Posted by MarkB_MI on September 21, 2022 at 23:24:57 from (174.240.147.69):
In Reply to: Amps vs watts. posted by DeltaRed on September 21, 2022 at 19:08:24:
For purely resistive loads, you divide the watts by the voltage. HOWEVER, you need to understand that the rated power (watts) ASSUMES a nominal voltage, typically 120 volts. If your voltage is higher or lower, the actual current will be higher or lower, respectively, than this calculated value.
Here's an example: A 1200 watt resistive device, rated at 120V, will draw 10 amps at its rated voltage. But what if your house voltage is 125 volts? The actual current draw will be 10.4 amps. (Ohm's law tells us the load resistance is 120 volts ÷ 10 amps = 12 ohms; at 125 volts the current is 125 ÷ 12 ohms = 10.4 amps.) Probably close enough for your purposes.
BUT, when you start dealing with inductive loads, particularly motors, it's a whole 'nother ball game. First, although motors are often rated by power (either in horsepower or watts), they draw VOLT-AMPS, aka apparent power. Without going too deep, just understand that a AC motor's volt-amps will be significantly higher than its power. For example, a 1200 watt motor might actually draw around 1700 volt-amps.
The other thing about motors is they tend to draw however many amps they need. This means that as their supplied voltage drops, they tend to draw MORE AMPS, unlike resistive loads which behave in the opposite way. That's why a motor that works just fine plugged into the wall will blow the circuit breaker when you put it on an extension cord.
I'm going to assume the appliances you're dealing with are purely resistive, but if they're not tell us what you have and we'll go from there.
Upload one or more videos to your post. Photo and video filesizes should be less than 5MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Talk of the Town: How to Remove a Broken Bolt - by Staff. Another neat discussion from the Tractor Talk Discussion Forum. The discussion started out with the following post: "I have an aluminum steering gear housing with a bolt broken off in it. The bolt is about a 3/8" x 1 1/2" bolt. I've already drilled the center of the bolt out with about 7/64" drill bit the entire length of the bolt. Only one end of the bolt is visible. I tried to use an easy out but it wasn't budging and I didn't want t
... [Read Article]
Latest Ad:
2022 John Deere 5045E, 4wd, front end loader and 3rd function with grapple. 120 hrs, 55k new, must sell
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
