Acquired a Military surplus load bank

Howdy,
Essex Electro Engineers A427 Load Bank



It was made around 1970. 0-33kw coverage, single and 3 phase. 3kw, 6kw, 9kw, 12kw switches in any combo, and a 0-3kw variable turn knob. It really makes thing easier to keep a generator in shape.

The MEP-803A can really pull some power. It actually takes a lot to get up to 133%.

Nice!!!! I have been looking for one my self.

Wow for a '78 that looks pristine! Pretty darn cool...errr hot!

If I bought one I would just have to tell the wife "its my new shop heater".

Congrats! I would love to have one of those.

For a moment there I thought it was a local firm near us. Essex. Looks a very useful unit to have.

Very nice score.

Good catch! (Can I borrow it?)

Put her to the test and give us some 803 data like surge capsbilities

jimbo913 said:

Put her to the test and give us some 803 data like surge capsbilities

Click to expand...

Howdy,
I wasn't watching too closely while loading the MEP-802A. I loaded it up to 133% for 15 minutes, then 100% for 30 minutes, then 25% and then off, but, the MEP-803A was a different story.

I had the 12kw switch on, and the 3kw switch on, and turned the variable knob up maybe halfway to get it to 133%, and I still spun the knob all the way (suppose to be 0-3kw variable) and it really starting grunting and bellowing out some black working smoke, did that for maybe a minute. The needle was way past the 133%. I then backed it down to 133%, ran that for about 10 minutes, then lowered it to 100% for 30 minutes, then 25%, then cooling, then off. If the switches are true and correct, the clamp meter said I had 54.7 amps on each phase, loading it on 3 phase. The load bank switches would mean around 16-17kw loaded 3 phase.

Is it just me that would have liked to see film of it loaded up black smoking till it cleared!

3-phase is a different beast. I don't know if it's true for these generators, but a lot of commercial gensets will derate when used in single phase. IE, I have a 35kw 3-phase Onan that becomes a 23kw when reconnected for single phase.

I'm wondering if the mep-803a can handle significantly higher loading in 3-phase than it can in single phase.
I'm sure you want to play with your new toy more... Wanna go run it at 1-phase 120/240? I'd like to see the amp clamp numbers for that, see if it's output is much less than in 3 phase.

Howdy,
I guess I only recorded and short video of the MEP-802A being loaded. At the moment it looks to be around 133% load, and then I lowered it a little to 125%. By looking at the video, I would say the load is around 7.5-8kw 3 phase.

I have a 35kw 3-phase Onan that becomes a 23kw when reconnected for single phase.




Not sure on the connection, mine is an 002A, 52,26,17.3 amps in 120 single , 120/240 single and 120 208 three phase,

Howdy,
The MEP-803A data plate says


120v 1ph = 102
120/240v 1ph = 52
120/208 3ph = 34

The MEP-802A data plate says


120v 1ph = 52
120/240v 1ph = 26
120/208 3ph = 17

Man, I know they're "Quiet" next to an 002, but those things are still loud...

Ratch said:

Man, I know they're "Quiet" next to an 002, but those things are still loud...

Click to expand...

howdy,
I am thinking about taking the lifting rings off. They just sit there and rattle like bells. I saw where someone said to shoot a bunch of silicone there, but I think that would only last a short time. I have forks, so I do not need them. It really is amazing how smooth the 803 is compared to the 802. I know it's a 2-cylinder, but it shakes.

Did the Hz / volts drop significantly at 133%? I dont need that much power on a constant basis but it always runs through my mind, "what if" everything kicked on at the same time (fridge,freezer,well, water heater compressor,AC, etc) and I spike to 15-18Kw for 2 seconds (240v single phase).

jimbo913 said:

Did the Hz / volts drop significantly at 133%? I dont need that much power on a constant basis but it always runs through my mind, "what if" everything kicked on at the same time (fridge,freezer,well, water heater compressor,AC, etc) and I spike to 15-18Kw for 2 seconds (240v single phase).

Click to expand...

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Frequency will droop with sudden loads but should level out in a second or two. This droop can help start motors. The voltage should drop only for a fraction of a second. But this all depends on the type of motor.

brushed universal motors are really bad at causing voltage spikes due to their very high inrush current. Things like circular saws, drills and the like which are meant for short run times.

Howdy,
I ran the MEP-803A today on the load bank. The video is huge. Its 536mb, and about 4 and a half minutes long. I warm the 803 up. I then start stepping through loads.
3kw, then 6kw, then 9 kw, then 12kw, then 12kw+3kw, then I start adding the variable load a little more than half way. Probably adding another 1.75kw to get it up to 133%. I then back off and throw 12kw and add 9kw, starts bogging down some, I try a few more huge load combinations. You can see the control panel faces and see the percent rated current throughout the video. I then bring it back to around 135% and its pulling 67.2 amps per line (120/240 single phase)

I then stopped the video and starting backing down cooling things off.

MEP-803A
4.22 minutes long
stepped load bank
Load Bank switch settings available. any combination, and the variable knob (0-3kw)