Usually in the panels I inspect I can follow a bare copper ground wire coming off the neutral bus which then goes to the water pipe or cement floor or out to a ground rod. Today I inspected a panel in which I could not locate a ground wire coming off the neutral bus. The panel was installed in 1993. Am I missing something? Is it safe to assume this system is not grounded?
No, the ground electrode conductor could be connected in the meter base. For that mater, anywhere up to the service point but the meter base is the most likely.
I was under the impression the ground should be in the same enclosure as the main disconnecting means. Should that not mean that a combo panel with the main disconnect should have the ground?
The more panels you inspect, the more you’ll likely see (or not see) the GEC from time-to-time. Your not seeing it doesn’t mean it isn’t present in the base or elsewhere. While it’s often a bare 8AWG or 6AWG in residential services, it could also be a coated conductor, so keep looking past bare conductors only.
Remember we are In Canada, and the USA have some things different then we do .
Yes I agree the Ground should come from The Main panel, Neutral and box to the ground rod.
Also in Canada the Ground is completly isolated from the neutral after the main panel through the whole system.
I do think in The USA they are some times mixed with the White Neutral.
added ( Recommend further evaluation by qualified Person )
Roy Cooke
The NEC says the service can be grounded (where the electrode connects) at any accessible place from the service point (typically the drip loop) to the service disconnect enclosure.
The main bonding jumper, where the neutral and equipment ground connect, shall be in the service disconnect enclosure. The main bonding jumper is not the same as the grounding electrode connection.
(A) Grounding. Services supplied from a utility transformer that is grounded to the earth must have the grounded neutral conductor grounded to a suitable grounding electrode [250.50] in accordance with the following:
(1) Accessible Location. A grounding electrode conductor must connect the grounded neutral conductor to the grounding electrode and this connection can be made at any accessible location, from the load end of the service drop or service lateral, up to and including the service disconnecting means. Figure 250–51
Author’s Comment: Some inspectors require the grounding electrode conductor to terminate at the meter enclosure, while other inspectors insist that the grounding electrode conductor terminate at the service disconnect.
The Code allows this grounding (earthing) connection to be made at either of these locations.
(4) Main Bonding Jumper. When the grounded neutral conductor is bonded to the service disconnecting means [250.24(B)] by a wire or busbar [250.28], the grounding electrode conductor can terminate to either the grounded neutral terminal or the equipment grounding terminal within the service disconnect.