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View Full Version : Wiring 15 amp 2 pole gfci breaker for 230 v pump using 10 2 wire


Ochalus
May 19, 2014, 06:43 PM
I ran 10 3 wire from my house to a mini panel box in my shed. I bought a 240v water pump for irrigation and I already ran 10 2 wire from the mini panel box to the pump. I bought a 15 amp 2 pole gfci breaker. The breaker has spots for 3 lines in (2 hots and a neutral). I only have a black wire, white wire and ground coming from the pump. As the black and white wire are both acting as hot should I just wire these 2 wires to the load side of the gfci breaker? If I do that there will be nothing going in to where a neutral wire should go in the breaker. Is that OK? Any assistance will be greatly appreciated.

donf
May 20, 2014, 01:42 AM
Lets go back to the first code violation! Then we need to know about the cables and finally, GFCI protection is not used for a straight 240 V connection (Neutral is not used) and finally do you have correct size breakers for the mini panelboard and is the entire system at the shed properly grounded.

The feed cable from the main service panel to the "mini panelboard" has to be replaced. By code the feed into the mini panelboard must be a 4 wire cable, Black - Red - Neutral and ground.

Next, what type of cable is being used for both the feed into the mini panelboard and the feed to the pump?

How is the feed from the mini panelboard to the pump terminated at the pump site (240 V receptacle or hard wire connection to the pump)? Is there a quick disconnect at the pump so that it can be shut down for service?

At the shed, the feeder's Neutral must be isolated from the mini panelboard's ground buss. No Neutral wires can be placed on the ground buss and no ground wires can be placed on the Neutral buss of the mini panelboard.

It is required by code that you have a light outside the entrance of the structure. And finally, you need to set up a grounding system at the shed. One or two ground rods will be needed.

Ochalus
May 20, 2014, 05:10 AM
Thanks for the response. I ran 4 cable wire from my house to the mini panel box in my shed. It had red, black, white and ground. I ran awg 10 2 wire (black, white and ground) from the shed to a 230v outlet. I made a 230v plug and wired it to to the pump so I can unplug pump during winter. This pump manual says when it is run on 230v it only needs 15 amp breaker. So I bought a 15 amp 2 pole gfci breaker. The breaker has a spot for 2 loads and a neutral but I only have 2 wires and a ground coming off the receptacle. Do I not need a gfci? I do not have grounding rod in. Do you know what I have to do for that? Thanks again for your response.

donf
May 20, 2014, 05:28 AM
With respect to the grounding rods, any Lowe's, Home Depot or just about any will carry them. You need at least one 8' long copper rod, possibly 2 depending on the resistance of the soil near the shed.

Take the breaker you have back and get a standard 240 V double breaker. 240 V cannot be used by a standard GFCI breaker or GFCI receptacle.

GFCI require the use of a Hot and Neutral. It monitors the current between the black and neutral to make sure it is the same. If there is a 0.006 difference, it shuts down.

Ochalus
May 20, 2014, 07:49 AM
Thanks again for your responses. You have saved me a lot of grief. I am going to install the grounding rod. I have very sandy soil. Should I use just 1 grounding rod or 2? Also, I haven't looked into it yet but I assume a run a bare copper wire from the grounding rod to the ground bar in the mini panel box. Does it matter what size copper wire I run? Thanks again for all your help. You have very helpful responses.

donf
May 20, 2014, 08:50 AM
Okay, You want to place the ground rod near the panelboard's location.

What is the amperage of the feeder from the main service panelboard to the shed? That's what we need to know to correctly size the EGC.

The EGC should be copper, not aluminum. If the resistance of the soil is greater than 25 Ohms, you will need a second ground rod. You would place the second ground rod within 6' of the original ground rod and then connect the two rods together with a copper conductor.

Ochalus
May 20, 2014, 10:30 AM
I only ran 30 amps from my house to the shed. I think I only need 1 grounding rod ( but whatever I think is normally wrong). I will get copper. I believe I need size 6 bare cooper wire. I will put the grounding rod right outside the shed near the panel box. Does that seem right? Thanks again sir! You're the best!

donf
May 20, 2014, 10:54 AM
A 30 amp circuit requires a 10/3 w. ground cable. You never did say what type cable you used.

I'm hoping you did not use NMB (Romex) cable because you can not use that type cable in a wet location.

A #6 AWG ground cable will be fine.

Ochalus
May 20, 2014, 11:44 AM
I did use awg 10 3 wire from house to panel box in the shed and I used awg 10 2 from the shed to the pump. I did not use Romex. Thanks again! Hopefully I will have this pump running shortly.

Studs ad
May 20, 2014, 08:53 PM
A GFI (240 ac) is required for pool pumps, hot tubs etc. That run on 240 vac. Wet & damp locations aren't a bad idea to use one, especially if you have animals. Animals are especially susceptible to fault currents that humans might not feel.

If you use the GFI, the two hot legs are connected to the breaker at the breaker terminals. The neutral wire on the GFI, although the pump does not have a neutral, should be connected to the neutral or ground terminal in the panel. You do not have to run a neutral from the breaker itself to the pump if it is 240 vac.(two hots and a ground are all the pump needs)

Are you using the sub panel as a motor disconnect only? Although the term sub or mini panel may seem the same, the requirements are sometimes different. If you put a properly sized breaker in your main panel and run the correct wire size to the disconnect for your pump, you actually only need 2 hot wires and a ground to the disconnect.

Are you using the sub panel for additional purposes? Then the neutral and grounding mentioned above are needed.

A disconnect does not have to have overcurrent protection at the disconnect, but it must be rated properly and properly identified, in sight of the motor and being capable of being locked in the de-energized position. You can use a breaker at this location, but it is just redundancy, because you are providing overcurrent protection with the breaker that feeds the wire to the disconnect for the motor.

If you are creating a sub panel with spaces for additional breakers then the rules change and you are creating a sub panel and not a motor disconnect. If this is the case then the neutral and grounding mentioned above are absolutely correct.

You can place a GFI in the disconnect if you desire. As I mentioned earlier a 240 vac motor will have no neutral. In this case only the GFI neutral wire does nothing but give the 220 vac GFI breaker a ground reference. The actual GFI mechanism is dependent on the current carrying conductors for its determination of a trip condition.

A household GFI is a personal safety device. GFI's are also used in large industrial applications for other reasons and the trip setting is much higher than what would protect a human, I.E. equipment protection, but in most people's world they are there to protect human life. A standard breaker is an equipment protection device only. You can still get electrocuted on a circuit with a GFI protecting it if you get into the circuit in the right place -the GFI won't trip. The GFI is designed such that once it is installed that normal operation will protect against faults in the circuit that could be a hazard to humans. If there is no difference between the power going out and the power coming back, then the breaker will trip near its amperage rating. A GFI won't take the place of improper sized wiring.

Once you have the proper panel wiring, you can place your GFI breaker in the panel and connect it up. With power on you should be able to trip the breaker by pressing the test button on the breaker. If it doesn't trip the breaker then you have something wrong.

FYI the real difference between a 240 volt and a 120 volt GFI is the circuit in the 240 volt breaker is looking for current difference between the two power conductors and the 120 volt GFI is looking for the current difference between the power conductor and the grounded power conductor (or neutral). In theory the same current out should equal the same current coming back, if that isn't the case then that means there is current leakage that is dangerous. The big boys figure that about 5 milliamps of current or more is sufficient to stop your heart, so most GFI's are rated in this area. There are several different GFI's that trip at different levels, but for this situation it isn't an issue.

You need to decide if you are using the panel as a disconnect for the motor or as a sub fed panel before you get into ground rods and all that stuff. The extra ground rods won't hurt anything, just extra expense is all.

donf
May 21, 2014, 05:16 AM
Studs, You are correct, thank you!

I pulled the 2014 code and all 120V/240V single phase connections near water are in fact required to be GFCI protected.

So if you did not return that GFCI breaker, keep it and install it according to the manufacturer's instructions usually on the box.