Correct Voltage - SailNet Community
 
LinkBack Thread Tools
post #1 of 1 Old 01-03-2002 Thread Starter
Contributing Authors
 
Join Date: Jan 2000
Posts: 266
Thanks: 0
Thanked 10 Times in 7 Posts
Rep Power: 16
 
Correct Voltage

I have a generator that is putting out 133 volts. I am concerned that this is too high and may damage items on my boat over the long term. Is there a range that is considered acceptable for being over and under voltage?

Tom Wood responds:
Small diesel and gasoline-powered motor generators have a bad reputation for putting out "dirty" power—alternating current that has an uneven cycle, undulating voltage, or irregular amperage. In fact, some of them are so bad that a standard analog voltage meter is incapable of reading the line voltage correctly. So you should probably begin by confirming the generator’s 133-volt reading with an RMS voltmeter.

An RMS (Root Mean Square) meter is the only correct way to measure voltage accurately (and the only way to measure the square-wave output of most inverters at all). Since they are expensive, most boat owners don’t want to invest in one just to take an occasional measurement. But every professional electrician has one—the company best known for making RMS meters is Fluke, and many electricians call them Fluke meters. I suggest you beg, borrow, or barter the use of a RMS meter and double-check your voltage output before going any further.

The standard for AC appliances running on over or under-voltage is 10 percent. So a 120-volt appliance would have a running range of between 108 and 132 volts—one volt shy of your measured 133 volts. But the problem is more complex than that. If you start picking up your appliances and reading the tags on them, you will soon see that some were designed to run on 110 volts, a few on 115 volts, and the rest on 120 volts. A motor designed and built to run on 110-volts would operate comfortably on voltages from 99 to 121, but 133 volts would be far too great. You can see that any appliance, whether it was built for 110, 115, or 120 volts would run well on any of the three line voltages and still be within the 10 percent parameters.

If a measurement with an RMS meter confirms that your generator is indeed putting out 133 volts, it’s time to either adjust or replace the voltage regulator. The indication is that the generator itself is fine, but the setting on the regulator is allowing the voltage to drift too high. Best of luck to you.

Tom Wood is offline  
Closed Thread

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

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

 
For the best viewing experience please update your browser to Google Chrome