Need some opinions please. Went on a service call today for a hot tub (installed a year ago) that has recently started tripping the 50 amp GFCI. I found a 6/3 with ground--both egc and ungrounded conductor were landed on the ground bar in at the tub but in the disconnect I found the the egc was not attached to anything and the ungrounded conductor was capped off (looks to me to be no ground at all!!)
The tub had a sticker that stated it only required three wires. I placed the egc in the disconnect gound bar and then once I placed the ungrounded conductor in the appropriate lug on the GFCI breaker it tripped immediately. So I removed the egc from both ground bars and everything seemed fine. (I believe that the egc was occasionally making contact to the disconnect housing that was causing the tripping to start in the first place)
Then talked to the tub retailer and he tells me that the grounded conductor should be removed from the breaker and placed in the disconnect ground bar. He claimed that because there is no neutral on the tub that the GFCI breaker protects the two ungrounded conductors from ground faults.
Is this right?? It seems to me that there would be no ground fault protection if the ungrounded conductor (which in essence is the egc now) is not landed on the breaker lug instead of the ground bar at the disconnect.
The schematic only shows wiring inside the tub--not in the disconnect.
can anyone also provide any reference material in support for or against the retailers recommendation?
I am confused as to what you are talking about. Change the names of your conductors as follows and see if this might clear up what you are saying.
Ungrounded = Phase, hot, juice, live, ect. This is the conductor that carries the current to the tub.
Grounded = neutral, white, gray, common, ect. This is the conductor that the utility has grounded and the return path for any unbalanced portions of the load.
Grounding = the equipment grounding conductor, bonding ect. This the conductor that gives a low impedance path for ground faults to follow back to the source and operate the over current device.
Any time that the ungrounded conductor is landed on the grounding bar of the disconnect and everything else is installed correctly the OCPD will blow (trip).
I think that the question is: Should the grounded (neutral) land on the breaker or the grounded (neutral) bar in the panel. Answer: Land the grounded (neutral) from the tub on the breaker and use the grounded (neutral) from the breaker to the grounded (neutral) bar.
The equipment grounding (bonding) conductor should have a lug that is attached to the control panel enclosure somewhere and the equipment grounding (bonding) bar in the panel. All four wires should land on something at both ends.
Re: hot tub gfci wiring issue#57011 10/04/0510:18 AM10/04/0510:18 AM
originally posted by dp007 The only exception is that the tub notes that there are only three wires required so the bare wire has been eliminated (when wired as you indicate it immediately trips the breaker)
(2) Grounding of Electrical Equipment. Non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials. (3) Bonding of Electrical Equipment. Non–current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.
680.6 Grounding. Electrical equipment shall be grounded in accordance with Parts V, VI, and VII of Article 250 and connected by wiring methods of Chapter 3, except as modified by this article. The following equipment shall be grounded: (3) All electrical equipment associated with the recirculating system of the specified body of water
If you decide to leave a conductor disconnected it CAN NOT be the equipment grounding conductor (bare or green)
If it immediately trips the breaker then there is a ground fault some where in the system. By removing the low impedance path back to the source the ground fault is hunting for somewhere to go. Let’s hope and pray that the path it travels is not through a human being. There is a problem in the system!!!
edited to fix quotes
[This message has been edited by jw electric (edited 10-04-2005).]
Re: hot tub gfci wiring issue#57013 10/04/0503:12 PM10/04/0503:12 PM
I was giving some thought to your problem this evening and it hit me.
both egc and ungrounded conductor were landed on the ground bar in at the tub
This is a no-no to start with. The grounded (neutral) will have a lug of it’s own and the equipment grounding conductor will hit a lug that is attached to the metal of the control panel.
but in the disconnect I found the the egc was not attached to anything and the ungrounded conductor was capped off (looks to me to be no ground at all!!)
You are correct, there is no equipment grounding path at all installed this way. These people have been very lucky for the past year.
The tub had a sticker that stated it only required three wires.
This means that the grounded (neutral) conductor is not needed at the tub and can be capped in the tub panel.
I placed the egc in the disconnect gound bar and then once I placed the ungrounded conductor in the appropriate lug on the GFCI breaker it tripped immediately.
Here I ask, was the grounded (neutral) conductor still terminated in the control panel of the tub? If it was and the equipment grounding conductor was connect at both ends this gave a parallel path for the current to return and thus the GFCI did it’s job by tripping.
I suggest that the grounded (neutral) (white) conductor in the cable be left off at both ends. The grounded (neutral) (white) conductor of the GFCI installed and the equipment grounding conductor installed at the appropriate places and see if this cures the problem.
Re: hot tub gfci wiring issue#57016 10/04/0506:24 PM10/04/0506:24 PM
JW electric hit the nail on the head with the way I was thinking when I arrived on the scene "parallel path for the current to return" when both egc and neutral were landed.
Because the label stated it is a three wire set up I am thinking that I will used the white as an egc instead of as a neutral (which I will permanently mark with green)
The main issue I have is should that wire(the egc) be landed on the neutral bus in the disconnect (like the retailer instructed), the grounding bus in the disconnect or should it be landed on the GFCI breaker?
Safety is my main concern as well as comliance with section 250.
If the egc IS landed on the GFCI breaker, am I addressing both of these concerns?
I just can not get the idea out of my head that this tub will not be ground fault protected if I do not land it on the breaker itself instead of on the neutral bus.
Re: hot tub gfci wiring issue#57018 10/04/0507:21 PM10/04/0507:21 PM
If everything in the tub runs off 240 volts (no 120 used) then the grounded (neutral) is not needed. The equipment grounding conductor can land on either the grounded (neutral) or the grounding bus in a main panel. If this tub is fed from a sub panel then it will need to land on the grounding bus. In either case the white wire coming out of the breaker will need to be connected to the neutral bus in the panel
If the conductor is being used for the equipment grounding conductor it can not land on the GFCI
680.42 (C) Interior Wiring to Outdoor Installations. In the interior of a one-family dwelling or in the interior of another building or structure associated with a one-family dwelling, any of the wiring methods recognized in Chapter 3 of this Code that contain a copper equipment grounding conductor that is insulated or enclosed within the outer sheath of the wiring method and not smaller than 12 AWG shall be permitted to be used for the connection to motor, heating, and control loads that are part of a self-contained spa or hot tub or a packaged spa or hot tub equipment assembly.
The interior wiring for a spa or hot tub does not require an insulated equipment grounding conductor,
[This message has been edited by jw electric (edited 10-04-2005).]