# Inlet Advise



## seand43 (Oct 11, 2014)

Hi Everyone,

New to the forum and portable generators in general. I just bought a small 3100W Champion Inverter. I mainly need it to run my furnace in a power outage in the winter but would also like to be able to run a fridge and lights, one at a time. The inverter has a twist lock L5-30 receptacle on it. So I thought for convenience I would intall an inlet box on the outside wall to my mechanical room and just switch the furnace over to a plug. What I didn't realize was finding a weather tight inlet box in a L5-30P configuration would be harder than finding a unicorn. Lots of L14-30 in that configuration and conntek makes a L5-30 to a L14-30 adapter cord. I was also toying with going to a transfer switch to my panel to take advantage of the breaker protection. I really have no idea which is the best option so if anyone has some advice, I would appreciate it.

Thanks

Sean


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## SonnyT (Sep 20, 2010)

talk to a electrician that knows your Codes for the area.


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## aandpdan (Oct 8, 2012)

The easiest way to connect a 120 volt generator on your 240 volt house is to make up a cord that will connect to the generator, L5-30 and the other end put an L14-30. Just tie both hots on the L14-30 to the single hot lead. 

You will need to exercise caution if you have any multi-wire branch circuits. Basically it is two 120 volt circuits that share a neutral.

To connect to the panel, put an approved L14-30 inlet on the house and use an interlock. If you can find one from the panel manufacturer they are usually very inexpensive compared to a transfer switch or transfer panel. OEM they are also UL approved. Interlockkit.com is a pricier, aftermarket, option especially if you can't find an OEM.

With an interlock, you can apply power to any circuit in your house. The advantage is you can run anything without an extension cord BUT you need to be careful managing those loads so as not to trip the generator breaker.


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## Waypoint (Jan 28, 2014)

I did something similar, Reliant 6-way transfer switch and inlet box kit from Home Depot. I use a Honda EU3000is inverter similar to your Champion w/ the same L5-30 outlet. I run an L5-30 cable from the generator, then a Conntek adapter to plug it into the outdoor inlet box. The 6 circuits wired to the Reliant transfer switch are my central heat (natural gas hot water baseboard), fridge, kitchen plugs, bedroom plugs, garage, and basement. It works very well, we live like kings during outages. Beware the small gas tank on your Champion...the Honda holds 3.5 gals and will run all day with plenty left over.


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## seand43 (Oct 11, 2014)

Thanks for the replies. I was going to go into a transfer switch but for now I decided to just get it so it will work and then look at a transfer switch later. I did find a L5-30 in a weather tight box so I was just going to wire it direct. Inverter to an inlet box to a receptacle in my mechanical room (furnace, water heater but no electrical panel, it's in the garage). I am going to wire the line going to my furnace into a device box and a single receptacle and put a male plug on the furnace. This will meet code because it will still be the only device on that line. 



aandpdan said:


> You will need to exercise caution if you have any multi-wire branch circuits. Basically it is two 120 volt circuits that share a neutral.


My furnace has a double pole 15 amp breaker but there is only a 14/2 wire running to it. Is this what you are talking about? Are both lines hot? If so, how do I run it direct to the generator? I checked the furnace (natural gas) and it's 120V single phase 12 amp max so I thought I would have no trouble powering it with the generator. So I'm not sure why the double pole breaker.


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## Waypoint (Jan 28, 2014)

Sounds like a solid plan. We've improved incrementally also, getting a little better after each big outage. Started w/ just the inverter gen and a Rubbermaid box of extension cords. After the 2011 snowstorm 5-day outage we added a transfer switch. After Sandy in 2012 we added a doghouse and outdoor inlet box to keep the generator dry. Next project might be converting the gen to run on NG.


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## Waypoint (Jan 28, 2014)

And I'll urge caution against a breaker panel interlock kit when running a single-phase generator w/ both hots tied together. Any 2-phase appliances will not enjoy this if their breakers aren't shut off.


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## aandpdan (Oct 8, 2012)

Any 240 volt appliance just won't work if you tie both hots together but it won't damage the appliance. There is 0 volt differential between the legs.

A multiwire branch circuit shares a neutral. Why your furnace is wired as it is with a double pole breaker, I don't know. Can you post a pic of the wiring?


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## seand43 (Oct 11, 2014)

Thanks Waypoint and aandpdan for the responses. I have figured out the double pole issue. The electrician ran a 3 wire from the panel into a receptacle behind the washing machine. It’s on it’s own line and the furnace is on it’s own line. I don’t know if it’s code when you do this that you have to use a double pole breaker rather than two singles but that’s what it is. If and when I go into the panel with the generator. I will be sure not to try powering anything 240V.


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## seand43 (Oct 11, 2014)

Waypoint, have you looked into the NG conversion for your generator? Is it expensive?


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## seand43 (Oct 11, 2014)

aandpdan, this receptacle and the furnace do share a neutral. This is what you are talking about when you say multiwire branch circuit. I was reading about a double pole breaker being code when running a multiwire branch circuit but there is an amendment to this code in Canada. You can have 2 single pole breaker if the circuit is not 240V or a split receptacle and the 2 breakers have to be on opposite poles so that the neutral current is not doubled.


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## aandpdan (Oct 8, 2012)

Correct SeanD, you are describing a multiwire branch circuit. As you've described it is installed correctly with the double pole breaker.


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## Waypoint (Jan 28, 2014)

seand43 said:


> Waypoint, have you looked into the NG conversion for your generator? Is it expensive?


There's a shop in South Plainfield NJ that advertises heavily and has a great reputation. $299 installed and they do the mixture tuning on NG as well as propane, so the engine doesn't run lean and burn a valve or piston crown.


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## seand43 (Oct 11, 2014)

So everything is done. I have power to my receptacles but it's showing an open ground. I can drive in a grounding rod but can you bond it to a copper waterline? Also, I'm thinking about putting in a 40 amp Ammeter with a current transformer. Has anyone done this or had some experience with it?


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## aandpdan (Oct 8, 2012)

Correct me if I'm wrong but is this how you wired it?

You ran #10 wire into the breaker box shown. You have the hot wire tied to both breakers. From the other side of each breaker you have a wire leading to the hot terminals on each receptacle. You also have a wire from each receptacle connecting to a neutral bus in the breaker box?

You can't share the neutral here because you're running 120 volts.

The ground, where is it connected? It goes back to the generator, correct? Is there a neutral/ground bond in that breaker box?

From looking at the schematic on the generator it appears to be a "floating neutral." This would explain the "open ground" message you are getting.

Test the ground at the generator. I'm assuming you're using the little plug in tester. Just put it directly into one of the 120 volt receptacles on the generator.

A ground rod won't fix it.


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## seand43 (Oct 11, 2014)

Thanks aandpdan for the response. I will answer your questions in the order they were asked. Yes, that is how it was run. Each receptacle has its own neutral so the current is not doubled. I did not share a neutral. The ground does go back to the generator. The neutral bar is isolated in the box. The generator is a floating neutral. I tested the generator with the plug tester at the generator and it shows an open ground because of the floating neutral. I grounded the ground terminal on the generator and it shows the same. I was just trying to ensure it was well protected by a good ground. I think what you are telling me is that grounding the breaker box would not serve any purpose because of the floating neutral. Thanks again for your help and advise.


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## aandpdan (Oct 8, 2012)

seand43 said:


> The generator is a floating neutral. I tested the generator with the plug tester at the generator and it shows an open ground because of the floating neutral. I grounded the ground terminal on the generator and it shows the same. I was just trying to ensure it was well protected by a good ground. I think what you are telling me is that grounding the breaker box would not serve any purpose because of the floating neutral. Thanks again for your help and advise.


I didn't see a GFCI on your generator. 

You NEED to bond the neutral/ground somewhere. Right now with a floating neutral if there is any fault there is no return path.

For example: 

With floating neutral: You a drill with a 3 prong cord. Inside the motor, the hot lead touches the metal case. The drill will keep functioning but now the drill itself is "hot." If you have multiple devices, maybe you are using a power strip, the case on any of those other devices is now "hot" as well. There's a bare spot in one of the cords, on the neutral wire. You grab it. You'll get shocked or worse. 

With a neutral/ground bond: You are using a drill with a 3 wire cord. Inside the motor, the hot lead touches the metal case. The breaker will trip and the motor will stop. That's it. 

OR, you grab the cord with the bare spot. Nothing happens.

Bond it at the generator. That's the BEST solution. Make an adapter to plug into one of the 5-20r's. Just take a 3 prong plug and run a wire from the ground to the neutral terminal. There is no connection to the hot terminal. When you plug it into the generator you complete the neutral/ground bond.


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## seand43 (Oct 11, 2014)

What is the advantage of a floating neutral? Sounds like a recipe for disaster. I believe I can remove the neutral isolator and just bond it in the breaker box? Should I run a ground out of the breaker box to a grounding rod as well? Thanks


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## aandpdan (Oct 8, 2012)

In your case, since this panel is not connected to anything else in the house, you could put the bonding screw into the panel. It wouldn't hurt to label the panel, so you or the next guy down the road, knows that it is bonded. Or make up the adapter I described.

Again, a grounding rod is not the answer. An equipment ground (EGC), the ground on the furnace is not the same as a grounding electrode conductor (GEC) - the rod in the ground. 

An EGC provides a low impedance fault path - so the breaker trips in a short. A GEC is a high impedance ground - basically used for lightning protection in your home.

If you are connecting a generator to a transfer switch/panel/interlock then floating neutral is the way to go.

Some modern furnaces will not work without a neutral/ground bond.


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## seand43 (Oct 11, 2014)

Thanks so much for the help. I have a pretty good understanding of this stuff but dealing with a floating neutral is a first for me. There is no tone or sarcasm with my next question I am just picking your brain. I am wondering why you are cautious about bonding it in the breaker box because even if it's someone else using this, if they are going to use it to power stuff in the house, will it not have to be bonded? The only way to get power to this circuit is through the L5-30 plug in the inlet box outside. Is there a potential problem created by bonding the neutral in the box?

When I do bond it, will my tester show a good ground and I will be good to go? Is there anything else you would recommend?

The only reason I was going on about a grounding rod was because that is what they recommended when I was reading the manual so I thought that was the issue. To be honest I don't get how the generator is grounding the circuit so I was just trying to cover my bases.

Thanks again for the help! I really appreciate it!


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## aandpdan (Oct 8, 2012)

My thought is that if someone else comes along, with a different generator that is N-G bonded and uses your inlet, they wouldn't have the double N-G connection. That's all.

When you do bond it yes, the tester should show a good ground.


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## seand43 (Oct 11, 2014)

Got it. I will label the box. Thanks aandpdan for all your help. I really appreciate it. I might try a current transformer and an ammeter later.


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## seand43 (Oct 11, 2014)

Works great aandpdan, the inverter has an economy mode which I tried starting the furnace up in. The generator barely complained on start-up. Thanks again for the help!


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## aandpdan (Oct 8, 2012)

Glad to hear it. Thanks!


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