on October 18, 2007
I currently own two Kill-a-Watt P4460 meters. This usage meter has a memory hold over, so I can use these at circuits that are switched on and off. When the incoming electricity is shut off, the previous hours of use are kept in memory. When the electricity is turned back on, the meter will continue from where it left off. The older P4400 model does not have this hold over circuit. The P4460 is a great addition to the P4400 for studying home electical usage.
on January 3, 2015
The unit worked fine when performing testing the power consumption of a device for a limited amount of time. However, I ran into a problem when was using the Kill A Watt to test or monitor the power used on a device for an extended period of time. The unit is rated at 1875 watts ( Max Current 15 Amp and Max Voltage if 125 VAC )
In my particular case the receptacle on the Kill A Watt began to melt and turn brown when attached to a device that draws about 1,311 watts (117 Volts at 11.5 Amps ) which is below the maximum ratings of the Kill O Watt.
I really like these power meters, but some of them are not very accurate. I have tried 3 P4460s and several of the cheaper models and found that one of the P4460s read 86 watts when it should have been 80. That's off by 7.5%* and is way out of spec according to the manual (which says it is suppose to have .5% to 2% accuracy). I am returning that unit (the replacement I bought reads 83 watts which is better). Some of the other units were off too, but not by as much. Otherwise this is a nice unit but could include an optional short power cable which makes it much easier to handle and use. I like the fact that this unit does not lose readings when power is lost.
on January 13, 2008
Please read this entire review. There is an eye-opening surprise to the use of the P4460.
My office has been experiencing frequent partial power outages. Although we have a couple of uninterruptible power supplies (UPS) that are supposed to power the servers, telephone system, and a couple of administrative work stations in the case of power outages, we are finding that the battery back up supplies are simply shutting down without providing any power whatsoever to the hardware. We soon realized what was happening was that we had each UPS unit completely overloaded with too much equipment, so when the UPS battery was supposed to kick in, the UPS units would simply shut off completely, and we would lose all power.
Accordingly, I ordered the P4460 to take power readings of each piece of hardware so I could evenly distribute the power requirements over three different UPS units, thereby not resulting in overloading any one UPS.
Although each piece of equipment had a power consumption rating on its label, what I discovered with the P4460 completely shocked me. When each piece of equipment is powered up, there is a VERY sharp spike in power consumption, and the hardware's use of electricity reduces when the unit is up and running. For example, the phone system's video monitor power use was rated at 6 Volt Amps (VA), but when it powered up, it spiked to 85 VA. Likewise with Amps. Idle power was rated at 3 Amps, but spiked all the way to 68 Amps on startup. I found this to be the case with every piece of equipment. One server's idle power rating was 0.97 Amps and 90 VA, but on startup it jacked up to 1.92 Amps and 247 VA.
If I had only used each piece of equipment's listed power consumption on its label, I never would have known about the power spikes on startup, which, when combined, will absolutely overload a UPS, even though the combined idle power consumption falls within the UPS battery backup tolerances.
The P4460 is a terrific little unit and can even be used for extended periods of time for accurate power readings on equipment that cycles on and off, such as refrigerator compressors.
It's a bit more expensive than its smaller cousin, but worth every penny. Provides several types of readings and comes with very detailed instructions on how to use it so even a complete novice who knows nothing of electricity can benefit from its use.
I give this little unit a solid 5 stars.
on July 13, 2008
I have owned the original Kill a Watt for several years and find it to be a wonderful device with a few exceptions, however, the new updated unit is terrible.
The first and most important problem is that the display is not viewable unless you get down on the floor and use a flashlight. LCD displays have angles for best viewing and this one as most others are usually below the horizon of the display - so best contrast and readability occurs if you are looking up at the display from beneath it. In addition the mask for the display cuts off the top and prevents readings from any normal position.
Secondly the enunciators (labels that tell you if it is volts or amps) are tiny - so you not only need to get down on the floor with a flashlight but you need reading glasses as well to know which parameter the numerals represent.
I am fully cognisant of the fact that there is a memory and you can pull the item out of it's receptacle for a more convenient and better lit area. But where do you find one of those - no one places recepticles over head or at eye level that I know of - they are all about 1 foot off the floor. In addition the instantaneous reading of current (= not the electrical term) watts, or current volts, or amps is not memorized and pulling the device out of its working recepticle obliterates any instantaneous factor readings taken when you were measuring the device.
There are certainly many better ways to do the display - for instance locating the display on the top of the unit facing up. In addition a backlight could be added. And the parameters could be larger and clearer. In that way all you would have to do is bend down to find out your information.
I also find the menu system and toggling a big nuisance. The older unit was much easier to use. Each button had its own function. The readings were clear and straight forward - what you pushed was what you got. Now the menu and toggling system is obtuse, and time consuming. In addition in my unit the press switches did not work correctly - with sometimes nothing happening and other times it would jump three pushes with just one touch.
A last criticism is that the display should stay on when the unit is out of the wall. A small watch battery should be able to provide years of a nice contrasty display.
To sum thing up - I am very dissatisfied with its viewability and readability. It is very inconvenient to use. I am also dissastified with the logistics of the menu system - as it is haphazard and very poorly thought out. And I am dissastisfied with the control buttons which are intermittent and jumpy.
I will be returning my unit.
on January 6, 2008
I actually bought 2 of these, one was a gift. It works exactly as advertised so that is a plus right off the bat. I bought the EZ model which will make the Kilowatt hour/cost calculation for you; the less expensive model gives you the watt usage only and you have to do the math. For the EZ model you just put in the price per Kwh from your electric bill and it figures out the rest. I would recommend getting (2) 3-pronged extension cords, one to go from the plug on the back of the Kilowatt EZ into the wall socket and one to go from the appliance cord your testing into the front of the Kilowatt. This will eliminate having to get down onto the floor to read the thing. For instance my refrigerator plug is on the floor behind the fridge, not too convenient. If I didn't have an extension cord I would have to move the fridge all the way out and use a flashlight to read the screen. But once you overcome this rather obvious design limitation the product is a lot of fun to use. I was always concerned at how much my Christmas lights must be costing me so I tested it out. My big tree which has something like 700 lights costs $0.03/hr. Less than I expected. My outdoor lights cost about $0.10/hr. Not too bad either. My (2) tivo's use as much juice as my refrigerator which was a bit of a mind blower. Using this thing has made me more energy aware and I find myself shutting off things that aren't being used. I put power strips on certain "phantom" devices that suck power even when off like my TV and Stereo and DVD player. Get one, you'll see for yourself.
on January 8, 2008
This power monitor is really great. I bought a few of them and gave the others as gifts. I think it's worth the extra money for this model to be able to enter your cost from your electric bill and have the unit read out the cost per hour, day, week, month or year! One review complained about it being hard to read when plugged into the wall. Just use it with a short extension cord if the outlet for your refrigerator is behind it. Make sure the extension cord is the proper gauge, 14 gauge for a 15 amp circuit. This thing is so easy to use, you may not even need to read the directions! When you have collected enough data to get the proper accuracy, you can unplug it from the product and plug it in somewhere else to read the data. It doesn't loose the data, just read it out right away so it doesn't count any no energy use time and average it in with your previously collected data. When you are done and reset the unit to start monitoring another product, it clears the data but leaves the cost per kilowatt hour that you entered from you utility bill.
on June 27, 2008
I wont waste time by repeating what others in this forum have said about this tool, and just still with my own personal likes and nits about it.
* Easy to use, fairly fast readout.
MINOR NITS: (in no particular order)
* I wish it had the ability to report on the average, min and max readings, for things like bed warmers, trickle chargers and coffee maker warming plates (these items pulse on and off to maintain a set temperature or keep a capacitor/battery topped off) ... because the meter cant average, it's readout flops back and forth between negligable and significant, depending on when you look at it. It'd be nice if you could punch up a usage chart, with an adjustable scale.
* Lacks angled display or angleable/rotatable plug - as a result, in order to avoid getting on your hands and knees, or hogging the entire outlet, I recommend getting a 3ft grounded extension cord (not included) in order to comfortablly use this device (i.e., plug the extension into the wall, then plug the kill-a-watt into the cord, then the device you're analyzing into the kill-a-watt).
* Lacks lighted display.
* I wish this unit were capable of reading and processing usage of under 1 watt.
Bottom line: recommended.
That said, for those who are idly curious, here are some of the initial results of my own 'standby power use' survey of my house. It's not complete or exhaustive ... just some initial results, in no particular order.
Stuff taking no power or <1 watt while 'off':
* foodsaver, cuisinart food processor, kitchenaid standmixer, stick blender, braun coffee maker (it's tiny display is LCD, which takes negligable), bluetooth charger (which takes <1w even when actively charging, because the target battery is tiny), cell phone charger (0w not in use, 4w in use)
* Old black & decker toaster oven, sucking 4W ... which surprised me as it was a manually operated unit that has no visible lights (when off) or touch screens.
* My newer Sony DVD player had a standby power use of <1 watt, but an older Mitsubishi VCR player was sucking 4W, and was rarely being used. Yanked.
* My cablevision converter box (currently plugged into an uninterruptible power supply) uses 18w in standby, but I cant unplug it, or it needs to go through a multi-minute reboot. Gee, you'd think they'd equip the things with non-volatile memory. Anyway, I carefully plugged it back into my apartment's electrical carotid artery, and let it resume sucking power contentedly.
* Digital blood pressure monitor, sucking 3W, even when off and unlit. Yanked.
* Middle-aged Microwave ... 4W to run an unneeded clock (which is forever needing to be reset when the power blinks) and touch screen. Unfortunately, that gets used enough to stay plugged in as well.
Haven't had a chance to measure the fridge, TV or A/Cs yet ... meanwhile, Congress should pass a law requiring all household plug-in electrical devices to not just list their standby, average and max power use in the manual, but also on the exterior of the box. Also, I think virtually all household electronic devices should include a hard 'off' button.
Anyway, once I'm done with this, I'll loan it to my friends and family, because it hasn't reached it's break-even point yet.