MEP-003 runtime with 100%+ loads

[Crawdaddy]

I know there has been talk in numerous threads about runtime in various amounts of overloading of the MEP-002/003 generators, but after some searches using the site's search and google with the site:steelsoldiers.com string, I can't seem to find it. I used keywords like mep-003, overload, runtime, trip, etc. and I found this thread (http://www.steelsoldiers.com/showthread.php?61257-MEP-002A-and-003A-main-breaker) about adjusting the breaker for earlier or later trips, but nothing saying the MEP-003 was spec'd and will run at 110% for x number of hours without issue. I think Issac or Sewerzuk have had this information in the past.

I recently got to do a load test on my 003 and was able to load it all the way up to pegging the meter at 133% for several minutes with my house load where it held without issue until the generator main breaker tripped a few minutes later. My "average" load for the house was somewhere between 100-115% indicated on the meter with it dropping down to 25% or so when the a/c units kicked off. So in the end, my question is how long can I load the generator at what is my average load of 115% without cause for concern. I am aware that the 10kw rating is based on a .8 PF rating which is technically 80% on the meter. The generator is used for household backup during hurricanes.

 

[Isaac-1]

I personally would not be too concerned about running a MEP-003a at 115% rated load during occasional outages, I might feel differently if it were being used for prime power at a remote camp, etc. Part of the post rebuild testing requires that these units handle a sustained load of either 110% or 115% for I think 30 minutes or an hour, I have also read somewhere in one of the specs that up to 110% load is allowed for 1 hour out of 10 or 12 in regular use. Also in our area after a hurricane you will likely be operating in an ambient temperature well below the rated operating range for the MEP-003a which will help its real world max output since it is based on temperature rise of the windings, etc. Now you say your average load is 115%, I have to ask how you measured this, and did you do it recently? Also how high is peak load?

Ike

 

[Crawdaddy]

The house has 4 window a/c units with a rating of around 15k BTUs each. I also had the water heater, washer, and the well pump running to try to simulate a maximum load. I ran the test this past weekend so ambient temps were in the mid 70s. The load percentages I listed were observed on the panel meter on the generator itself (the center gauge on the panel). I wanted to get an amps reading, but I wasn't able to scare up a clamp meter to measure it. I never did reach the "peak" load as the generator main breaker tripped before I could pull in any more loads, but at that point the gauge was already pegged out at 133%.I know it's certainly not good to run it constantly at 133% even if the breaker did hold out, but at 115%, I think it's more reasonable.

I don't think I'd say that the generator would stay at 115% once the house cooled down since the a/c units are the main hog of power, but assuming that 2 of the a/c units will most likely be running at any given time as the house warms back up, I'd say the load wouldn't drop below 50-75% very often either. Based on what you said, I think I'm fine with the way I'll be running. She'll be loaded down most of the time giving a maximum fuel economy, avoid wet stacking (which I know isn't really an issue with the 002/003), and keep me comfortable while the storms are bearing down on us. I just can't do a load of laundry while all the a/cs are on...