Here's my $0.03 (inflation)
There are automatic transfer switches, manual transfer switches, and TRANSFER PANELS, there are also BACKFEED BREAKER INTERLOCK kits. Automatic transfer switches and manual transfer switches interrupt an entire feeder (along the utility feeder somewhere shortly AFTER your electric meter), and substitute your generator's output for that utility feeder. Transfer PANELS are a sub-panel usually mounted near your main breaker panel, and the critical loads from your house go to breakers in the Transfer Panel, and that panel has an interlocked set of switching contacts that disconnect all those critical loads from the panel, and substitute the feed coming from your generator (like the outdoor inlet plug seen in photo above). There's several advantages to a Transfer Panel, one being that you can LIMIT the generator to driving ONLY the emergency-critical loads (well, sump pumps, furnace, etc) so that your generator won't be overloaded by something way too big (like an electric kiln, or welder, or air compressor, or your air conditioning units) when there's an outage. Then there's the INTERLOCK BREAKER KIT... this is a UL-listed/NFPA-approved device which mounts on your breaker panel, where you can add a LEGAL generator-backfeed breaker. The interlock mechanism prevents the backfeed breaker from being engaged UNLESS the MAIN breaker is disconnected... and of course, it prevents the MAIN breaker from being engaged IF the generator backfeed breaker is engaged. These mechanisms are specific accessories made BY the panel manufacturer, and once installed properly, they're totally legal. They do NOT operate automatically, and they do NOT prevent you from overloading your generator, so when you go to perform a transfer, you NEED to shut off all the circuits that are not necessary, so you don't overload the generator.
Primary power transfer switches can be pricey. Most don't realize this, but if you have a transfer switch connected between your service panel and power meter, then your transfer panel NEEDS to be capable of transferring the FULL CAPACITY of that meter and panel's capacity.. EVEN if your generator is just a fraction of the panel rating... because the transfer switch is considered an at-risk element of failure.
This changes, however, if you have a FUSED SWITCH BEFORE the transfer panel (after the meter). At that point, the transfer switch you use, is now required to carry whatever you're FUSED at... because the FUSE is now your point of overcurrent protection.
There are portable generators anywhere from a couple hundred to about 15kw, there are trailer-mounted stationary and fixed installation generators, and there are big-box generators in outdoor-rated enclosures.
There are 2 pole generators (they run at 3600 rpm), and 4-pole generators (1800rpm), then there's 6-pole generators (1200rpm). There are INVERTER-type generators that run at variable speed (based on load) and do all their synchronous AC using a fancy solid-state inverter.
There are air cooled and liquid cooled engines...
There are engines that run on diesel, others run on gasoline, yet others are fitted up for gaseous fuels (natural gas or propane), and there are 'multi-fuel' engines that will accept more than one type of fuel.
There are generators with fully automatic operation... battery start, electronic ignition, some even have fuel injection... they usually have a 'self-exercising' mode where they start themselves on a regular basis. Many of these have integrated protective circuitry through a microprocessor, and have an interface that drives the automatic transfer switch or transfer panel.
From here on, you'll find MY recommendations, and the reasons why. Others may have different opinions, but the reason for that, is simply because they're willing to make sacrifices for reasons they feel are more important than the following aspects of basic premise:
An emergency generator's sole purpose, is to protect you, and your family, and property from loss-of-power circumstances that USUALLY result from weather events- thunderstorms, ice storms, windstorms, blizzards, hurricanes, tornados, floods, the zombie alpaca-lips, and hippies wearing hip-height rubber boots carrying velvet Elvis posters and singing 'American Pie'.
A generator doesn't constitute an emergency power option... it is just one PIECE. As noted already, a method of CONNECTING that generator (which could be anything from a fancy automatic transfer switch, to just a couple extension cords pulled through the garage door)... a method of FUELING that generator (How will you STORE fuel? can you GET MORE fuel? Will your municipal gas service be cut off as result of flood or earthquake?
Personally, I would NEVER recommend a big-box-store enclosed generator. A portable? Yeah, but not one of those that mounts outside your house, like the AC unit, on a plastic pad against the back wall... and there's several reasons:
1) It's outside. A portable will be outside too... but when you need to WORK on it, you can ROLL the portable inside. IF you kill the portable, you can roll in another portable, plug it in, and continue.
2) Big-box 'wonder kits' have fancy electronics. Lightning storms kill fancy electronics, then the automatic start systems crank until the battery dies, or the unit catches fire. Now you're stuck with a dead unit... don't bother calling the company for emergency service when there's a weather catastrophe, you WON'T GET IT.
'screamers'. Two pole synchronous generators running at 3600rpm are called 'screamers', because they're howling along at 3600rpm. Go to a 4-pole machine, and that speed is cut in half. Much calmer, and usually quieter. MY generators are 6pole machines, they burble along at 1200rpm... very docile.
Liquid cooled engines last longer, withstand wider temperature range, and when idle, don't provide a wonderful little nesting place for rodents. When the air-cooled fixed-position unit fills up with nest and feces, THEN the engine starts, shoves all that into the cooling fins, you have a fire... in your generator...
Fuel... It is unwise to assume that when your power goes out, you'll be able to drive to the corner store and fill up a 5-gallon can with gasoline. it's also unwise to have ten 5-gallon cans sitting in your garage or shed... the shelf life of gasoline is terrible... especially if there's ethanol in it (hygroscopic- it absorbs water). If you're thinking diesel, remember- ALGAE. If you're constantly rotating fuel, and you have a bulk tank (like a farm overhead type) then you might be okay for a while. If you have municipal natural gas, realize that in seismically-sensitive areas, it isn't unusual for distribution networks to have lockoff valves on the municipal feeders that shut off NG when there's a good quake. IF you can have a propane bulk-tank, though... then that's a good option- it never ever goes bad.
I don't have a generator. I have FOUR. One could say it's solely about redundancy (my wife HATES power outages)... but it's also about fuel management. I don't run my BIIIG generator unless SHE wants to bake cookies, run the dishwasher, washer, dryer and air conditioning while I'd be welding or running the mill in my workshop. When we're sleeping on a cool night, I don't NEED much power, so I can run a very small prime mover and save considerable amounts of fuel. If our needs are somewhere in the middle, I use the most appropriate unit for demand.
My generators don't have enclosures, they're in a SHED... a place I can walk into, that doesn't have rain, snow, or animals coming in... it's never dark... it has more than one lighting system- one system runs totally on utility power, one system lights up the shed if ANY of the generators are running, and there's a battery-powered emergency lighting circuit powered by dedicated emergency batteries (not the generators' cranking batteries), so if we have an outage, I don't have to stumble around in there with a flashlight in my mouth.
My generators have cranking batteries, my wife can start any one of them with a pushbutton... but ALL of them have hand cranks. ONE of my generators has an electronic ignition system... but ALL of them have magnetos, which means, if the cranking battery is dead, I just need to turn on the fuel and step on the crank three times, and they'll run. Once ONE is running, the batteries on all the rest WILL charge. I've never been in a situation that left me unable to get AT LEAST ONE going.
My transfer panel is manually-operated.
My generator starting, and occasional exercise program is facilitated by Addidas... or Red-Wings, or Crocs, or KEENs. I WALK out there... into the shed, turn on the lights, turn on the main fuel valve, turn on fuel to whichever unit I choose to run, and I start the engine. Once the engine is running, I apply a light test load to get it warmed up, I watch the oil pressure, coolant temp, frequency and voltage output, and once satisfied that everything is good, I disengage the test load, step over to the transfer panel, throw the handle, then flick the switch that engages the generator to transfer panel. The starting surge is usually high (sump pumps, furnace, refrigerators all coming on), and I watch the meters just to make certain... then once it's all stable, I head inside.
Invariably, THINGS will go wrong. A generator might not start, or might not want to generate for some reason. When that happens, I simply start one of the others... and once the other is running and transferred, I wait a bit 'till the generator shed has warmed up to a comfortable temperature, then I set a stool beside the challenged unit and start troubleshooting... in a warm, well illuminated, and safe environment.
My machines have NO microprocessors... they have NO dependancy on electronics in order to start, run, and generate. There's supervisory systems that allow me to monitor output, vitals, etc., from inside the house, but aside from that, they're stone-simple.
This is in contrast to what many go through- My machines are NOT out in the back of the house, knee-deep in icy mud, in the dark, while I fumble in heavy gloves trying to take a $#it-ton of tin bodywork off a big-box screamer who'se electronic brain got fried by the very lightning strike that knocked out the utility line.
If it sounds like mebbie I've been through this... it wasn't because I owned a mouse-destroyed lightining-zapped big-box 'screamer' sitting outside in the overgrowth...
It's because my DAD bought one (I warned him)... and my neighbors bought them (I warned them)... and my boss bought one (he didn't ask me first).
My Dad's Generac sits faithfully on it's plastic platform, behind his garage, totally worthless. Fifth microprocessor control board blew out years ago, locked itself in 'cranking mode', and fortunately ran it's battery dead before it could catch fire. By that time, he'd spent 6x the unit's original cost on service calls for blown out processors.
Now I just tow one of my trailer-mounted machines down, and connect it to his transfer panel. His favorite is one of my 5kw Kohler inline fours... 1200rpm... has a carbeurator AND a gaseous mixer and demand-regulator, I can start it up running on it's 26-gallon gasoline belly tank, and while it's powering his house, I can hook up the flexible hose from his gas line to the demand reg, and once done, just off the gasoline, turn on the NG, and it's good to run for a month or more.
Oh, there's one other power distribution method that nobody mentioned... a dedicated secondary.
The Dedicated Secondary consists of a breaker panel mounted somewhere convenient, with breakers for outlets by your refrigerator, sump pump, furnace, etc... you run receptacles to those breakers, but the panel is fed from a generator plug. When you have an outage, connect your generator to the dedicated secondary panel, then go to your sump-pump, unplug it from it's utility outlet, plug it into the dedicated secondary. Do same for your fridge, furnace, whatever. Since the system is NOT connected to your utility line in ANY WAY, there's no concern with any aspect of your house power/panel/etc... it is totally separate and isolated from the utility system.
Edited by DaveKamp - 18 Apr 2025 at 10:59pm
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Riprock wrote:
