help me understand my gen's output

[boosteddsm92]

Just acquired a mint Honda EM5000SX. Relevant snip of manual below. I was planning on putting in an interlock and breaker for the generator. If I'm understanding correctly, if I use the 240v plug to power my panel it's only going to give me 18.8A. I want to power at least my well pump, 2 fridges, a freezer, and a bunch of outlets/lights. If all I'm going to get is 18.8A then it would barely, and maybe not even, power my well pump. Is my thinking correct? If so, I'll unload it and get a more appropriately sized unit. I'm thinking an military MEP-803A or something.

 

[AngryBeaver]

yes that is correct. your well pump shouldn't pull anywhere near 18 amps. it should pull 8-10 on each leg at most. They are usually under 5amps unless you have a 200' well. that gives you 8-10 amps available on each leg to power the fridge, lights, and whatnot. a 5K gen will run most of the house, just not all at once.

amp your panel with the well pump running and nothing major like electric heat, electric stove and see what the total draw is. it should be realistically about 18-25 amps per leg. '

if you want a gen to run run everything in your house simultaneously then you need a BIG generator. like 15-20W depending on electric or gas stove, furnace, hot water heater, etc

most permanent stand by house units are in the 10Kw-11kw ranges fwiw. those are mounted to a pad and a transfer switch ready to rock whenever the power goes out, not a roll the honda out and plug in a few things to get you by

 

[wyliesdiesels]

The problem with running a well or other motor load on a gen is the startup aka in-rush current.

If the generator cant handle the surge during startup of the motor, then the pump wont start.

 

[sberry]

How big is the well? 5k is a lot. With a well a hp or less it will work fine. When mine is out I run the well first then switch the rest on so every fridge and freezer doesn't come on with it when the switch is thrown.

 

[OccupantRJ]

I ran lights, fridge, freezer, satellite tv, and other small loads with no issue at least 6 times in the past. Trying to use a microwave would surge the governor on the unit more than any of the previous items. A coffee maker was second on making it work hard. My unit is 5000 watts peak load.

 

[sberry]

A 5 is nice because it's economical to run. So much so it doesn't need to be shut down for long outages. Big difference in work and cost between 20 gallons or 5 a day.

 

[Falcon67]

A 5 is nice because it's economical to run. So much so it doesn't need to be shut down for long outages. Big difference in work and cost between 20 gallons or 5 a day.

Our 6500 uses right at 5 gallons over about 7 hours at 1/2 load. A 5K might go 10+ at 1/2 load. Even our 3500 used more than 5 a day at half~2/3 load. That one about 8 hr on 3 1/2 gallons IIRC.

We use a 6500 on the race trailer so we don't have to budget power - 15K AC, water pump for sink/pot, 700w microwave, coffee pot, battery charger, etc.

 

[boosteddsm92]

Thanks guys, I'll do some testing w/it and see if it will fit my needs. IIRC my well is about 110'.

 

[sberry]

Whats the hp? If its 240V about 6 A or even less for a common residential.
smaller one could run on 120V

 

[boosteddsm92]

Whats the hp? If its 240V about 6 A or even less for a common residential.
smaller one could run on 120V

Just found the sticker, it's a 1/2 HP 240v, 3.7 amp,. 37kW

 

[sberry]

A 5K will run this and the other stuff to stay afloat no problem.

 

[Bretny]

Even if it doe what you need sell it. The mep800 series of generators are solid units and get way better fuel economy than your current generator. The 802a gets better fuel economy per KW than a honda eu2000i.

My 802a runs my well pump, heat pump water heater, lights and the oven all at the same time. I can even use the electric dryer...try that with a 5kw consumer grade generator.
If your serious about having power when other dont then you need to get away from consumer grade products as they are mostly all built on price point. The MEP generators are built with a purpose in mind and thats to produce power where others cant.

 

[wyliesdiesels]

Even if it doe what you need sell it. The mep800 series of generators are solid units and get way better fuel economy than your current generator. The 802a gets better fuel economy per KW than a honda eu2000i.

My 802a runs my well pump, heat pump water heater, lights and the oven all at the same time. I can even use the electric dryer...try that with a 5kw consumer grade generator.
If your serious about having power when other dont then you need to get away from consumer grade products as they are mostly all built on price point. The MEP generators are built with a purpose in mind and thats to produce power where others cant.

The EU2000i is .28 gph
The 802a is .57 gph

.28/2 = .14
.57/5 = .11

3 hundredths of a gallon is not much difference.

 

[Bretny]

None the less its still a difference and a 802 goes to 5kw for about the same price as a new eu2000 with out the gas issues.
Also i should note that your caluclation is based on the running watts for the 802 and the starting watts for the eu2000.

Its more like.
eu2000 .175
802a .11

 

[wyliesdiesels]

None the less its still a difference and a 802 goes to 5kw for about the same price as a new eu2000 with out the gas issues.
Also i should note that your caluclation is based on the running watts for the 802 and the starting watts for the eu2000.

Its more like.
eu2000 .175
802a .11

true. I missed that.

Is there a higher KW rated MEP unit?

Im looking for 10Kw-20KW model...

 

[boosteddsm92]

true. I missed that.

Is there a higher KW rated MEP unit?

Im looking for 10Kw-20KW model...

MEP-803A is 10kW, any higher MEP is 3 phase only as far as I understand. Specs for both:

https://greenmountaingenerators.com/manuals-and-support/mep-802a-manuals/

https://greenmountaingenerators.com/manuals-and-support/mep-803a-manuals/

 

[Bretny]

No its not 3 ph only. The 3ph only can start in higher wattage units. The 802/803 have 3ph capabilities with the flip of a switch.
The 803 is rated for 10kw continious. Continuous is different than the consumer rating of running watts. The 803 would be more like a 12kw running consumer grade unit. Two of there other benefits are they run at 1800rpm and have an aux fuel system. The aux system allows the generator to **** fuel out of a external source, jerry can, 55gal drum, home heating oil tank.

 

[boosteddsm92]

No its not 3 ph only. The 3ph only can start in higher wattage units. The 802/803 have 3ph capabilities with the flip of a switch.

He was looking for 10kW-20kW. I said the 803 is 10kW and any higher MEP is 3 phase only.

 

[Bretny]

Yes you did. Sorry i missed that.
Just checked the 804 and 805 spec. There both 3ph units and i doubt you need the 30kw of the 805. Even 15kw is a huge load for a single house to use. Why do you need such a large unit?

 

[The Tool Tyrant]

My Jen's output has been almost non-existent...she blames it on her migranes.

 

[sberry]

The "mint" Honda you already have should be ideal for this. The well can be a deal breaker in some cases but this is only 1/2 hp, very good for survival.
You can power a hundred outlets and lights, use only some at a time. I might make sure all 3 fridges are not on the same leg. As I mentioned, if the power has been down for a while and every cooling unit is going to come on at once I run the well first, fill the tank so it isn't starting with the rest of it when you first plug it in. Once it all catches up its not a big deal and if you can live without electric water heater, electric cloths dryer and keep to a modest window unit if you have to for AC, run small appliances 1 at a time the 5 is right.
I put a 4.5 with no well between 2 houses and not a problem, can carry on with only minimal concern, can even use the range top some in one.

 

[sberry]

I have a welding machine for one place, they have a lot of start poop and if I let it all catch up will run the place, 5 fridge/freezers and will run the well which is 15 run amps. I turn off air compression and any electric heat.
The problem with it is that its greedy when the well isn't on, 16 hp blazing away to keep the lights and freezers on. I recently got a genset, I might come up with some scheme related to water pressure. I would like to come up with a couple more small units, 5 K or so for other stuff.

 

[boosteddsm92]

Thanks for all the input, I appreciate it. Now here's what I'm thinking.

When utility is lost, turn off main in main panel. Turn off all breakers except for the 100a feeding garage subpanel. Turn off all breakers in garage panel except for the main. Start generator. Turn on generator 30a breaker. Start selectively turning on breakers in main and/or garage panels. Any reason why backfeeding through a subpanel in this manner won't work? I plan on rearranging breakers and doing an interlock in the main so please no comments about backfeeding danger.

 

[mm08822]

When you state "back-feeding through a sub panel", I assume you mean the generator is feeding the subpanel directly. If so, having the interlock in the main panel is useless when the generator backfeed cb is in the sub panel.

To be able to selectively feed any of the loads in house and garage safely, you need the interlock in the main panel and the generator feeding the main panel to make proper use of an interlock with the utility connection and generator input.

 

[Bretny]

Thats how im setup right now. Sub pannel in detached garage. My friends whos an electrician said theres no legal way to do it. Short of running a new wire from near thst sub pannel to the main pannel.
Also an interlock on that sub pannel would make it not have power all the time unless under generator power.

 

[boosteddsm92]

When you state "back-feeding through a sub panel", I assume you mean the generator is feeding the subpanel directly. If so, having the interlock in the main panel is useless when the generator backfeed cb is in the sub panel.

To be able to selectively feed any of the loads in house and garage safely, you need the interlock in the main panel and the generator feeding the main panel to make proper use of an interlock with the utility connection and generator input.

Yep, I thought about that after I posted, can't use an interlock.

 

[wyliesdiesels]

The only way to do this is to have the generator feed the main service panel.

 

[Firebrand]

Plus 1 on the MEP 803A unit! Rated 10kW by the military but puts out over 12.5kW all day and night. Great machine that just won't quit.

Run the wires to the main panel for either an interlock or transfer switch. The transfer switch must be sized to the house panel capacity, not the generator capacity.

Also, make sure your generator is not grounded separately but uses the house ground otherwise you have created another path for current flow.

YMMV. Some assembly required.

 

[wyliesdiesels]

Plus 1 on the MEP 803A unit! Rated 10kW by the military but puts out over 12.5kW all day and night. Great machine that just won't quit.

Run the wires to the main panel for either an interlock or transfer switch. The transfer switch must be sized to the house panel capacity, not the generator capacity.

Also, make sure your generator is not grounded separately but uses the house ground otherwise you have created another path for current flow.

YMMV. Some assembly required.

To clarify on this- he is talking about grounding electrodes, though the earth is a poor conductor of electricity and hardly any current would flow through the earth from gen ground rod to panel ground rod.

Make sure generator DOES NOT have a bonded neutral. This requires running a 4-wire feeder to it.