Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-09-2016, 07:32   #1
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 16,490
Voltage Regulation on Capacitor Generators

I have a Nexgen 3.5 KW generator. I adjust RPM to achieve 60 cycles under load and that gives me a voltage of 110 VAC, let the gen slow down to 59 cycles and voltage drops to 107, 58 cycles under heavy load and voltage is down to 105.
Now ideally my AC appliances want to see 120 VAC, less than 120 VAC will I believe shorten the life of my electric motors like the air conditioner compressors and of course lower voltage means higher amperage.

Is there a way to increase voltage to close to 120 VAC? I am unaware of any adjustment except maybe turn the RPM up?
__________________

__________________
a64pilot is online now   Reply With Quote
Old 12-09-2016, 07:55   #2
Registered User
 
svHyLyte's Avatar

Join Date: Mar 2006
Location: Tampa Bay area, USA
Boat: Beneteau First 42
Posts: 3,379
Images: 25
Re: Voltage Regulation on Capacitor Generators

Quote:
Originally Posted by a64pilot View Post
I have a Nexgen 3.5 KW generator. I adjust RPM to achieve 60 cycles under load and that gives me a voltage of 110 VAC, let the gen slow down to 59 cycles and voltage drops to 107, 58 cycles under heavy load and voltage is down to 105.
Now ideally my AC appliances want to see 120 VAC, less than 120 VAC will I believe shorten the life of my electric motors like the air conditioner compressors and of course lower voltage means higher amperage.

Is there a way to increase voltage to close to 120 VAC? I am unaware of any adjustment except maybe turn the RPM up?
Let me start by saying I am not a generator or diesel expert, however.... I wonder whether there is something amiss with your control module. We have a 4.2KW Panda that operates at a set RPM whether it's fully loaded or completely unloaded. There is a momentary slow-down when a new load comes on, such as the A/C kicking in but that lasts for only a second or less after which the generator powers up and resumes normal speed/operation at which point we have 120v. The only exception to this occurred when we had a problem with the capacitors caused by an improperly installed control module that had the capacitors aligned horizontally rather than vertically which allowed some of the oil to leak from the vent holes in the top of the capacitors. Then the machine would bog down a struggle while the voltage dropped precipitously. When I contacted the tech's at Panda and described the problem, the first question they asked was whether the control module was mounted properly--i.e. vertically. I discovered it was not--installed by an evidently illiterate electrician that couldn't read the installation instructions or make sense of the red arrow that pointed to a "This Side Up" placard. Correcting the issue and replacing the capacitors (not inexpensive) solved the problem.

FWIW...
__________________

__________________
"It is not so much for its beauty that the Sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."
svHyLyte is offline   Reply With Quote
Old 12-09-2016, 08:50   #3
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 16,490
Re: Voltage Regulation on Capacitor Generators

I know of only one capacitor, and no "Module"?
__________________
a64pilot is online now   Reply With Quote
Old 12-09-2016, 09:36   #4
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 16,490
Re: Voltage Regulation on Capacitor Generators

Seems I have come to find out that there is no separate voltage adjustment, if I want 120 VAC, I need to run her just over 60 Hz, I was told shoot for 63 Hz
__________________
a64pilot is online now   Reply With Quote
Old 12-09-2016, 10:14   #5
Registered User

Join Date: Feb 2009
Posts: 1,321
Re: Voltage Regulation on Capacitor Generators

If your unit is like the one below it is possible to raise the voltage by changing the capacitor. Can be tricky. The unit below is rated at 120V make sure that your’s voltmeter read accurately.

http://www.nextgenerationpower.com/I...rt/UCM1-35.pdf
Unless otherwise specified the UCM 1-3.5 is manufactured using a standard four wire capacitor regulated brush-less generator. Standard wiring is 120V 60 Hz output.
__________________
chala is offline   Reply With Quote
Old 12-09-2016, 10:57   #6
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 3,893
Re: Voltage Regulation on Capacitor Generators

Capacitor regulated generators often have difficulty maintaining the right voltage with loads that have lagging power factor. An air conditioner is one example of such a load.

To see if the load is causing a problem turn on an extra load like a water heater or toaster. If the voltage goes up with the additional load then the regulation issue is probably related to the lagging power factor.
__________________
transmitterdan is online now   Reply With Quote
Old 12-09-2016, 11:27   #7
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,386
Re: Voltage Regulation on Capacitor Generators

I raised the voltage on my capacitor controlled alternator by going from 31.5mf to 35mf. Raised it from ~114v to ~126v no load. There is about 10-12% variation between no load and full load.

Mine has (2) capacitors, but it's a 4 pole alternator running @ 1800rpm, whereas yours may be a 2 pole running @ 3600rpm.

I would think staying within 10% of the original capacitance would not hurt anything. Also, I have seen these capacitors 'age' and die slowly, hence the voltage will drop slowly over time and you may not notice.
__________________
DotDun is offline   Reply With Quote
Old 12-09-2016, 11:39   #8
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 16,490
Re: Voltage Regulation on Capacitor Generators

Quote:
Originally Posted by DotDun View Post
I raised the voltage on my capacitor controlled alternator by going from 31.5mf to 35mf. Raised it from ~114v to ~126v no load. There is about 10-12% variation between no load and full load.

Mine has (2) capacitors, but it's a 4 pole alternator running @ 1800rpm, whereas yours may be a 2 pole running @ 3600rpm.

I would think staying within 10% of the original capacitance would not hurt anything. Also, I have seen these capacitors 'age' and die slowly, hence the voltage will drop slowly over time and you may not notice.

I think this is likely it, about the only thing you can vary is the capacitor.
I think measuring a capacitor takes a special multimeter, I had one at one time, lord knows where it is. Maybe I'll get lucky and the value will be printed on the Cap.
__________________
a64pilot is online now   Reply With Quote
Old 17-09-2016, 12:29   #9
Registered User

Join Date: Feb 2009
Posts: 1,321
Re: Voltage Regulation on Capacitor Generators

Quote:
Originally Posted by a64pilot View Post
if I want 120 VAC, I need to run her just over 60 Hz, I was told shoot for 63 Hz
Yes, adjust the speed of the generator to be at 60 Hz when on load but do not exceed 63 Hz off load, more than that may damage the alternator (poles throwing).
__________________

__________________
chala is offline   Reply With Quote
Reply

Tags
generator

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Atomic 4 voltage regulation EveningTide Electrical: Batteries, Generators & Solar 2 08-03-2013 16:15
Zener Diode or Capacitor with mcck Onan Control-o-Matic Genset? sdowney717 Electrical: Batteries, Generators & Solar 0 22-11-2011 09:02
Need a new capacitor in Panama Meck Electrical: Batteries, Generators & Solar 4 19-03-2011 18:38
Split Capacitor on Windlass Motor Terminals - Why? Zul Anchoring & Mooring 2 16-11-2009 08:14
Generators - Have you Heard of Boliy Generators? KayW Electrical: Batteries, Generators & Solar 5 27-10-2009 02:57



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:32.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.