House was built in 50s or 60s, and there was a bundle of wires all grounded to the main ground lug. I removed them and began to separate to disperse them along the ground bar, and three of them are hot. Also they are a mixture of white and bare wires. Do I connect them to the ground bar?
Electrical – How to rewire this electrical panel
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Related Solutions
According to Table 250.122 of the National Electrical Code, a 10 AWG copper conductor is fine as an equipment grounding conductor for circuits with up to 60 ampere protection.
National Electrical Code 2014
Chapter 2 Wiring and Protection
Article 250 Grounding and Bonding
250.122 Size of Equipment Grounding Conductors.
(A) General. Copper, aluminum, or copper-clad aluminum equipment grounding conductors of the wire type shall not be smaller than shown in Table 250.122, but in no case shall they be required to be larger than the circuit conductors supplying the equipment. Where a cable tray, a raceway, or a cable armor or sheath is used as the equipment grounding conductor, as provided in 250.118 and 250.134(A), it shall comply with 250.4(A)(5) or (B)(4). Equipment grounding conductors shall be permitted to be sectioned within a multiconductor cable, provided the combined circular mil area complies with Table 250.122.
NEC 551.76.C (RV and RV parks) Grounded conductor not to be used as equipment ground. To me that says you need to isolate the ground and neutral and will need a rod at your site.
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Best Answer
The neutrals are hot until they're connected to the neutral bus whenever the load is connected (switched on or whatever). You have a very dangerous situation there whenever they're disconnected. You should never disconnect neutrals or grounds unless the associated hot is disconnected or the breaker switched off.
More info and explanation
In a main panel, ground and neutral are "bonded", and they share one or more bus bars. The neutrals and grounds for a particular branch circuit should never be installed together under a single screw. It is a code requirement that each neutral be terminated one per hole with no other wires. This prevents inadvertent and dangerous detachment of additional neutrals when working with a single screw.
UPDATE: Here's a good discussion on 408.21, the section that covers this issue. My interpretation is that neutrals must be individually secured, but grounds can be doubled (or even tripled) when the hardware allows. Confusion often stems from the terms "grounded" and "grounding". The former refers to grounded neutrals, and the latter to (typically) bare ground conductors.