Any ideas why high voltage on Powertech generator?

[belfert]

My electrician friend decided yesterday would be a good day to convert my Powertech generator to 120 volt only.  The issue is now it is running 135 volts on each leg.  We first thought that putting a load on it would lower the voltage, but my air conditioner wouldn't even start on the high voltage.

Any ideas?  I will call Powertech in the morning.

[Nick Badame Refrig/ACC]

Hi Brian,

135v will start your compressor but will also burn the windings in it.

I would have your electrition check the hertz.. Generators are set by Hertz, "60" is key.

Good Luck
Nick-

[JackConrad]

Brian,
   Are you sure he wired it correctly.  According to my PowerTech manual, Generator leads U-1 and U-2 are connected to ground (generator chassis, which should be grounded to bus chassis).  Generator leads V-1 and V2 are connected to the input side of the circuit breakers with a jumper added between the circuit breaker input terminals. 
   If you have the M Series Exciter Type, Generator leads T2 and T4 are connected to ground (generator chassis, which should be grounded to bus frame).  Generator leads T1 and T3 are connected to the input terminals on the circuit breakers with a jumper added beteen the circuit breaker input terminals
   Another possibility is that voltage regulator is not working properly.  I can try to scan and email you the schematics that you need them.  Jack

[belfert]

Thanks for the offer Jack, but I have the schematics.  That is what my friend used to make the changes.  I'll call Powertech tomorrow.

My unit has the T designations.  My electrician friend thought that putting a load on the unit might lower the voltage.  I hope the A/C unit isn't fried.  That would be an expensive mistake.

[JohnEd]

Belfert,

There may be exceptions to this but I doubt it:  no generator voltage drops into the accepted range only "if" you load it.  They all drop some when loaded but they stay in the acceptable range.  If the cycles or voltage are off don't connect anything and send for help.

Your friend isn't an electrician...he is a cross dressing shoemaker.

on the bright side I'll bet the generator is an easy and cheap fix.   Now the AC unit, that might cost more.

Good luck with this,

John

[belfert]

I haven't tried the A/C unit again since the high voltage incident.  I was smart enough to turn off the main breaker before starting the generator just in case something like this happened.  I should have used my better judgement and not turned on the breaker when the voltage was so high.

My friend is a really good electrician.  He has worked on lots and lots of big projects.  The only reason he had to quit a few years back is a undiagnosed case of Lymes disease that caused him to become disabled.

I suspect there is an extra connection somewhere in the generator that isn't hooked up that will fix the high voltage.  I sure hope I don't need to shell out $550 for a new A/C unit.

[Sojourner]

belfert....before you plug anything to it...do your self a favor. Plug in a 110 v ac dial clock or analog into generator that side by side to your cell phone's seconds or better yet another analog clock plug into land line power source. If generator is running too fast...it will cause the "generator clock" to run faster than land line power clock and will result a higher voltage.
Adjust your generator engine governor to slower or faster RPM until both analog clocks second hand is running the same speed or time matches. You should be in the 120 volt range after the adjustment.
All ac analog clock speed is depending by the cycle per second. Which is USA standard of 60 cycle.

Sojourn for Christ, Gerald

[JohnEd]

We are "hoping" right there with you.

Sorry if I offended you friend. 

Used AC units are a good deal.


Good luck,

John

[Lin]

Jerry may have a point.  I once had a Generac generator in which cycle and voltage were set by engine rpm.  I don't know if other generators are similar, but it's worth finding out>

[Busted Knuckle]

Jerry is probably on the $ on this! I don't know diddly about generators or inverters. But I have heard of a friend who had the same problem in a S & S and the engine speed was the culprit!

By the way I couldn't help noticing something odd! Somebody of great wisdom  & many posts has a "newbie" status. Must be a glitch in the board!   BK 

[Dreamscape]

Welcome back Jerry,

We've missed your expertise!

Paul

belfert....before you plug anything to it…do your self a favor. Plug in a 110 v ac dial clock or analog into generator that side by side to your cell phone’s seconds or better yet another analog clock plug into land line power source. If generator is running too fast…it will cause the “generator clock” to run faster than land line power clock and will result a higher voltage.
Adjust your generator engine governor to slower or faster RPM until both analog clocks second hand is running the same speed or time matches. You should be in the 120 volt range after the adjustment.
All ac analog clock speed is depending by the cycle per second. Which is USA standard of 60 cycle.

Sojourn for Christ, Gerald

[JackConrad]

By the way I couldn't help noticing something odd! Somebody of great wisdom  & many posts has a "newbie" status. Must be a glitch in the board!   BK 

Jerry decided to "start over".  Glad to have him back, really missed his expertise.  Jack

[belfert]

I talked to Powertech and they said to make sure a jumper wire was added.  If voltage still high than adjust the regulator via a screw.  What voltage should I be aiming for?  My house is about 124 volts.

[JackConrad]

This is a WAG, but I would say about 124-126 since you will get a couple volts drop when a load is applied. That is where our PowerTech seems to be when running with no load (factory setting).  Jack

[Sojourner]

Thank you all for the very nice comments.

Belford...good that you call Powertech.  I too would have done that to bring out any unknown information about the problem. After all it has more than one transistor, one resistor and one capacitor and what ever else it could be....right?

If your Powertech is variable RPM according to the power demand (I don't know if it available)...than the 60 cycle is fixed (build-in). Like the Onan RV Quiet Diesel generator is variable RPM with no change to the 60 cycle.

However, do check for the 60 cycle under load to be in design 60 cycle standard so your appliance will live longer and work properly every time and old "check" clock will be on time. 

All given setting RPM generator manufactures voltage will or can be varying at no load setting but make sure 60 cycles is to be within the 110-120 volt range.

In other words, you can over heat refrigerator's compressor or any non-brushes AC (alternating current) motor design to run on 60 cycles per seconds.

The bottom-line is be at 60 cycle in 115-120 volt to minimize ac motor overheating or burn out and at the same time wasting generator's fuel.

FWIW

Sojourn for Christ, Gerald