MEP-803A Spare Parts

[Guyfang]

I might have written many messages back, that you can learn a lot, by reading. And I know someone said something about one day, the light will come on, about army TM's. It will, if you give it a chance.

Zed is correct, as to why the starting amperage is high. There are several ways to correct this problem, if you just have to. There are many threads about "soft start" and other such things. I am sure someone will jump in here to help you get started. You are making headway.

 

[SalmonSlayer]

So as many of you have already figured out, I'm not exactly a wiz at electricity...but I'm learning. sorry in advance for the long winded question but here goes..

ive got the 803A running 120/240 single phase powering the main panel in my building. the only thing that's 240 is the walk in freezer, everything else is 120. now it may be true that i don't have everything balanced as well as it should be and i can adjust that later by moving a couple breakers around in the panel. so i understand that the 240 is achieved by two legs of 120 so when i am measuring at the lugs on the generator am i getting the amperage for each leg when i have the amp clamp on say the black wire then the red or am i getting total amperage of the unit. the way i see it if I'm getting 44 amps at the lug on the black wire and my gauge on the unit is showing 48% rated load then if its the total amperage my gauge should be showing roughly 84% instead however if i indeed need to consider that half of the total 104 amps possible on 120V then the gauge would be close to correct as that would be more like 42% total. even writing this I'm getting more confused, so if i misspoke anywhere please feel free to correct me

again sorry for long post and thanks in again for all the help you guys have already given me.

 

[SalmonSlayer]

I might have written many messages back, that you can learn a lot, by reading. And I know someone said something about one day, the light will come on, about army TM's. It will, if you give it a chance.

Zed is correct, as to why the starting amperage is high. There are several ways to correct this problem, if you just have to. There are many threads about "soft start" and other such things. I am sure someone will jump in here to help you get started. You are making headway.

not too concerned with needing soft start as the gen barely even burped when the freezer kicked on...just startled me a little when i had the clamp on set to INRUSH and couldn't figure out how the generator rated for 52 amps was able to read 84

 

[Daybreak]

Howdy,
Before you get to carried away... The freezer will have some vital information about its power requirements. Somewhere there will be a tag. The tag will tell all about the motor, the power it needs, and a LRA number.
maybe even saying motor 1hp, 208-240 LRA 80 running 30

A lot will also be told by the size the circuit breaker is for the freezer? dual pole 50 amp breaker? 40?, 30?

The meter on the unit might not be reading 100% correctly, that is why it is good to confirm with a separate meter. The MEP-803A is a 4 cylinder diesel set with a 12.5kw generator head. The military down rates the units. That is why it can run 100% load 24/7 without issue. The power factor for the gen head is .80 With that, to actually have 100% on the meter, you would need a 100% resistive load at 12.5kw. The MEP-803A gen head is a 10kw head, 12.5Kva PF .8
Look over my generator load bank thread with video and amps, and loading, and percent reading logs.
Acquired a Military surplus load bank

NOTE:
I see you have a 3 wire hook-up and a bare (I hope) ground wire. Or do I see a green wire too? You want only 1 ground point.

In the field = ground rod driven in the ground and wire attached to ground lug, bonding link in place.

If the place has regular power, and a servcie panel, meter etc... then you would use the ground in the service panel and you would have a 4 wire connection at the generator HOT L3, HOT L1, Neutral, and ground, bonding link removed.

Simple test - All items off, 1 1500 watt heater on one side of the panel, and 1 1500 watt heater on the other side of the panel, both on full, that equals a 3000w load. 3000 x .80 = the meter showing a 2,400 watt load on the meter so about 20% on the meter face.

 

[SalmonSlayer]

the bare ground is for the generator with a ground rod driven next to the unit. the green wire is from the panel. feel dumb asking but what's the bonding link?

 

[Daybreak]

Howdy,
The bonding link is the samll 3/4" by about 3 inches long flat bar connected there next to the nuetral lug.

You want only 1 ground location.

The Service panel which you are connected to, is it a fully installed service panel? and the ground neutral are bonded (the 2 are connected) in the service panel? That then is your ground point.

in the field = ground rod = wire to ground lug = bonding link in place

at a building which is wired = 4 wires connected to service panel = bonding link dis-connected.

 

[Zed254]

the bare ground is for the generator with a ground rod driven next to the unit. the green wire is from the panel. feel dumb asking but what's the bonding link?

1st pic is a 3 phase military wiring job. Lower right corner the ground to neutral bonding strap is in place. This generator is configured as an independent power source.

2nd pic is my wiring job, single phase. Lower right corner the ground to neutral bonding strap is open (has white tape on it). This generator is configured as my home back up. Because I have a ground to neutral bond at the house's breaker box I do not want a second ground to neutral bond at the backup generator. 2 ground to neutral bonds in a system can cause current flow that you do not want.

 

[SalmonSlayer]

ok i just checked a picture that i have and the strap is in place. maybe i should have clarified...the building is a salmon processing facility built in a 40' shipping container so it is completely portable. the generator is the only power source, my thought was that running the green from the panel to the generator and then the bare copper to the ground rod would ground both the genset and the facility at the same location thereby not needing two separate grounds

 

[Zed254]

I believe you are correct. However, if you ever get 'Alaska Electric Power' to your processing facility you would need to open the ground to neutral bond. As you describe.... your generator is the source of all electrical power, drop a ground rod (proper installation - check NEC... 8 or 10 feet I think), ground wires (correctly sized .... I think TM covers it), ground to neutral bond connected you should be good to go.

 

[SalmonSlayer]

... so i understand that the 240 is achieved by two legs of 120 so when i am measuring at the lugs on the generator am i getting the amperage for each leg when i have the amp clamp on say the black wire then the red or am i getting total amperage of the unit. the way i see it if I'm getting 44 amps at the lug on the black wire and my gauge on the unit is showing 48% rated load then if its the total amperage my gauge should be showing roughly 84% instead however if i indeed need to consider that half of the total 104 amps possible on 120V then the gauge would be close to correct as that would be more like 42% total.

so back to my original question...am i just reading the gauge wrong or measuring wrong...or is the gauge terribly out and i need to recalibrate


also this will be the only power source for the building. no power company near me

 

[Zed254]

Calibrate the gauge. Check connections on your percent amp gauge - confirm crimped fittings are tight and no corrosion. You have exercised the switches with contact cleaner so they should be good. Now calibrate the percent amp gauge and remember what everyone has said: these ain't particularly accurate gauges. Nice ball park reading to give the operator a feel for what's happening. Get 41.6 (the math made me put that decimal point there).....actually say 40 to 43....or so on your high amp leg. Make the percent amp gauge read 100%. At this point your machine will be derated to military standards and you can be pulling close to 100% and that fridge should still start...because you've got 20% back up dialed in. If you get to where you need more than 100% (42 amps +++) you need to start managing your electrical load.

I believe 240 volts Alternating Current is the combination of two legs of 120 volts directly out of phase by 180 degrees. Your fridge uses both legs of this AC current to run the motors & compressor. Your other services are all 120 so some can be moved to one or the other 120volt leg to balance the generator's load back at the lugs.

 

[Farmitall]

Calibrate the gauge. Check connections on your percent amp gauge - confirm crimped fittings are tight and no corrosion. You have exercised the switches with contact cleaner so they should be good. Now calibrate the percent amp gauge and remember what everyone has said: these ain't particularly accurate gauges. Nice ball park reading to give the operator a feel for what's happening. Get 41.6 (the math made me put that decimal point there).....actually say 40 to 43....or so on your high amp leg. Make the percent amp gauge read 100%. At this point your machine will be derated to military standards and you can be pulling close to 100% and that fridge should still start...because you've got 20% back up dialed in. If you get to where you need more than 100% (42 amps +++) you need to start managing your electrical load.

I believe 240 volts Alternating Current is the combination of two legs of 120 volts directly out of phase by 180 degrees. Your fridge uses both legs of this AC current to run the motors & compressor. Your other services are all 120 so some can be moved to one or the other 120volt leg to balance the generator's load back at the lugs.

That is correct, the neutral is not used only the two hots 180 out of phase, thats why you can load L1 and L3 output terminals with no other connections and operate a 240v device.

 

[DieselAddict]

For the full picture you need to take a current reading for each of the current producing legs (L1 and L3). If either of those legs gets to MAX amps then you are at 100% load. Any additional load must be added to the leg that is NOT at 100%. The issue is the load meter does not show this. It shows the total load of the supply and not the load per leg.

Since you are operating this unit as primary power and maybe not well balanced I suggest you install permanent amp meters on the both legs and using that info to know what your real load is. This can keep you from burning up the wires in the generator head.

 

[Daybreak]

Howdy,
OK, with some clarification.
a 40ft container, a MEP-803A as the only power source. Movable to area where it is needed. Then, that would be field style, only power source, drive a ground rod, connect to generator, bonding link in place, that will be your only grounding source. since you are using a regular service panel with breakers, does it have a main service breaker? In the service panel, do not bond ground and neutral, and have 4 wires running from generator to service panel and the power source (MEP-803A) is the grounding source. (to ground rod) I stated it this way because you have setup a complete breaker panel where you can bond neutral and ground.

Pictures of freezer tag
What size breaker is the freezer on?
what other power items will be used?

Balanced loads is nice, but, close enough will not hurt. Its when its way off say 45 amps one leg and 15 amps other leg, that could use more balancing. This is where the clamp meter helps. To see the draw on each leg.

 

[Farmitall]

Howdy,
OK, with some clarification.
a 40ft container, a MEP-803A as the only power source. Movable to area where it is needed. Then, that would be field style, only power source, drive a ground rod, connect to generator, bonding link in place, that will be your only grounding source. since you are using a regular service panel with breakers, does it have a main service breaker? In the service panel, do not bond ground and neutral, and have 4 wires running from generator to service panel and the power source (MEP-803A) is the grounding source. (to ground rod) I stated it this way because you have setup a complete breaker panel where you can bond neutral and ground.

Pictures of freezer tag
What size breaker is the freezer on?
what other power items will be used?

Balanced loads is nice, but, close enough will not hurt. Its when its way off say 45 amps one leg and 15 amps other leg, that could use more balancing. This is where the clamp meter helps. To see the draw on each leg.

What about grounding the container itself? Should that be grounded with its own rod/s?

 

[Light in the Dark]

In laws coming over soon, and need some thorough reading so as to avoid them? https://www.wbdg.org/FFC/NAVFAC/DMMHNAV/hdbk419a_vol1.pdf

I would absolutely be grounding that puppy for safety reasons! Takes but a second for it to all go horribly wrong. Its a real good document to peruse, including grounding for lighting, EMPS, determining earth resistance for areas where the ground actually freezes (like AK!), etc. In this instance, I would do some thorough research, as you are working inside a conductor...

I think it was Guyfang a couple years ago that posted a real good document on grounding (and it showed how to use multiple ground rods for certain instances).

 

[Guyfang]

I just uploaded two documents concerning Grounding and Bonding. You will find them in the TM upload section, until an Administrator puts them in the Generator Forum.

 

[Light in the Dark]

Yup, thats the one I remember. Thanks sir.

 

[SalmonSlayer]

Howdy,
OK, with some clarification.
a 40ft container, a MEP-803A as the only power source. Movable to area where it is needed. Then, that would be field style, only power source, drive a ground rod, connect to generator, bonding link in place, that will be your only grounding source. since you are using a regular service panel with breakers, does it have a main service breaker? In the service panel, do not bond ground and neutral, and have 4 wires running from generator to service panel and the power source (MEP-803A) is the grounding source. (to ground rod) I stated it this way because you have setup a complete breaker panel where you can bond neutral and ground.

Pictures of freezer tag
What size breaker is the freezer on?
what other power items will be used?

Balanced loads is nice, but, close enough will not hurt. Its when its way off say 45 amps one leg and 15 amps other leg, that could use more balancing. This is where the clamp meter helps. To see the draw on each leg.

ill try to get some pictures today and get back to you

 

[SalmonSlayer]

ive got the freezer on a 40amp breaker and that's the only thing on that circuit. there are other breakers in the panel though for lights outlets etc... the only other item that's a large draw will be the Vacuum packing machine which is 120V and draws i think about 20amps when its running