Generator Question

[Gene Blister]

For the electrically able out there...
I have an old chineesium generator I cleaned up, and it works great, but I want to use a 4-blade 30 amp cable wired to a thru-the-wall 6 plug outlet cluster. I’m confused by the note next to the panel outlet which reads 13A max. Is this a Chinese misprint? I thought this was a 30 amp connector which could run several 120v outlets.

 

[chim]

Check the nameplate data on the generator. What does that say. Markings on the outlet.

 

[GeoHorn]

I can only guess what you’re seeing...but as an example of misleading claims...HF has a “4,000 Watt” generator they sell as a loss-leader. It’s very popular. But the problem is.... it will not DELIVER 4K watts because the two outlets are served by 13A circuit breakers. 4K watts divided by 120 volts should equal 33.3 Amps.... but the outlets will not allow that many Amps to be pulled because of those 13A outlets. The most that can be continuously pulled is 3120 watts.... and presumably the max SURGE is 4K watts. Not only that but, for example, if you have a 15A airconditioner in your RV... you still can’t run it because of that 13A limitation of the individual outlet.

 

[BruceP]

Most generators are rated at CONTINUOUS and PEAK.

The PEAK may be 13Amps.... but the CONTINUOUS power draw might be significantly less. This is because the windings within the generator cannot dissipate the heat.

These two ratings are useful for understading if a generator can start a motor (HIGH CURRENT for a short burst,) like skillsaw or tablesaw. -vs- running electric heater which is a constant load.

 

[SidecarFlip]

I'm a little rusty but, isn't inrush amperage on a electric motor 3 times running amperage?

 

[85Hokie]

I'm a little rusty but, isn't inrush amperage on a electric motor 3 times running amperage?

Depends on what device is drawing the amperage - I have for S&G's used one of those WATT-O-METERS....and plugged in a 12" miter saw, you have to be quick, but those amps where in the 20's for a split second, after which it gets back down to 10-12 or so amps, bog it down and it will rise back up a bit too.

The thing that most people do NOT understand about breakers ..... it really is not the amps that make it trip, rather the heating up of the breaker BECAUSE of the flow of amps...... what I am trying to explain is a inrush of amps is so fast, it does not have time to heat the strip in the breaker. You need a constant load of amps to heat the strip just enough to trip it. As mentioned - you really need to look at the ol fine print to see what a genny can handle and what it will not handle in amp loading.

 

[skeets]

If I remember right the inrush for the first cycle can go to 1300%

 

[SidecarFlip]

If I remember right the inrush for the first cycle can go to 1300%

HuH????????????

 

[skeets]

Yep the spike can go to 1300% of the rated run amperage , that is usually for only like half or less of a cycle unless a motor goes into a locked rotor then all bets are off weather a breaker can clear fast enough

 

[lugbolt]

yup the chincanese will do that, marketing

they sell generators they don't care about what happens after it's sold

I sold and serviced generators for a long time and saw it daily. when we started carrying yamaha, we also carried the chincanese generators. If you took a 4KW yamaha and a 4KW Chincanese, an compared them, the yamaha won....every.single.time and not just in actual wattage.

the chincanese no-name stuff uses dirt cheap components that may or may not work as designed

and finally just because it has a NEMA 14-30 outlet on it doesn't mean it'll actually make 30A, which is the maximum current rating of a NEMA 14-30 outlet. You see this specification on a chincanese generator, but you see that "4 prong" and ASSuME that it's a 30A, it might only make 13 (if you're lucky) I used to sell them by the boat load when the snow was forecast, $400 generator with a RV outlet on it, and 75% of the people would gripe about them not making enough juice to run X appliance before kicking the breaker. So we had to actually start telling people that if they thought they needed, say, 5000w and they were looking at a 5000 or 5500w gen, we'd have to either advise them that it won't continuously run that, and/or get a bigger one to run the load you want it to run

I have a 3000 that "should" run a roof air, and it will if the air temp is below about 75 degrees (which at that point its senseless to run the a/c) , but when the air gets much warmer...like when I need a/c in the trailer? It won't start the compressor. Once it's started it'll run all day; or at least til it runs outta gas. Most of the time it won't start it though

 

[SidecarFlip]

I know my Champion 2000 watt inverter won't start my RV AC without the easy start kit which is a couple capacitors and some switching. I assume the easy start provides that split second inrush start amperage.

I have a 3000 that "should" run a roof air, and it will if the air temp is below about 75 degrees (which at that point its senseless to run the a/c) , but when the air gets much warmer...like when I need a/c in the trailer? It won't start the compressor. Once it's started it'll run all day; or at least til it runs outta gas. Most of the time it won't start it though

The easy start is nothing more that some cans that provide the extra start amperage, kind of like a static converter does for a 3phase motor running on single phase. Excites the 3 phase windings to get the motor past it's no revolution point up to enough rpm where inrush is no longer an issue. They do work well.

 

[GeoHorn]

I’ve got to jump in with a success-story here: In Dec ‘08 Pep Boys had a big SALE on stuff they probably shouldn’t have been carrying anyway....(They probably saw the recession coming and dumped stuff on the market...I wasn’t bright enough to see the train-wreck coming and spent money I should have been saving...the next month I was laid off... but. Anyway...)

...so Pep Boys had this 3500 watt generator on sale for $159 (normally $695) and I couldn’t resist. It is very small for it’s output, (weighs only about 75#...I can pick it up out of the truck-bed and handle it easily for a few yards to behind the nearest tree) with the “brand name” of “Coleman PowerMate” on it (But it’s clearly a Chonda).
It sat around here for two years with nothing to do as I had no real use for it...until the recession was over, I got my job back, and celebrated by buying a lightly-used Airstream with a roof AC.
Wife and I took a 3-month trip thru TX/NM/AZ/CO/WY/MT/ID the next year after I retired and it ran our AC, MicroWave, and everything else in that little RV (as long as we didn’t try to run the AC compressor simultaneously with the microwave...or wife’s hair-dryer... we’d switch the AC to blower-only while we heated up whatever for a few mins, then switch the AC back to “cool”.... was the only restriction. It’s lasted us for over 5 years now and puts a smile on my face every time we use that little cheapie. gotta admit, it’s not one of the “silent” inverter-types, but the only time we use it is “boon-docking” when we’re waaay out in the wilderness and no one around to bother. We can barely hear it inside anyway and it keeps bears out of the campsite.

 

[NHSleddog]

Before we went with a whole house setup, I bought a 6500W Honda. It was 3 times the cost of the "other" brands at the time. There is a reason they cost so much.

You can set a glass of water on this Honda when it is running full-tilt and not spill a drop. It really is superior engineering in a generator. The power is also very clean comparatively speaking.

Our 15K NG whole house unit is a dream. I am between two isolation switches on the grid and we get cut off several times a year. It ran 6 hours the other day for a blown line/transformer.

I put a gen-power LED on the side of my box so the neighbors can see when the power comes back on (most of them have portable units).