Timeline for Does requirement for using transfer switch with backup generator depend on power rating?
Current License: CC BY-SA 4.0
Post Revisions
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 15, 2023 at 17:01 | comment | added | P2000 | @RussellMcMahon thank you. I am quite active in DIY and for this question I wanted a EE/circuit perspective, which I have now. I'm all for leaving it here. I think the source/ref was poorly written. This is one of those areas like "grounding" where DIY begets safety, code and bonding answers, and here in EE we get a more thorough network stability perspective. | |
| Jan 15, 2023 at 10:10 | comment | added | Russell McMahon♦ | P2000 - it has been suggested that this question be migrated to DIY, If that happens you will lose any existing comments and the 1 answer will not transfer. I could arrange migration but I suspect it will not get a better answer. BUT I may be wrong. | |
| Jan 15, 2023 at 10:08 | comment | added | Russell McMahon♦ | re " ... If your generator is above 5,000 watts, you will always need a transfer switch for safety reasons and ease of use. ... " --> The term TRANSFER switch suggests switching between two optional sources - here mains or generator. When the application is generator only it is not possible to TRANSFER the connection. A Transfer Switch then simply becomes an isolation / cutoff / safety switch - which may well be what they had in mind. | |
| Jan 13, 2023 at 16:10 | comment | added | P2000 | those of you VTC, care to provide a comment explaining? Power EE, including utilities and generators is within scope. We often get questions asking for insight about something unclear or ambiguous in a paper or manual or data sheet. | |
| Jan 13, 2023 at 16:05 | vote | accept | P2000 | ||
| Jan 12, 2023 at 22:07 | review | Close votes | |||
| Jan 28, 2023 at 3:01 | |||||
| Jan 12, 2023 at 21:31 | comment | added | P2000 | @mkeith I have that impression too, and you only need a transfer switch if at least one of the following is true: a) you want automatic transfer and/or b) you want to feed into the existing wiring serviced by utility. The power rating has little to do with it, although feeding into house wiring implies a high rating. | |
| Jan 12, 2023 at 20:35 | comment | added | user57037 | The article is written for a technically unsophisticated audience who want a simple rule to decide if they need a transfer switch. As far as I can see the article does not and does not claim to derive its authority from the electrical code. If your generator can be connected to your breaker box, then code requires a transfer switch as far as I know. I don't think there is any other legal way to do it. | |
| Jan 12, 2023 at 20:22 | comment | added | Ben Voigt | @P2000: You don't wire in a generator without a transfer switch. Full stop, doesn't depend on power rating. The only place power rating comes in is "can you reasonably unplug your loads from wall sockets and plug them into outlets on the generator?" which for large number of small appliances would be very annoying, while large loads such as central HVAC may be permanently wired and not capable of being unplugged/replugged. | |
| Jan 12, 2023 at 19:16 | comment | added | P2000 | @ChrisKnudsen ah ok good point! so the logic goes that over 5000 should be hardwired and thus power switched? Possible. But there are >8kW generators and they come with a 30A to multi-15A splitter (which is not an isolator). Maybe loosey goosey written and/or outdated... | |
| Jan 12, 2023 at 19:13 | comment | added | Chris Knudsen | "what does that have to do with power rating (over/under 5000W)" 5000W/240V = 20A, resulting in 12AWG (North America) wire. Finding extension cords larger than that, though possible, is uncommon. Power levels like this are better hardwired with a transfer switch, in my fully un-qualified opinion. | |
| Jan 12, 2023 at 19:11 | history | edited | P2000 | CC BY-SA 4.0 |
added 24 characters in body
|
| Jan 12, 2023 at 19:10 | comment | added | P2000 | @BenVoigt correct. And so what does that have to do with power rating (over/under 5000W) ? There are portable generators over 8000, and someone could wire in a generator under 5000W and cause lots of trouble. | |
| Jan 12, 2023 at 19:09 | answer | added | Peter Bennett | timeline score: 2 | |
| Jan 12, 2023 at 19:08 | history | edited | P2000 | CC BY-SA 4.0 |
added 84 characters in body
|
| Jan 12, 2023 at 18:57 | comment | added | Ben Voigt | I think the "portable generators" they speak of, used without a transfer switch, involve you unplugging some appliances from your wall receptacles and plugging them into the generator (via extension cord) instead. Power from the generator never enters your house wiring, so no transfer switch is needed. | |
| Jan 12, 2023 at 18:53 | history | asked | P2000 | CC BY-SA 4.0 |