Your last generator Maintenance Run

[3930dave]

My son found out how occasionally running and running them dry helps when you really need them to run when you need it. Friday a.m. N. Florida had a storm that knocked down tree and took out power lines. His 3500/4800 watt gen is running his refrigerator and freezer and a fan and lights. He has a camper it will run so he can use the a/c.

For a Northerner, I can take some heat, but FL would be getting rough this time of year w/o A/C.

With today's food prices, IMO all a small gen has to do is get you through one outage, and lack of spoilage pretty much pays for it . Exercise is good, not just for people !

Hopefully the local utility is back up for them soon.

Rgds, D.

 

[JPRambo]

Just got a text message from him. Power came on at 7pm tonight. Approximately 36 hours. Not terrible.
He was living with us in 2004 in swflorida when hurricane Charlie come into town. We did not have power for 10 days.

 

[Chilliwack Murray]

It does seem likely it's 325KVA, which would bring it to about 260KW using a .8PF if I'm doing the math right?

The alternator is rated 325kW but the genset as a package is limited to the horsepower of the engine. Alternators only come in standard ratings, unlike a consumer unit that has the alternator built for the specific model.

You have a 250kW genset…

360hp x .746 = 268.56 kWm (mechanical)

268.56 kWm x 93% = 249.76 kWe

(typical efficiency on an alternator this size is usually 93 and change)

It’s also common to oversize an alternator to provide more amperage for motor starting. Since motor starting is typically a low power factor load it doesn’t take a lot of horsepower (kW), just a lot of copper to deliver those amps.

 

[Jims1025R]

I bought my Honda 5Kw used in 1988. I used it to build my house, before Hydro came in. I don't use it much these days (hydro came in, and works very reliably!), but I do look for reasons to run it. I drilled 3/4" holes through two big maple trees for the kids zip line last week. That Honda started second pull, and ran like a champ. I have changed oil over the years, but I think it's still the same spark plug!

 

[Robin Veerman]

I like my Hondas too. I also had a trusty Honda 5000 but several years ago sold it to buy an EM6500SX electric start. It’s quieter than the 5000 was and no worse on fuel. I exercise it regularly and always drain the carburetor afterwards, using the handy OEM drain. It’s my new pride and joy

 

[3930dave]

Just got a text message from him. Power came on at 7pm tonight. Approximately 36 hours. Not terrible.
He was living with us in 2004 in swflorida when hurricane Charlie come into town. We did not have power for 10 days.

That was fairly quick.

Last really big wide-area event up here was the '98 Ice Storm, that hit your NE too. Some rural people were out for many weeks.

Rgds, D.

 

[3930dave]

The alternator is rated 325kW but the genset as a package is limited to the horsepower of the engine. Alternators only come in standard ratings, unlike a consumer unit that has the alternator built for the specific model.

You have a 250kW genset…

360hp x .746 = 268.56 kWm (mechanical)

268.56 kWm x 93% = 249.76 kWe

(typical efficiency on an alternator this size is usually 93 and change)

It’s also common to oversize an alternator to provide more amperage for motor starting. Since motor starting is typically a low power factor load it doesn’t take a lot of horsepower (kW), just a lot of copper to deliver those amps.

Thanks CM. Always appreciate the Engineering details, esp. on the big stuff most of us don't get near.

Rgds, D.

 

[3930dave]

I bought my Honda 5Kw used in 1988. I used it to build my house, before Hydro came in. I don't use it much these days (hydro came in, and works very reliably!), but I do look for reasons to run it. I drilled 3/4" holes through two big maple trees for the kids zip line last week. That Honda started second pull, and ran like a champ. I have changed oil over the years, but I think it's still the same spark plug!

Mobile projects are a great way to get exercise, for us and generators !

Even Hondas can have issues, with sitting too long.

Rgds, D.

 

[3930dave]

View attachment 869403I like my Hondas too. I also had a trusty Honda 5000 but several years ago sold it to buy an EM6500SX electric start. It’s quieter than the 5000 was and no worse on fuel. I exercise it regularly and always drain the carburetor afterwards, using the handy OEM drain. It’s my new pride and joy

Like firetrucks, Hondas look good in Red !

Rgds, D.

 

[moriboy]

The alternator is rated 325kW but the genset as a package is limited to the horsepower of the engine. Alternators only come in standard ratings, unlike a consumer unit that has the alternator built for the specific model.

You have a 250kW genset…

360hp x .746 = 268.56 kWm (mechanical)

268.56 kWm x 93% = 249.76 kWe

(typical efficiency on an alternator this size is usually 93 and change)

It’s also common to oversize an alternator to provide more amperage for motor starting. Since motor starting is typically a low power factor load it doesn’t take a lot of horsepower (kW), just a lot of copper to deliver those amps.

Awesome, thank you for the info!

 

[90cummins]

I bought a specially optioned new L70 (3.7 kw) long run Yanmar and mated it to a 5kw gen head for that same reason, more surge capacity.
It doesn’t even flinch when starting the 2hp hydraulic lift pump on my loaded Mohawk 10k lb auto lift.
I have a 4kw Generac XL4000 that won’t start it unless I unload the pump & let it spool up.
Copper is King!
90cummins

 

[3930dave]

I bought a specially optioned new L70 (3.7 kw) long run Yanmar and mated it to a 5kw gen head for that same reason, more surge capacity.
It doesn’t even flinch when starting the 2hp hydraulic lift pump on my loaded Mohawk 10k lb auto lift.
I have a 4kw Generac XL4000 that won’t start it unless I unload the pump & let it spool up.
Copper is King!
90cummins

While I'll never argue w. More Copper, Respect for the Tq out of the little Yanmar Too !

Rgds, D.

 

[90cummins]

Agreed.
However my testing of two identical Generac XL4000 generators I found the problem to be a lack of generating potential not lack of HP or speed.
I say this because both Generac’s had identical voltage drop 105 volts with a load of 3.5kw’s. With a 4kw load voltage was less than 100 volts while the frequency stayed at 60 +- 2HZ.
The original literature rated it at 4kw with a surge capacity of 4.5kw.
In my experience any new or used generator should be properly tested to start & operate your actual loads.
DO NOT assume your new generator will operate as advertised in the literature.
The least you should do is have a volt meter to monitor the voltage on both legs if it is a 240 volt generator.
Sorry for the lecture but one thing leads to another and another.
There’s really no good spot to sign off when talking about generators and home connections.

90cummins over & out!

 

[3930dave]

Agreed.
However my testing of two identical Generac XL4000 generators I found the problem to be a lack of generating potential not lack of HP or speed.
I say this because both Generac’s had identical voltage drop 105 volts with a load of 3.5kw’s. With a 4kw load voltage was less than 100 volts while the frequency stayed at 60 +- 2HZ.
The original literature rated it at 4kw with a surge capacity of 4.5kw.
In my experience any new or used generator should be properly tested to start & operate your actual loads.
DO NOT assume your new generator will operate as advertised in the literature.
The least you should do is have a volt meter to monitor the voltage on both legs if it is a 240 volt generator.
Sorry for the lecture but one thing leads to another and another.
There’s really no good spot to sign off when talking about generators and home connections.

90cummins over & out!

Walking the Walk..... nothing beats actual real-world testing. Good advice, esp. for someone getting their first generator.

One State I haven't been to yet is Missouri.... but relative to the above ^, I might as well have been born there !

In some respects, incandescent bulbs still have value IMO. If no instrumentation is available (emergency etc.), having a known incandescent bulb plugged in may give you a hint that something is off with the voltage (vs. an LED one).

Rgds, D.

 

[Darth_DMack]

We just completed construction and final move in, on our new home. We have a chunk of land, and are pretty remote. I opted for a Generac 26kw genset, and a 1,000 gal propane tank (buried). I have a gas fireplace in the great room, gas on demand tankless water heater and a gas range.

The genset "exercises" each week, and is all controlled via my Generac ap. So far, the Genset has been awesome! We've had two power failures due to storms recently, the Genset never missed a beat.

I'm watching the maintenance schedule closely.

 

[90cummins]

Walking the Walk..... nothing beats actual real-world testing. Good advice, esp. for someone getting their first generator.

One State I haven't been to yet is Missouri.... but relative to the above ^, I might as well have been born there !

In some respects, incandescent bulbs still have value IMO. If no instrumentation is available (emergency etc.), having a known incandescent bulb plugged in may give you a hint that something is off with the voltage (vs. an LED one).

Rgds, D.

Funny you mention incandescent bulbs. The local utility replaced my light fixtures twice first with cfl’s then LED’s. I have a huge supply of cfl’s & incandescent bulbs just in case there’s an event.
I view them like an old pre-emissions non electronic diesel like my namesake 90cummins.
Nothing can hurt a tungsten filament that’s in storage.

90cummins

 

[Chilliwack Murray]

I've found and fixed a number of issues that were either missed or couldn't be identified by the regular service people over the years with incandescent bulbs and/or analog meters. Even a cheap analog meter will provide data that requires a much higher end digital meter to see, and as a bonus, they always display the RMS value. Many digital meters display something between RMS and peak voltage causing a lot of people to think they have much higher AC voltage than they do especially when the sine wave is not pure.

Even a scope is not really the answer as most won't give the good visual in the .5 - 10 Hz range that an incandescent bulb will and this is often the frequency of voltage instability - especially when connected to the grid or other gensets.

 

[3930dave]

We just completed construction and final move in, on our new home. We have a chunk of land, and are pretty remote. I opted for a Generac 26kw genset, and a 1,000 gal propane tank (buried). I have a gas fireplace in the great room, gas on demand tankless water heater and a gas range.

The genset "exercises" each week, and is all controlled via my Generac ap. So far, the Genset has been awesome! We've had two power failures due to storms recently, the Genset never missed a beat.

I'm watching the maintenance schedule closely.

Nice setup !

Welcome to the thread. People like grs and CM that hang out here have forgotten more about fixing/servicing gens, than many people ever figure out. Yours shouldn't need attention for a while, but keep this thread in mind (ex. grs has a very nice telemetry set up on his Generac, that you can find a few pages back if you are interested/haven't gone that route yet).

Rgds, D.

 

[3930dave]

Funny you mention incandescent bulbs. The local utility replaced my light fixtures twice first with cfl’s then LED’s. I have a huge supply of cfl’s & incandescent bulbs just in case there’s an event.
I view them like an old pre-emissions non electronic diesel like my namesake 90cummins.
Nothing can hurt a tungsten filament that’s in storage.

90cummins

Takes space, but I remember load-banking industrial chargers with large 12v bulbs, many years ago

Rgds, D.

 

[3930dave]

I've found and fixed a number of issues that were either missed or couldn't be identified by the regular service people over the years with incandescent bulbs and/or analog meters. Even a cheap analog meter will provide data that requires a much higher end digital meter to see, and as a bonus, they always display the RMS value. Many digital meters display something between RMS and peak voltage causing a lot of people to think they have much higher AC voltage than they do especially when the sine wave is not pure.

Even a scope is not really the answer as most won't give the good visual in the .5 - 10 Hz range that an incandescent bulb will and this is often the frequency of voltage instability - especially when connected to the grid or other gensets.

Great examples CM.

I'll often take the time, with inexperienced people who are willing to learn, to recommend getting an inexpensive Incandescent bulb 12v test-light, to diagnose basic vehicle wiring.

Connected, but high resistance connection.... cheap incandescent will give you an indication, when often an LED may not....

Like Thoreau said..... often value in Simplifying.....

Rgds, D.