Onan 2.8k Generator Voltages

[peteco]

I checked the voltages while exercising the generator today.

Minimal load: 127v
~1200w: 116v
~2500w: 108v

I searched but couldn't find any information. Are these the expected voltages?

[hbn7hj]

I thinks so. I haven't seen 108 volts with the A/C on, mine is higher, but the no load number is about the same. These numbers are adjustable, to some extent, with adjustment of the mechanical governor per the manual. You will need a frequency counter and AC voltmeter.

[rowiebowie]

Originally Posted by peteco

I checked the voltages while exercising the generator today.

Minimal load: 127v
~1200w: 116v
~2500w: 108v

I searched but couldn't find any information. Are these the expected voltages?

I recently had a similar generator problem with my '2012 QG 2800KV. It started and ran good, powered my 15K A/C with seemingly no problem, yet all was not as good as it seemed. Power output was similarly low (slightly lower than yours, actually) and bad for my A/C.

Using my Progressive Industries EMS-PT30X plugged into the galley outlet through an adapter, I found the low generator output. I was getting 117 volts at rest, but only 57 Hz. Output dropped to 106 volts/ 53 Hz under a load of 12-13 amps.

I posted a request for technical help to fix my Onan Generator's low power output on airforums ast http://www.airforums.com/forums/f448...qg-186103.html.

After I made the successful adjustments, and my problem was solved. The Service Manual on my Onan gas 2800 KV says no-load max is 130v/63Hz; while under load it should be 120v/59.5Hz minimum. I'm now getting the proper Hz under both conditions, but slightly less voltage (-3 to 4 volts) whether under load or at rest, but I should be good.

Until your post, I've never seen another post on generator output. Sure, there are many posts on running issues, inability to start A/C's, noisy operation, etc.

It is possible low-voltage is an overlooked potential problem for many others. How many more generators out there get serviced and never adjusted to proper output levels? Probably more than we think and worth testing, in my opinion.

[peteco]

Originally Posted by rowiebowie

I recently had a similar generator problem with my '2012 QG 2800KV. It started and ran good, powered my 15K A/C with seemingly no problem, yet all was not as good as it seemed. Power output was similarly low (slightly lower than yours, actually) and bad for my A/C.

Using my Progressive Industries EMS-PT30X plugged into the galley outlet through an adapter, I found the low generator output. I was getting 117 volts at rest, but only 57 Hz. Output dropped to 106 volts/ 53 Hz under a load of 12-13 amps.

I posted a request for technical help to fix my Onan Generator's low power output on airforums ast How do you set RPMs on Onan 2800QG - Airstream Forums.

After I made the successful adjustments, and my problem was solved. The Service Manual on my Onan gas 2800 KV says no-load max is 130v/63Hz; while under load it should be 120v/59.5Hz minimum. I'm now getting the proper Hz under both conditions, but slightly less voltage (-3 to 4 volts) whether under load or at rest, but I should be good.

Until your post, I've never seen another post on generator output. Sure, there are many posts on running issues, inability to start A/C's, noisy operation, etc.

It is possible low-voltage is an overlooked potential problem for many others. How many more generators out there get serviced and never adjusted to proper output levels? Probably more than we think and worth testing, in my opinion.

Great info. I need to check that out when I have time. Have you loaded yours to 20+ amps?

[rowiebowie]

The biggest load I've put on it is the new 15K btu A/C. The running amps on high fan are showing 13-14A on the display with brief spikes over 20 during compressor startup. It may read a few amps higher with the charger working, but even then, 17 amps is the most load I've put on it since I can't run the microwave or water heater simultaneously.