Grounding Question

Hey guys

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?

Thanks
Craig

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.

This is the allowance in the USA under the NEC…

http://www.mikeholt.com/onlinetraining/page_images/1113854601_2.jpg

(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.

(5) Load-Side Neutral-to-Case Bonding. A neutral-to-case bond cannot be made on the load side of the service disconnecting means, except as permitted for separately derived systems [250.30(A)(1)] or separate buildings [250.32(B)(2)] in accordance with 250.142. Figure 250–52 Author’s Comment: If an improper neutral-to-case bond is made on the load side of service equipment, dangerous objectionable current will flow on conductive metal parts of electrical equipment in violation of 250.6(A). Objectionable current on metal parts of electrical equipment can cause electric shock and even death from ventricular fibrillation. Figure 250–53(B) Main Bonding Jumper. An unspliced main bonding jumper complying with 250.28 must be installed between the grounded neutral terminal and the metal parts of the service disconnecting means enclosure in accordance with 250.24©.

Again…courtesy of Mr. Holt…

8AWG is not allowed.

Wrong it depends on size of service and age .
Number 8 was allowed on older systems.
Roy Cooke

Roy

Thank you I may be wrong I will try to verifiy this.

Roy is correct.

#2 copper and below MAY use a #8Awg.

Thanx Roy