3 Phase to Single Phase Step Down Transformers

[3gunguy]

I don't understand why you would need 18 KW to run your house. I have a very large house, totally electric. I have an MEP003A, a 10 kw machine that feeds a 400 amp square D manual transfer switch. I don't have any load switching at all. We have frequent power outages because we live remotely on 40 acres in the mountains surrounded by national forest. Some outages have lasted a week or more, both summer and winter. When I start the MEP003A, it is business as usual. I don't pay any attention to what is turned on. The genset handles it all, albeit somewhat noisy. Just because there are a lot of things in the house that pull power, doesn't mean that they are all on at the same time. We run the HVAC, dryer, washer, dishwasher, etc. and have never had any problems. I like the MEP003A because it is very simple, easy to service and is air cooled, so no potential problems with liquid-based cooling systems. It puts out both single and three-phase power. It uses about 1 gallon of diesel per hour at full load and is very easy to start. Even my wife can start it without problems. I purchased it at auction in 2009 and it has run almost completely trouble-free since then. It was never rebuilt by the military and has 8085 total hours on it. It was freshly back from Iraq when I got it and is trailer-mounted, which makes it nice to be able to move it easily around our property when power is needed remotely. I previously also used it in three-phase to power a lot of three-phase power tools in my shop before a installed a rotary phase converter. Talk to other people that currently use 10 kw MEP gensets to power their houses for power.

Gary,

I hope you are right. I have not yet received the generator. I am having a high wattage plug and breaker installed next week. I guess I will need to hook it up and see what it runs.

So far though, the electrician and I found the following.

Home: 2260 sq feet in south florida summer heat.

A/C runs at a bout 18 amps
2 full size fridges and a chest freezer plugged in, couple tv's and lights (LED) run about 7 amps
1.5 HP pool pump runs at 8 amps
Hot water heater runs at about 18.5 amps

If I turn on the stove/oven, a coffee maker and run the microwave....we are going to have some serious issues I presume. Unless I am missing something. That is why I think load balancing on a gennie this size may be an issue.

Thoughts?
Peter

 

[Scoobyshep]

Gary,

I hope you are right. I have not yet received the generator. I am having a high wattage plug and breaker installed next week. I guess I will need to hook it up and see what it runs.

So far though, the electrician and I found the following.

Home: 2260 sq feet in south florida summer heat.

A/C runs at a bout 18 amps
2 full size fridges and a chest freezer plugged in, couple tv's and lights (LED) run about 7 amps
1.5 HP pool pump runs at 8 amps
Hot water heater runs at about 18.5 amps

If I turn on the stove/oven, a coffee maker and run the microwave....we are going to have some serious issues I presume. Unless I am missing something. That is why I think load balancing on a gennie this size may be an issue.

Thoughts?
Peter

Name of the game is load balance. Do you really think you'll have everything running at once? You can go smaller unless you think you'll be cooking Thanksgiving dinner while showering while someone's making coffee and microwaving a burrito.

The other thing to think of is wetstack due to underload

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[Ray70]

Also consider fuel consumption. the 803 will be way more economical than a 15kw or 30kw.
However you are right that you may encounter an issue if your hot water tank is heating, your wife is making coffee and heating up a muffin in the microwave, and the AC kicks on!
Slight load management may be required, but that 803 may surprise you.
You won't know for sure until you set up and test things.
Additionally IF your AC turning on becomes the gating factor, consider adding a $200 soft start on the condensor.

 

[WWRD99]

Gary,

I hope you are right. I have not yet received the generator. I am having a high wattage plug and breaker installed next week. I guess I will need to hook it up and see what it runs.

So far though, the electrician and I found the following.

Home: 2260 sq feet in south florida summer heat.

A/C runs at a bout 18 amps
2 full size fridges and a chest freezer plugged in, couple tv's and lights (LED) run about 7 amps
1.5 HP pool pump runs at 8 amps
Hot water heater runs at about 18.5 amps

If I turn on the stove/oven, a coffee maker and run the microwave....we are going to have some serious issues I presume. Unless I am missing something. That is why I think load balancing on a gennie this size may be an issue.

Thoughts?
Peter

I don't know how you're calculating that load...the ac compressor start up amps is probably close to 100 amps...the pool pump who knows...I'd do a soft start on the ac and pool pump. They will knock that down to about a third in start up load. I'd bet the 803 can handle it though. You can run 55 amps at 220. Even still if you have to turn off your pool pump in a hurricane would that be the worst thing to deal with? I see you talked about a plug in setup...do a manual switch that is hard wired as a plug can be very dangerous or corrode.

 

[DieselAddict]

Gary,

I hope you are right. I have not yet received the generator. I am having a high wattage plug and breaker installed next week. I guess I will need to hook it up and see what it runs.

So far though, the electrician and I found the following.

Home: 2260 sq feet in south florida summer heat.

A/C runs at a bout 18 amps
2 full size fridges and a chest freezer plugged in, couple tv's and lights (LED) run about 7 amps
1.5 HP pool pump runs at 8 amps
Hot water heater runs at about 18.5 amps

If I turn on the stove/oven, a coffee maker and run the microwave....we are going to have some serious issues I presume. Unless I am missing something. That is why I think load balancing on a gennie this size may be an issue.

Thoughts?
Peter

With a modest amount of load management a 803 should handle everything you need to get you through an outage. I have an 803 here and its too much for my house. Can't keep enough load on it to prevent wetstacking. Now I run it only to charge batteries or run high current appliances. The inverter handles all the critical loads including a 120v room AC that cools the majority of the house (1650 sq/ft).

 

[kayak1]

Also consider fuel consumption. the 803 will be way more economical than a 15kw or 30kw.
However you are right that you may encounter an issue if your hot water tank is heating, your wife is making coffee and heating up a muffin in the microwave, and the AC kicks on!
Slight load management may be required, but that 803 may surprise you.
You won't know for sure until you set up and test things.
Additionally IF your AC turning on becomes the gating factor, consider adding a $200 soft start on the condensor.

For heating water, a heat pump water heater can really reduce load. Mine is on a 30amp breaker, but peaks at under 300 watts running in heat pump mode.

 

[DieselAddict]

Something else to consider is in the civilian world the 803 would be rated at 12.5-13kw. You don't want to run it quite THAT hard all the time but don't worry if you run it to 10kw for long periods. It should live for that.

 

[rickf]

Load management during emergencies is simple common sense. Using the figures you gave I would switch off the pool pump for the duration of the outage, period. The hot water heater would be switched off during times I am cooking or using high draw kitchen appliances. Once done in the kitchen switch the heater back on. The A/C I would leave on since turning it off would make the house humid and then it is going to work even harder to dry out the house before it can cool the house so A/C is left alone. Just these simple things would alleviate any power problems. I am not trying to sound like a butthole but when you live in a place like that you learn to live by certain rules. Mark the breakers and switches for your wife as to what and when they should be off. Also make a checklist. This is something all people should have for emergencies, when the lights go out and the wind is howling and rain is pouring you are not thinking straight, nobody is. Checklists will maintain order.

 

[87cr250r]

If the bigger unit is available I see no reason not to run it. We run our generators at 10% load for 99% of their run time and they do fine. The big 8.1L engines got to burning oil but made it to 35k hours run-time. We replaced with 4.5 liter engines. Fuel consumption doesn't change much, they all burn around 1.5 gph when supporting 10kW.

 

[Farmitall]

Load management during emergencies is simple common sense. Using the figures you gave I would switch off the pool pump for the duration of the outage, period. The hot water heater would be switched off during times I am cooking or using high draw kitchen appliances. Once done in the kitchen switch the heater back on. The A/C I would leave on since turning it off would make the house humid and then it is going to work even harder to dry out the house before it can cool the house so A/C is left alone. Just these simple things would alleviate any power problems. I am not trying to sound like a butthole but when you live in a place like that you learn to live by certain rules. Mark the breakers and switches for your wife as to what and when they should be off. Also make a checklist. This is something all people should have for emergencies, when the lights go out and the wind is howling and rain is pouring you are not thinking straight, nobody is. Checklists will maintain order.

Check lists is right!
And post them conspicuously at the breaker panel. I did this years ago with step by step instructions for my wife in case I was not home. Labeled the breakers to be turned off and how to back feed the panel using a double male cord I made. This was for a 5500 watt gasoline powered set.

Step 1. Turn off the main breaker
Step 2. Turn OFF the main breaker.
Step 3. TURN OFF THE MAIN BREAKER!!!!! Then turn off the breakers marked with red. This was done for load reduction and maintaining balance on the busses.

Step 4. Plug in the double male cord, it only goes one way. One end is a twist lock the other fit the dryer plug. Can't possibly screw it up.
Step 5. Check the oil level on the generator dipstick. Make sure breaker on the generator is OFF.
Step 6. Check the gasoline in the tank, top off if needed.
Step 7. Turn the ignition switch to ON and move the choke lever to the left.
Step 8. Pull the starter rope and when the generator starts, move the choke lever all the way to the right.
Step 9. Let the generator warm up for a couple of minutes, then turn the breaker on the side to ON.

We actually kept lower wattage bulbs to install in the ceiling lights. They were the can type floods so we would remove the spots and install 25W bulbs. Dim, yes, but plenty to navigate the house at night if needed and minimal load.

 

[Scoobyshep]

Check lists is right!
And post them conspicuously at the breaker panel. I did this years ago with step by step instructions for my wife in case I was not home. Labeled the breakers to be turned off and how to back feed the panel using a double male cord I made. This was for a 5500 watt gasoline powered set.

Step 1. Turn off the main breaker
Step 2. Turn OFF the main breaker.
Step 3. TURN OFF THE MAIN BREAKER!!!!! Then turn off the breakers marked with red. This was done for load reduction and maintaining balance on the busses.

Step 4. Plug in the double male cord, it only goes one way. One end is a twist lock the other fit the dryer plug. Can't possibly screw it up.
Step 5. Check the oil level on the generator dipstick. Make sure breaker on the generator is OFF.
Step 6. Check the gasoline in the tank, top off if needed.
Step 7. Turn the ignition switch to ON and move the choke lever to the left.
Step 8. Pull the starter rope and when the generator starts, move the choke lever all the way to the right.
Step 9. Let the generator warm up for a couple of minutes, then turn the breaker on the side to ON.

We actually kept lower wattage bulbs to install in the ceiling lights. They were the can type floods so we would remove the spots and install 25W bulbs. Dim, yes, but plenty to navigate the house at night if needed and minimal load.

Please for the sake of safety get rid of the suicide cord.

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[Farmitall]

Please for the sake of safety get rid of the suicide cord.

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I understand the safety aspect of using that type of cord, that's why steps 1-2 and 3 were to shut off the mains.

It's only been used a couple of times over a 14 year period but not giving it up, its a viable and quick way to get power.

I've got friends that work for the power company as high line guys and even they run that type of cord for short periods of outage.

 

[Scoobyshep]

I understand the safety aspect of using that type of cord, that's why steps 1-2 and 3 were to shut off the mains.

It's only been used a couple of times over a 14 year period but not giving it up, its a viable and quick way to get power.

I've got friends that work for the power company as high line guys and even they run that type of cord for short periods of outage.

I've spent 20 years everywhere from electrical to engineering 24 volt to 32kv. I see them all the time, a properly gendered inlet cord is easy and so much safer. Following a set of rules is known as an administrative control, these are the least preferred solutions as they are easy to defeat. I am glad to hear you've never had an accident with it, and I hope you never do.

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[rickf]

Back feeding a panel where you have to remember to turn off the main is illegal no matter where you are. There are simple panel covers made just for doing this that have a back feed breaker designed to feed in that direction PLUS, You cannot feed the panel from the generator unless an interlock slide has been moved, the only way to move that slide is to turn off the main before it will allow you to turn on the back feed. This protects all the guys working on the line because you are not feeding 240 into their line, you are feeding many thousands of volts after it feeds backwards through the step down transformer and that steps it up to main supply line voltage. And if your friends from the power company are using suicide cords they had better not brag about it!!!!!! It WILL cost them their jobs!

 

[3gunguy]

For heating water, a heat pump water heater can really reduce load. Mine is on a 30amp breaker, but peaks at under 300 watts running in heat pump mode.

Tell me more! I saw these things but it looked like maybe it draws the 4500 watts when it runs but it was just more efficient so it didnt run as long....maybe I mis understand how those work altogether!

 

[Scoobyshep]

Tell me more! I saw these things but it looked like maybe it draws the 4500 watts when it runs but it was just more efficient so it didnt run as long....maybe I mis understand how those work altogether!

He must have a hybrid heatpump/ element style unit

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[3gunguy]

Name of the game is load balance. Do you really think you'll have everything running at once? You can go smaller unless you think you'll be cooking Thanksgiving dinner while showering while someone's making coffee and microwaving a burrito.

The other thing to think of is wetstack due to underload

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I totally get it and understand but I envision having the A/C running at some point in the morning when it heats up, the coffee maker is sitting on the counter keeping my wife's Cafecito hot and the water heater kicks on by itself while she is cooking eggs for the baby. All that while I am at work and bam...things go south with the generator and we are hosed. Just trying to avoid all that by ensuring I have enough that it doesn't matter at the end of the day. Hassle mitigation attempt. I am not the sharpest knife in the drawer and I am worse with electricity.

 

[3gunguy]

He must have a hybrid heatpump/ element style unit

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Yes! I am just curious about how they actually work in regards to current draw. I may be mistaken in how I think they work.

 

[3gunguy]

For heating water, a heat pump water heater can really reduce load. Mine is on a 30amp breaker, but peaks at under 300 watts running in heat pump mode.

I found this.... link about how they work. It does still draw the full 4500 when in high demand but runs just the pump during low use times....

How it Works — Heat Pump Water Heaters (HPWHs)

www.energystar.gov

 

[Scoobyshep]

I totally get it and understand but I envision having the A/C running at some point in the morning when it heats up, the coffee maker is sitting on the counter keeping my wife's Cafecito hot and the water heater kicks on by itself while she is cooking eggs for the baby. All that while I am at work and bam...things go south with the generator and we are hosed. Just trying to avoid all that by ensuring I have enough that it doesn't matter at the end of the day. Hassle mitigation attempt. I am not the sharpest knife in the drawer and I am worse with electricity.

If thats what you feel you need to be comfortable. Just making sure you are aware of all the variables involved. Underload wetstacking, fuel consumption etc. Granted my setup is oversized (it is what was available at the time) I know im gonna burn at least a gallon an hour and every big outage I need to do a maintenance load bank. Since installing, we haven't had a major hurricane outage (the state of Florida owes me a beer for the hurricane repellant) so it's been more of a scheduled load bank to keep things at the ready

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