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BlackTip
01/30/2016, 01:21 PM
I installed a transfer switch and an outdoor plug. The problem is circuit breakers that has AFC trips when I switch them to generator power. The circuits that power my tank are AFC.

Electric panel layout:

Inside the electric panel, there are two bars - one neutral and the other is ground. The ground bar is connected by thick copper wire, and the neutral bar is connect by very thick cable. I believe both bars are used as ground, because I can see that both bars have white and stripped copper wires connected to them.

Transfer switch layout:

There is a green wire and white wire (ground and neutral). First I connected both wires to one bar, then I connected the white wire to neutral and green to ground, then I connected the green wire only, and finally the white wire only. In all of the above combination, the AFC breakers trips when switched to generator power.

I double and triple checked the wire connections, and they look right.

Any idea on why the AFC breakers trips?

Here is the generator I have: http://www.championpowerequipment.com/products/generators/for-home/100155-7000w9000w-generator/
Here is the transfer switch: http://www.homedepot.com/p/Reliance-Controls-10-Circuit-30-Amp-Manual-Transfer-Switch-Kit-310CRK/205793178

Thanks,

homer1475
01/30/2016, 04:05 PM
Not that I have a clue, but after doing some research on what an AFCI breaker was(had no idea). They are wired slightly different and found this, it might help or not?

Are there any wiring and installation guidelines? The basic difference between installing the AFCI versus a standard thermal magnetic circuit breaker is the requirement to connect both the hot and neutral conductor to the proper terminals of the AFCI. In a circuit wired with a conventional circuit breaker, the hot conductor is connected to the breaker and the neutral conductor is connected directly to the neutral bar of the load center.

BlackTip
01/30/2016, 04:09 PM
^^ Thanks

I found the cause, but have not determined the proper solution yet. The problem is that the generator ground and neutral are bonded. One way to fix the problem is to break this bond in the generator wiring. Doing so will void the warranty and render the generator dangerous to use in a stand alone application. I thought disconnecting neutral in the transfer switch solves the problem, but it didn't.

Any other ideas?

homer1475
01/30/2016, 04:14 PM
Remove the AFCI breakers and install normal ones? Not even sure if the bus is the same or not. I know some basic electrical from working with my brother in law(Run a wire from the panel, installing a breaker, wiring an outlet, etc), but haven't come across AFCI breakers yet. Sorry.

BlackTip
01/30/2016, 04:17 PM
Remove the AFCI breakers and install normal ones? Not even sure if the bus is the same or not. I know some basic electrical from working with my brother in law(Run a wire from the panel, installing a breaker, wiring an outlet, etc), but haven't come across AFCI breakers yet. Sorry.


I don't want to remove the AFCI breakers, they are there for a reason.

bwhit1406
01/30/2016, 04:36 PM
Please describe more your connection from generator to transfer panel to house panel

BlackTip
01/30/2016, 04:46 PM
Please describe more your connection from generator to transfer panel to house panel

Generator to outdoor plug:
30 amp 4 prongs plug that is part of the transfer switch kit. It hooks to the 30 amp connector in the generator

Outdoor plug to transfer switch
10 gauge wire is connecting the plug to the transfer switch through the wall. 4 wires - red, black, green, and copper (ground)

Transfer switch to electric panel:
The transfer switch has 10 circuits. Each circuit is marked with a letter (A,B,C, etc). Each circuit has a black and red wire. Each circuit is connected to the corresponding circuit in the electric panel. For example: Heater to A, Tank to B, etc.
In addition to the above wiring, there is a green and white wire. Green is connected to one bar (ground) and white is connected to the neutral bar. I believe both ground bar and neutral bar are used as ground, because both bars have white wires and ground wires connected to them.

Thanks,

bwhit1406
01/30/2016, 05:15 PM
The neutrals and grounds mixed on the terminals should not be an issue since the neutral is required to be bonded at that point. I also dont think the grounded neutral at generator should be an issue. Can you go into a little more detail about the circuit breaker to transfer panel circuit connection?

BlackTip
01/30/2016, 08:49 PM
The neutrals and grounds mixed on the terminals should not be an issue since the neutral is required to be bonded at that point. I also dont think the grounded neutral at generator should be an issue. Can you go into a little more detail about the circuit breaker to transfer panel circuit connection?

From the transfer switch there is two wires for each connection - black and red. The red wire is connected to the power load connector in the circuit breaker, then the wire that was initially connected to the circuit breaker and removed and replace by the red (black), is connected to the black wire from the transfer switch with wire tie. This per manual instruction and a video provide by the company.

The way the AFC breaker connected in the main panel is the white wire is connected to the breaker and white looped wire coming out of the breaker is connected to the ground bar.

Utwo229
01/30/2016, 08:54 PM
Hi, I am an electrician and will try to help you here.

Firstly, you MUST only have on bonding jumper in your electrical system. That jumper must only be at your service entrance in you .

It sounds like your transfer switch is not a service entrance one. Unless the transfer switch disconnects the utility neutral, you have a ground loop because the generator has a bonding jumper too. Depending where you live and which version of the national electric code your local subscribes to, this setup is probably not legal anymore and if you read the fine print from the generator mfg. it probably says something about wiring in conformance to the national electric code.

So that is a starting point..

As for the AFCI breakers, yes they have a reason which I can explain if interested. But they can be very finicky if misfired. We will have to figure out how they are wired.

Utwo229
01/30/2016, 09:02 PM
Any sub-panel wired downstream of your main panel must have the neutrals and grounds separated on different busses. The only place you will see both neutral and ground wires on the same bus is in the main service panel where the bonding jumper is located.

So you need to retire the circuits in your transfer switch.

Utwo229
01/30/2016, 09:06 PM
See page 4 of your generator manual. Warning in lower left. You will see a note about what I just talked about with the neutrals.

Utwo229
01/30/2016, 09:27 PM
I assume you moved the AFCI breaker to the transfer switch otherwise it wouldn't get any power when the generator switched on. Did you move its neutral with it as it should have been attached previously?

As a side note, unless your AFCI is a combination GFCI/AFCI then you are not protected agains dangerous ground faults in your fish room and I highly suggest you change out the breaker for one of those.

But in the meantime, let's get what you have working first.

BlackTip
01/31/2016, 08:47 AM
Thanks for your help.

- I didn't move the AFCI breakers from the service panel, and I don't intend to.

- I don't have a sub-panel

- The warning in the manual page 4 is in regard to the GFCI built in the generator, not the transfer switch.

There is a technical bulletin her http://theportablegenerators.org/manuals/Champion/Electrical-Neutral-Bonding.pdf

That show to break this bond at the generator. If I do that everything will work, but the generator should not be used as stand alone. I want to know if there is anything I can do at the transfer switch side to solve the problem without altering the generator.

Utwo229
01/31/2016, 02:22 PM
Maybe I don't understand what oh have done.

The transfers switch transfers the power to your branch circuits from the utility to the generator. It eliminates the possibility that the generator can back feed the utility should the generator be in operation. The only circuits that will have power when the transfer switch engages are those that are in the panel on the transfer switch. So if you didn't move AFCI breakers then how do you know they don't work when the transfer switch in engage and theneneratormis operating?

As far as the electrical system in your house is concerned, unless your transfer switch disconnects the utility neutral, your transfer switch is in fact a sub-panel. And therefore, you should have no bonding jumpers anywhere except in the main panel.

Read the warning note again past the part about GFCI. Specifically "if the neutral bonding wire is removed to accommodate installation to a house..." Etc... Yes that is exactly what you must do. And yes if you do this, there are implications to the GFCI receptacles on the generator itself.. And read further about if your transfer switch disconnects the utility neutral then you don't want to disconnect the bonding wire.

With the transfer switch you have, you must disconnect the bonding wire at the generator. There is no other option. You could get a much more expensive transfer switch that disconnects the utility neutral and then you can leave the bonding jumper in place..

JonnyQuest
02/01/2016, 06:03 PM
First off I'm not an electrician but I did a lot of research before installing my own Cummin air cooled ~20 kW (17.3kW on Natural Gas) whole house generator last summer. The town electrical inspector said I did a more professional job on the installation than the contractors that do it for a living.

Attached is a link to Mike Holt Enterprises (http://www.mikeholt.com/freestuff-books.php)that has a really good article on standby generators connected to your house electrical system. See "Generators and Standby Power Systems, Rule 220.87, Articles 445, 700, 701, and 702 – Mike Holt Enterprises - Based on the 2011 NEC" Page 4

Author’s Comment: If the feeder conductors from the generator
terminate in a transfer switch that doesn’t open the neutral
conductor, the generator isn’t considered a separately derived
system [250.30 Note 1]. Figure 445–3. A neutral-to-case bond
isn’t permitted at the generator. Under this condition, the neutral
conductor from the normal power to the transfer switch, and the
neutral conductor from the generator to the transfer switch, are
required to provide the low-impedance fault current path back to
the power source. Figure 445–4

It seems like the neutral is not switched in your transfer switch (more common) and only the Xseries Reliance transfer switches do this. So your generator should not be bonded at the generator when connected to the house electrical system. However when plugging appliances directly into the generator, it is considered a separately derived system and therefore should be bonded at the generator.

By having two points where the neutral and ground is bonded you now allowed two paths for the current. One is the neutral wire and the other is the ground wire both going to the generator. By unbonding at the generator the generator frame is now grounded to the house electrical system and current will now only flow on the neutral wire. This is the same reason all subpanels must separate grounds and neutrals or the ground wire from the subpanel to the main panel will have current flowing through it because it would be a parallel path.

dread240
02/02/2016, 10:35 PM
Wish I would have seen this earlier.

They are absolutely correct that the neutral to ground bond at the generator must be broken for this application to work.

The only way around this is to change to a 3 pole service entrance switch for your 2 hot legs and a neutral. Then you can keep the bond at the generator and use the plugs on it as normal.

BlackTip
02/03/2016, 02:16 PM
I called the tech support for the generator to discuss with them whether it is OK for me to remove the neutral/ground bond or I must have the dealer do it for me. They told me that the version sold in US has a floating neutral, which doesn't make sense to me. If it has a floating neutral, then it should have worked without a problem. I disconnected neutral from transfer switch, and it didn't work.

They may have misinformed me, I am gonna have to open and inspect the generator wire connection myself.

I found this product (Neutral Switch Kit). This suppose to solve the problem without breaking the bond at the generator, but it is $100. I don't think I'll ever use the generator without the transfer switch, so if the generator is actually bonded, I am going to unbonded myself.

http://www.homedepot.com/p/Generac-30-Amp-125-250-Volt-7-500-Watt-Switched-Neutral-Kit-for-Manual-Transfer-Switches-6297/203835706

Utwo229
02/03/2016, 05:38 PM
Easy to see if it is bonded by testing for continuity between ground and natural with an ohm meter.

I am still wondering how your AFCI breakers can function on generator power if you didn't move them to the transfer switch?

BlackTip
02/03/2016, 08:44 PM
Easy to see if it is bonded by testing for continuity between ground and natural with an ohm meter.

I am still wondering how your AFCI breakers can function on generator power if you didn't move them to the transfer switch?

I never said they are functioning. I said they are tripping, which is the reason for this thread.

Utwo229
02/04/2016, 07:23 PM
I know they are not working. I am just trying to help you here.

You have one obvious issue with your setup that must be fixed before you can tackle the second issue. The first issue I think you understand. Unbond the generator neutral from ground.

The second issue is to tackle the AFCI problem. To do that you need to describe where they are located and how they are wired.

JonnyQuest
02/05/2016, 11:50 AM
Enclosed is a link (http://www.electriciantalk.com/f18/afci-breakers-generators-34626/) to a person that had a similar problem.

Try flipping the transfer switch to generator without out the generator connected, does it trip the AFCI breaker? If it trips that should rule out the generator itself causing the issue.

fishgate
02/05/2016, 12:32 PM
I had my transfer switch wired by an electrician. I know he did not touch my generator. The generator was using the supplied 4 wire service entrance box as you are using. I never had any problems like you are experience. I am not sure about that transfer switch, but my transfer switch had 2 circuits for each circuit. One to shut it off to the house and anther to turn is on for generator supply. All 16 circuits were first shut down, when any one of them was on there was a physical block that did not allow me to throw the big switch to move to generator. When they were all off, I switched the gen switch, then I switched on each of the individual breakers (16 in total).

Maybe you should get a different transfer switch?

BTW: My electrician charged me $400 but said he should have charged more like $1000. It was his first time installing a transfer switch and said the lower price was worth the lesson he got.

max6297
02/05/2016, 02:32 PM
YOu need to run a 4 wire feeder (SER cable) to the transfer panel/switch and get a separate ground bar. Separate the neutral wire and the ground wires (separate ground bar).

smmiller506
02/05/2016, 10:24 PM
Your style of AFCI breakers may trip as a safety feature if you lose power to them. Try testing that by switching off your main without switching the transfer to the generator.

You could also test your breakers by installing AFCI outlets at a different circuit on regular breakers and switching the transfer. If the outlets also trip, you have issues. If they don't, then try new AFCI breakers and the original outlets.