roof ac question

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82 Honey 27

82 Honey 27

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Joined
Jul 17, 2010
Posts
43
Location
Doerun, Ga.
i am new to this rv stuff and have a question. should my roof air blow harder when it is plugged into 110 volts than when it is running on the generator? i have a 4k generator and nothing else was on.  thanks in advance, mike
 
No, the A/C doesn't know where it's power is coming from.  An exception would be if your generator was putting out low voltage.  Do you have an AC voltmeter to check that?
 
thanks Ned. i will try that tomorrow. i am afraid to run it because i was afraid it might damage the ac unit.
 
If the generator voltage is low, it could damage the A/C compressor.
 
Ned said:
If the generator voltage is low, it could damage the A/C compressor.
Click to expand...

i only ran it for less than 5 minutes. as soon as i noticed it i turned it off. thanks,yall are the greatest!! :D
 
ok i checked the output of the generator and it was only 96 volts. i forced it to run faster and it went up to 106 volts. now i gotta figure out how to speed it up a little more. the lever on the carb butterfly is pegged out now!
 
Hoh Boy...be careful

  The first thing you should do is measure the RPM of the engine. The AC output must be close to 60 Hz.

If you simple adjust the speed higher you may be doing great harm to anything electronic hooked up.

You may have a voltage regulation problem as controlled by the circuit board in the generator.

Most generators of that size run at 3600 RPM at all times.

carson
 
thanks, what do i need to check the HZ of the output. i think i can find some kind of tachometer to check the rpms with.
 
82 Honey 27.  I can't begin to start an Electronics 101 course here.

  Since we don't know what your technical expertise is, I can only suggest a few things.

  I am assuming you have an Onan generator. Frequency measurement requires a piece of test-equipment. The easiest way would be to visit your local ONAN/Cummings dealer and have them check it out.

  What a lot of RV'rs use is a little device called a Kill-A-Watt voltage/power/frequency meter available on the web. for little money. It will tell you all you want to know about voltage and frequency and more.

  Measuring the actual RPM of the engine is another matter. I wouldn't get into that as that requires specialized equipment. 

  There are many sources (see link below). Some folks have said they found it a Homedepot. ?

Anyway, here is the link of a sample:  http://www.energyfederation.org/consumer/default.php/cPath/388_254?gclid=CIDMkIL30qMCFQXt7Qodblwftw

  Weigh your options but don't just crank up the engine to get the voltage.  Frequency takes priority.

Carson FL


 
actually i have a degree in electronic technology but it was in 1968!! ;) so i have a pretty good basic knowledge of this stuff. (what i have not forgot in 40+ years!! lol)  that little Kill-A-Watt thing looks pretty neat and is only 20 bucks. thanks,  mike
 
Yes they are assuming it is a conventional generator.  The number of poles in the generator determine the requirement for RPMs to generate 60 Hz.  I'm thinking that a 2 pole generator needs to turn at 3600 RPM and that a 4 pole needs to turn at 1800, but it has been a long time since I had AC Machinery in college as well.
 
ok i got my kill a watt meter. at the speed the gen. is running now, i am getting about 48-50 hz. i can speed up the engine a little and get 60 hz. with 117 volts. does this sound ok?  thanks, mike
 
Hi Mike.  The frequency is definitely too low.  You should read about 62 or so without load. With a full load you should read very close to 60 Hz.

  The adjustment is not with the throttle but rather with the governor adjustment.. The governor adjustment is very critical and sometimes hard to do.  The governor (a mechanical device) controls the throttle. One thing to remember, do not bend any springs nor lubricate any joints. Most governors have nylon joints and must be clean...not lubricated.

  I still suggest you seek some professional help in getting it back to normal.

Carson FL  98.2?



 
 
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