breaker not to trip during an overload or short. But it seems to me that the current through the breaker remains the same no matter how many parallel paths exist between the neutral and ground legs of the circuit. This is a theoretical question. Multiple neutral to ground connections can seriously increase my troubleshooting time.
I'm also aware of the safety issues when grounded enclosures are conducting current.

 

[dronai]

By bonding the neutral to ground in more than one place (Service equipment, or separately derived system) can cause the neutral current to travel on the grounding system.

 

[don_resqcapt19]

You are correct, multiple current paths paths have no effect on the tripping of the OCPD. All of the current flows through the breaker. Multiple return paths does not change that.

 

[brian john]

It does or can affect the operation of GFPE. Under normal operating conditions it can result in the operation of the GFPE, under a fault condition it can delay the operation of the GFPE.

It results in ground current, which can result in some power quality issues.

Additionally if you lost a feeder neutral it is hard to say what could be worse, having all the loads in series or having the neutral current pass through an accidental or intentional neutral to ground short.

 

[Meadow]

A breaker will trip. However GFI breakers and AFCIs will not function. Conduit carrying ground current can spark if a fitting gets loose, especially with an open neutral. If a piece of number 12 is grounded in a j box somewhere and the neutral feeding the sub panel gets loose or opens the number 12 will get as hot as it can without any breakers tripping.

 

[RIVETER]

I'm always hearing about how connecting neutral to ground in more than one place will cause parallel fault current paths that will cause the breaker not to trip during an overload or short. But it seems to me that the current through the breaker remains the same no matter how many parallel paths exist between the neutral and ground legs of the circuit. This is a theoretical question. Multiple neutral to ground connections can seriously increase my troubleshooting time.
I'm also aware of the safety issues when grounded enclosures are conducting current.

It will not necessarily cause parallel fault paths. It takes a FAULT to do that in an improperly wired system. However, circuit current that is flowing on the egc can be deadly to a troubleshooter.