Acquired Another MEP-802A - A Couple of Questions

[Digger556]

Update.. Finished the wiring for the electrical connection. Moved the unit closer to the house, dumped in the rest of the Seafoam in and filled the tank with fresh road diesel.

The house is currently running off the gennie with no issues. Pic of the monitoring panel in the house for load readings. Yes, I am stressing it on purpose If my math is right, this is a 7.8KW load.

View attachment 907114

L1 = 2292 watts
L2 = 1596 watts

Total = 3.9 kW

 

[Ray70]

I assume you were thinking 240V x 32.4A , not 120V per line.

 

[Blockwarden]

I assume you were thinking 240V x 32.4A , not 120V per line.

If I was thinking right the data plate on the unit states 26A at 240V. I admit that I suck at math so there may be a grievous error on my part.

Still amazing that we can run the entire house no problem with the heat pump and all. Guess that I'll need to try again and start turning on more stuff in the house. I have a couple of 1,500W space heaters, throwing one on each leg may help.

On the smoke issue. It is still there, but appears that it has lightened a bit (not that it was thick to begin with). Perhaps my other main unit does the same thing and I just never noticed since it is in a lean-to shelter with a 90 on the output that directs the exhaust backwards at a 45 degree angle to keep the stink from being blown back in my face by the cooling fan.

 

[Blockwarden]

Ok, hate to say it but I consulted ChatGPT, according to it my original math was correct (and I do suck at math). Here's what it said:

"If you have readings of 19.1 amps on one leg of the 120-volt circuit and 13.3 amps on the other leg, and you're interested in finding the total current on the 240-volt circuit, you can add the currents on the two legs together.
Total current on the 240-volt circuit = Current on one leg + Current on the other leg
Total current = 19.1 amps + 13.3 amps = 32.4 amps
So, the total current on the 240-volt circuit is 32.4 amps. This is the combined current flowing through both legs of the 240-volt circuit."

I also asked it to convert this to watts:

"To convert the total current of 32.4 amps at 240 volts to watts, you can use the formula:
Power (in watts) = Voltage (in volts) × Current (in amps)
Power = 240 volts × 32.4 amps
Power = 7,776 watts
So, the total power consumption in this case is 7,776 watts, or 7.776 kilowatts (kW)."

It also took the time to inform me of the the problems associated with unbalanced loads. Gotta love AI

 

[fb40dash5]

Ok, hate to say it but I consulted ChatGPT, according to it my original math was correct (and I do suck at math).

If you put a 1200 watt heater on one leg, and nothing on the other leg, and were running at 120v, you'd see 10A draw on one leg, and 0A on the other.

Would your 1200w heater be drawing 1200w, or 2400w?

 

[Blockwarden]

If you put a 1200 watt heater on one leg, and nothing on the other leg, and were running at 120v, you'd see 10A draw on one leg, and 0A on the other.

Would your 1200w heater be drawing 1200w, or 2400w?

Did you mean 240V?

10A draw on one leg, 1,200W, since the other leg is 0W.

When considering a 200A, 240V service panel, that means that you have 100A available individually to the X and Y hot branches (120V) that have a shared neutral and ground.

 

[2Pbfeet]

Ok, hate to say it but I consulted ChatGPT, according to it my original math was correct (and I do suck at math). Here's what it said:

"If you have readings of 19.1 amps on one leg of the 120-volt circuit and 13.3 amps on the other leg, and you're interested in finding the total current on the 240-volt circuit, you can add the currents on the two legs together.
Total current on the 240-volt circuit = Current on one leg + Current on the other leg
Total current = 19.1 amps + 13.3 amps = 32.4 amps
So, the total current on the 240-volt circuit is 32.4 amps. This is the combined current flowing through both legs of the 240-volt circuit."

I also asked it to convert this to watts:

"To convert the total current of 32.4 amps at 240 volts to watts, you can use the formula:
Power (in watts) = Voltage (in volts) × Current (in amps)
Power = 240 volts × 32.4 amps
Power = 7,776 watts
So, the total power consumption in this case is 7,776 watts, or 7.776 kilowatts (kW)."

It also took the time to inform me of the the problems associated with unbalanced loads. Gotta love AI

Please don't rely on ChatGPT for knowledge or math. It messes up regularly. If you want a love letter to a girlfriend: go for it.

You have two 120V supplies. (With 240 between them, but that is not relevant.)

Your gauges are showing you what you need, and the math is simple.
Gauge 1 120V and 19A
Gauge 2 is 120V and 13.4A.

Power is volts times amps.
120X(19+13.4)=3,888W

@Digger556 had the math correct above.

All the best,

2Pbfeet

 

[Blockwarden]

Ok, I'll take it.

Goes contrary to my experience wiring a house and the addition to mine. I'll run it by my friend that is a retired electrician (he may just call me an idiot ).

 

[2Pbfeet]

Sounds like a good source of information!

All the best,

2Pbfeet

 

[Blockwarden]

Ok.. Got feedback from the electrician.. I totally missed the fundamental fact that when dividing current from 240V into two 120V legs that the Amperage available on the on the 120V legs doubles (200A @ 240V = 400A @ 120V). I should know better, but my tesla coil building days are more than 20 years behind me and I have not gotten any younger.

Dang, now I feel a remedial level of stupid

 

[Digger556]

Look at the diagram in the upper left box. A simple DC circuit with a 1.5 volt battery and a single load that pulls 1 amp. There is an outflow of 1 amp on the upper wire, 1 amp through the load, and a return flow of 1 amp on the lower wire. Total power draw of the load is 1.5V x 1.0 A = 1.5 watts. You only measure current at one spot to calculate the power of the system. You don't count the upper flow as 1 amp and add it to the return flow of 1 amp.

Now, let's take 2 of those circuits and wire them together with a common middle wire, like in the diagram at the lower left. Both circuits are exactly the same, but share a single wire in the middle. Since 1 amp of current is flowing left through the middle wire and 1 amp is flowing right, they cancel each other and there is no total current on the middle conductor. The current at any node in the circuit must sum to zero. Electrons are not created or destroyed.

The diagram on the right is your generator. It is just like the dual battery circuit. Essentially two 120V windings are sharing a common wire in the middle. You get 240V when you connect L1 and L3 because you are combining the two "batteries". To calculate power, you must look at the amperage and the voltage through a given load. In this case, you can simplify the loads to what can be measured on L1 and what is measured on L3, pretending there is no 240V loads. There may be a 240V, but it doesn't change the notion that it can be simplified this way.

Because load 1 has net voltage of 120V and a net amperage of 19.1 A, you multiple 19.1 x 120v to get 2292 watts. The current leaves Load 1, but because Load 2 only needs 13.3 amps, the left over 5.8 amps returns home on the neutral line, back to the L1 windings, and 13.3 amps continues on to the Load 2. Load 2 sees 13.3 amps at 120V net voltage, so power is 13.3 amps x 120v or 1596 watts. Total load on the generator is 3,888 watts.

 

[CallMeColt]

Even if it sat inside, keep an eye on all the rubber. Time likes to break all that stuff down, especially is the unit saw any JP8.

 

[Light in the Dark]

I have to wonder if this is true across the board, or do things differ across the US? Here in New England there is a difference between #1 and #2 Diesel, The viscosity. #1 is blended with Kerosene to lower it's viscosity for winter use, which also gives it a higher Cetane rating.
For the tax Vs. no tax, anything Red is non-taxed ( HHO, off-road diesel and at one point in the past, Kerosene )
One difference here in RI is that there are no pumps where you can purchase off-road diesel with dye in it. You can only buy it in 55gl drums or have it delivered directly to your site and pumped into a storage tank or construction equipment. I have seen off-road diesel available at the pump down south more in VA, TN and KY I believe.

Took a roadtrip through PA/NYS in the last few weeks and I saw both off road diesel available by pump (non agricultural location in the immediate area) and a different station with ethanol free unleaded. I think the unleaded was labeled 'rec fuel' from memory.

 

[Mullaney]

Took a roadtrip through PA/NYS in the last few weeks and I saw both off road diesel available by pump (non agricultural location in the immediate area) and a different station with ethanol free unleaded. I think the unleaded was labeled 'rec fuel' from memory.

.
Interesting @Light in the Dark . I happened to be north of the city last weekend and just off Interstate 77 at Exit 36 at the Shell Station - both Ag Diesel and Ethanol Free Gas pumps were off at the edge of the concrete...

I was impressed. Definitely worth having the good gas for lawn mowers and go-carts! It's a half hour drive but worth using that in small engines.

.

 

[Ray70]

Yes! last couple years I have gotten ethanol free gas in upstate NY and VA, got about 25Gl each time, added stabilizer as soon as I got it home and worked great for yard equipment etc. No issue at all storing it for over a year.
Have seen it in 91 octane and 87 depending on location.