I just bought a RIDGID 6800 6800 Watt Generator - RIDGID Professional Tools. Mainly for power outages as well as some onsite home projects/ power tool work. I'm planning on keeping and running it in my 12'x12' Barn shed which is about 60' from the house. I will be getting a transfer switch installed with an external plug near the service entrance to the house.

I have about 8' of flexible exhaust pipe and a small car muffler. The original flange/spark arrestor are insufficient to support the two inch pipe I attached to the Genny' muffler outlet with JB weld so I'm having another one fabbed to the same spec but thicker with the 2" pipe welded that will provide support for the flexible pipe setup.

My dilemma is that I'm not sure whether to run this exhaust setup through the shed wall at the top or the bottom. There seems to be conflicting theories about condensation collection and corrosion versus the heat dissipation and noise dispersal provided by height. I know I have to be careful about correct routing on the inside by hanging the pipe away from the wooden walls using hangers etc (Actually I'm going to line those areas with some heavy gauge cooking foil to deflect heat as an extra precaution) So whats your thoughts. High or low?

 

I personally would pick the straightest path thus having the least bends, strictly from a flow perspective. That's why I am exhausting the 15kw Generac out the side wall of the "generator hut" I am almost done building. Here, you can see the exhaust pipe in the back of the picture going through the wall:



I have the exhaust on a slight downward slope and I did that thinking any accumulated condensation would maybe just come out on it's own due to gravity, but then I realized generac has the oval muffler mounted on the narrow side so moisture is going to collect in the muffler anyway.

If you're using exhaust tubing that's rust resistant (stainless!) then if the horizontal portion is heading slightly downhill, the moisture will collect at the lower end moreso than the higher end. When you start the generator the next time, it will be blown out.

My exhaust "end" is just the factory installed generac spark arrester cone and the retaining collar relocated to the end of the conduit outside. Nothing fancy or particularly clever.



I used 1-1/4" ERW conduit because I had a lot of it leftover from various other projects, so as a no-cost option I'm giving it a try. I ran the generator for an hour non-stop, and while the conduit was way to hot to touch, I didn't see any discoloration of the coating and the "pipe thimble" I made out of electric box parts was only somewhat warm. I could touch it after the hour no problem, so it wasn't collecting that much heat. I was worried the hot exhaust might ignite the side of the shed - plywood or clapboard - but at least for the hour I ran the generator, not even close to being a problem.

A friend of mine who housed Onan diesel in his shed put a "T" in the exhaust system just before the bend that goes vertical and eventually through the shed roof. The exhaust blows across the top of the "T", and the leg of the "T" is normally closed with a large ball valve - which is opened to allow accumulated water out. He also has a rain cap on top of the exhaust.

I don't know if any of that helps...

 

Thanks for the pics. That's really helpful. I like the idea of a dedicated hut. Pity I already bored a hole in the floor of my shed to run the cable and ground through. I'm thinking of surrounding the unit with concrete block and putting it on a platform of sorts to absorb vibration.

 

Originally, I was going to put the generator in the 10x12 garden shed I built last spring, however there was too much "stuff" in the way to get conduit back there. Huge trees and roots, a cement pad from the old shed, a fair portion of my patio is in the way (pavers on top of a 2' thick concrete slab), etc. So building a dedicated "generator hut" on the other side of the house was just easier as nothing was really in the way except a couple of half-dead shrubs that I've been meaning to remove anyway.

 

My unit is 75' from the house. I'm wondering what gauge cable to use to the transfer switch to avoid voltage drop

 

Wire gauge depends on the amperage. How many amps is your generator capable of?

My generator has a breaker limiting output to 50A, which feeds an in-hut panel that splits that off to power fans, the light, and a 40A breakered feed to the transfer switch inside, so the "big feed" to the house is limited to 40A.

I used 55A capable 6 awg for reasons of overkill - less resistance in particular.

 

There are 4 x 120V 20 amp and 1 x 120/240 30 amp. But the handbook says "
Rated Voltage........................................... ...........120V/240V
Rated Amps.............................................. ........ 56.7A/28.3A
Rated Output............................................ ...............6,800 W
Maximum Output............................................ ........8,500 W
Rated Frequency......................................... ................60 Hz

I'm definitely an overkill kind of guy. Better to have it and not need it than need it and not have it.

I'm finding it difficult to track down lower gauge cables.

 

For 30A at 75' I'd run 8 ga so the voltage drop is less than 3 volts. 10 ga would give you a 5.30 voltage drop.

Since digging a trench, laying conduit, and fishing wires is a pain in the butt, you might consider running 6 ga because then you have more than enough room to jump to a generator twice the size without having to fish new wire. Simply change the 30A generator port to a 50A unit and you're done, assuming your transfer switch is rated at or above 50A as well.

Any electrical supply house will have the wire you need, as does home depot and lowes. HD and Lowes sells spools as well as by the foot. You want to use wire that's wet rated such as THWN to cover your butt in case the conduit gets cracked and water gets in.

I ran one high power 240V circuit from the generator hut to the house, my transfer switch switches the whole 240V, then in turn feeds a sub panel that splits off to the various things that need to run on generator - two racks of server equipment, sump pumps, the fridge, and the furnace, and one outlet in the dining room which I intend to use for plugging in a floor-standing lamp so we can walk around the first floor without flashlights.

This beats running multiple extension cords through an open window and moving the fridge back and forth to plug it into one of the cords. We did that for years and while we were very careful not to get tangled in long extension cords it was inevitable that my boy, or the dog, or both, would get their legs caught.

 

I won't be digging any trenches. My plan is to have an external socket near the service entrance running from the transfer switch which I can plug into as the need arises. That way I get to disconnect my cable and transfer switch and take it with me if and when we move house.

 

So, you're going to have a 75' cord from the generator to the house? That's a long wire to unravel and drag across the yard!

I had the same concern, regarding what happens if I move. When I installed the transfer switch, I left more than enough wire to connect directly to the subpanel, so I can take it with me leaving the $25 subpanel.

I can take the generator too, just by putting the wheels back on and ragging it out and across the lawn.

 

That's no big deal for me. From outage to standby power will be no more than 10 minutes.

 

Whatever works for ya

I just remember cords all over my back yard and the hazard that was while carrying gas cans around in the heavy rain.

That's partly why I hard-wired everything, despite the extra work involved. Now my "go on generator" process is pull choke, push start, push in choke, go buy gas.

I'm working with a PWM server I'm hoping is strong enough to actuate the choke, so I can start the generator from inside the house with a controller. Then my process will be "Oh, the powers out, neat, the generator started itself!" then go buy gas lol.

 

Cable wont be a problem. I have a gas storage area which is in a different area from where the cable will be. Thanks for all your responses. They have been really helpful