Generator kinda fixed - Replace regulator next?

belfert · October 06, 2019, 10:44:39 AM

Clifford recommended a new fuel filter as my generator might be starving for fuel. I replaced both the fuel and the air filters and now the voltage is much better, but still not great. I get about 127 volts at no load. I had three rooftop A/C units and a 1,500 watt heater running and it dropped to around 113 volts initially. After a bit I checked again and it was at 117 volts. (I verified the compressors were all still running.) I also checked at the generator and no difference.

A 10 volt drop seems high to me. Should I still replace the regulator, or do I need to have the Cat 3011C engine checked at the Cat dealer? It is better than it was.

Geoff · October 06, 2019, 01:19:07 PM

Quote from: belfert on October 06, 2019, 10:44:39 AM
Clifford recommended a new fuel filter as my generator might be starving for fuel. I replaced both the fuel and the air filters and now the voltage is much better, but still not great. I get about 127 volts at no load. I had three rooftop A/C units and a 1,500 watt heater running and it dropped to around 113 volts initially. After a bit I checked again and it was at 117 volts. (I verified the compressors were all still running.) I also checked at the generator and no difference.

A 10 volt drop seems high to me. Should I still replace the regulator, or do I need to have the Cat 3011C engine checked at the Cat dealer? It is better than it was.

Your readings sound good to me!

richard5933 · October 06, 2019, 01:27:39 PM

Similar readings to what I have with my Perkins/Kohler 12.5kw

DoubleEagle · October 06, 2019, 02:14:41 PM

Don't forget that the meter measuring the voltage might be off a bit, depending on its quality. Harbor Freight level, who knows; Fluke, probably dead-on accurate.

belfert · October 06, 2019, 03:18:12 PM

The meter is about a $40 Greenlee meter purchased probably a dozen years ago. Even if the actual numbers are a bit off I still don't like a 10 volt drop.

I had to replace the regulator previously because I was only getting about 56 volts. That time the regulator was definitely at fault. I set it to 127 volts at idle because it was dropping so bad. If I had set it to 120 volts it would drop way too low. I'll probably just send the new regulator back and live with what I have.

oldmansax · October 07, 2019, 03:35:15 AM

You have 3 things in play here. The first would be the engine itself. Checking the frequency with a good meter will rule out engine problems. Standard A/C in the US is 60 Hz. On a generator, that is controlled by the RPM of the engine. Most gennies are either 1800 or 3600. A lot of people will set the no load frequency at 61 Hz. It should drop no more than 2 Hz under full load. That would put you at 59 Hz. under full load.

The next component is the generator (including the regulator). A good quality generator will drop 2-7 volts under full load WHEN MEASURED AT THE GENERATOR.

The final component is the wiring. You can get a lot of voltage drop across the wiring, especially in a motor vehicle. If the first two checks read good, check the wiring for abraded or low capacity components.

TOM

belfert · October 07, 2019, 04:34:57 AM

I measured at the generator too and the difference between the generator and an interior outlet was less than one volt.

I don't think the meter I have can measure frequency good enough to try to check the frequency of the generator. I don't know how to change the governor settings if frequency is off.

Thanks everyone for your help. I have a number of things to check yet.

buswarrior · October 07, 2019, 05:47:31 AM

Get a kil-o-watt from amazon.

Hz, amps, volts, killowatts used.

Every busnut should have one, or more of them.

Very useful measuring device.

https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

Happy coaching!
Buswarrior

belfert · October 07, 2019, 06:11:30 AM

I talked to Jeff at Powertech today and he thinks my 10 volt drop under a fairly heavy load is normal. I have made arrangements to return the regulator I bought for $350. The voltage issues turned out to be a combination of loose wiring and not changing the fuel and air filters in over 1,000 hours. (Oil has been changed every 250 hours or once a year.)

I am still planning to check the frequency and a few other things.

Oonrahnjay · October 09, 2019, 05:59:22 AM

Quote from: buswarrior on October 07, 2019, 05:47:31 AM
Get a kil-o-watt from amazon.

Hz, amps, volts, killowatts used.

Every busnut should have one, or more of them.

Very useful measuring device. ...

Yep, I use mine just about every day. When you have a total-carp Outback inverter, you have to.

Dave5Cs · October 09, 2019, 02:42:43 PM

We got this one which is similar to the BW put up but it also has a menue, ad you can put in what you pay for your electric and see what each device is costing you. You set the rate, hours you want it to monitor etc. I find the onlyproblem with all these devices is that so far none of them take a 220 plug like for the dryer or AC units.

https://www.amazon.com/P3-International-P4460-Electricity-Monitor/dp/B000RGF29Q/ref=pd_sbs_60_1/142-0085577-1944600?_encoding=UTF8&pd_rd_i=B000RGF29Q&pd_rd_r=e6e2ef22-00f7-4311-bfdb-61c0d93298e7&pd_rd_w=JeJrS&pd_rd_wg=WGMkN&pf_rd_p=d66372fe-68a6-48a3-90ec-41d7f64212be&pf_rd_r=NM6QDJ9K1Q5CHQBVZT8P&psc=1&refRID=NM6QDJ9K1Q5CHQBVZT8P

sledhead · October 09, 2019, 02:47:33 PM

I have 2 of these . one on each leg so I can keep track of how much power I am using . they work great

https://www.amazon.ca/gp/product/B014W3D1OC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

on amazon.com they are a lot cheaper

dave

DoubleEagle · October 09, 2019, 06:38:33 PM

Quote from: buswarrior on October 07, 2019, 05:47:31 AM
Get a kil-o-watt from amazon.

Hz, amps, volts, killowatts used.

Every busnut should have one, or more of them.

Very useful measuring device.

https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

Happy coaching!
Buswarrior

The reviews are not always good; there are complaints of meltdowns and failures even when used below the rated capacity. It might be handy for light loads, only.

belfert · October 10, 2019, 04:47:48 PM

Does a Kill-A-Watt help measure the big loads like the inverter battery charger or the rooftop A/C units? The amp gauges others mentioned would seem like a better option.

buswarrior · October 10, 2019, 05:17:21 PM

Kill-o-watt is for anything you plug in.

It is NOT for whole coach system measuring.

Inexpensive (around $20 online) way to measure how much power the things you want to put in the bus use, while they are still in the house.

Great for real world planning what your boondocking loads might be.

For instance, plug your house refrigerator into it for several days to get some real measurements of power used in your operation.

Sizing a battery bank and inverter is confidently approached when one really knows how much power devices use.

And it has a hz meter to check the generator.

Happy coaching!
Buswarrior