Load Bank?

[csheath]

How about using an electric clothes dryer?

Could you take the elements out of the dryer and cool them with a good old box fan.

Thinking about it You could connect two fans together and put the elements in one and yous the other for cooling.

I will help revive this old thread as I conjure up a way to build a load bank. My needs will be to load test and run a MEP-803A

Reason I quote quickfarms here is in my brain storming I came across some clothes dryer elements that are reasonably priced but most if not all seem to be in the 5400W 240V variety. I would like to go with an air cooled design but I'm not sure I would get the desired results with these. My initial thoughts are a duct with 3 of these elements powered through a breaker panel and use breakers as switches. I would install a fan to blow over the elements and they can double as outside heat if I'm working near the generator. It would seem two of these should be a good long run test for burning out the exhaust but I'm thinking 3 of them should be overload. If I go this route I will probably get two and add a couple of 1500W space heaters.

Another thought for resistive heating elements is the auxiliary heat strip kits for heat pump systems. Those cost a bit more but are available in a variety of sizes starting around 3Kw and going as high as 20Kw. Having a 3Kw and two 5Kw sets of these might make a better tester for the 10K generator.

 

[DieselAddict]

If you look at the dryer elements you'll see that modifying them for lower wattage should be straight forward. You'll need a good crimp connection. A small split bold connector will also work. You can shorten them and rewire them into multiple circuits for different loads in the same frame (depending on how they are wound on the frame).

Alternately you can run 2 sets of elements in series to cut the power in half. Run 3 in series to cut them by 66% (assuming 3 equal sets of elements).

Look up "splicing nichrome wire" and you'll see some options for getting creative and having just about any KW load you want.

 

[csheath]

If you look at the dryer elements you'll see that modifying them for lower wattage should be straight forward. You'll need a good crimp connection. A small split bold connector will also work. You can shorten them and rewire them into multiple circuits for different loads in the same frame (depending on how they are wound on the frame).

Alternately you can run 2 sets of elements in series to cut the power in half. Run 3 in series to cut them by 66% (assuming 3 equal sets of elements).

Look up "splicing nichrome wire" and you'll see some options for getting creative and having just about any KW load you want.

I also considered this approach but shortening the elements would decrease the resistance and increase the current draw. Adding a 4th element in series may be a good alternative.

I am also going to keep an eye out for an electric furnace as a base since that would already have the fan and duct. I could add or modify elements as needed.

 

[Chainbreaker]

Csheath - One thought is to use an intact working 240V electric clothes dryer if you have space for one in addition to your 2 space heaters as your incremental add on loads to each leg. During my monthly test I do a load of laundry before switching over to generator, then when I have generator running and switched over to house I put clothes in dryer and let it run for an hour. It pulls 5600 watts (motor & heater elements) and gives my 5 Kw MEP-002a a good load-balanced workout. Towards the end (last 10 min) my dryer cycles heat off & on (tapers off load) in an end of cycle cool down mode. Most dryers have other dryer options that use less wattage (air fluff + various low temp settings) so you can work up to a full load test in increments if needed. In my case its a win-win, clothes get dried and gen set gets a good even workout and no electricity is wasted!

I realize that if you are repairing/load testing a genset you may not want to hook up to house initially. You could look on Craigslist and find a deal on a used clothes dryer to be used as a dedicated shop dryer/load tester. Often people when moving long distances sell appliances fairly cheap and re-buy on the other end rather than paying extra to move old bulky appliances cross country.

 

[Guyfang]

Do not use your house as a load bank until you have worked out the bugs! Take my word for it!!

Some military load banks that are air cooled, put the heating coils, (elements) in a steel tube. A fan is installed on one end, to PULL air through the tube, giving better cooling. Then a switch is installed that only closes, when the air is pulled through the tube. It has a sort of half wing on it. When that switch closes, then, and only then, is the relay/contactor that energizes the heating elements allowed to close. So if the air intake side of the tube is blocked, from a door, paper, plastic or anything else, the switch opens and drops the load from the heater. Prevents you perhaps burning up the heater elements, and or, what ever is next to your homemade load bank. Take a look at the A-427 load bank schematic to see a good example of this set up.

 

[Chainbreaker]

Do not use your house as a load bank until you have worked out the bugs! Take my word for it!!

Good advice!

I should have been more explicit in my dryer suggestion. I only run my genset hooked to house for "monthly exercise runs" when I know my genset(s) are in proper running condition. Using the dryer to put a load on it (while drying laundry) just insures that both 120V legs are more load balanced and helps insure the generator heats up to working temp and burns off any carbon buildup. It helps to have JimC's full digital gauge set to monitor loading on each 120V leg for more accurate load balancing.

Otherwise, you can still use an old dryer to load test a unit by purchasing/building a 220V connection box or spider box coming directly off the generator load terminals (of course with proper genset ground rod grounding). A 220V dryer is built with consumer safety in mind and has the proper airflow already worked out. I've seen used working dryers on Craiglist going for $20 - $50. Cheaper than buying parts a-la-carte.

Anyway, just a thought. Of course a proper mil surplus load bank would be the cats meow!

 

[Triton]

I found a picture of this being used as a load cell on the net!

 

[csheath]

I considered that but I would prefer to have things enclosed, insulated, and safe.

 

[fcbrants]

Load Bank: Water heater elements in a pool?

Here's a crazy thought:

I have an in-ground ("cement pond" type pool. If I purchased hot water heating elements (~ $20.00 each for 5,500 watts on Amazon) & mounted them in a metal strip, then would there be any electrocution danger if I made 100% certain there were NO loose wires? It's my understanding that current will always take the path of least resistance, which in this case, would be through the heating element. I would trip the pool equipment breakers, so there would be no chance of current leaking back to the house through those circuits.

I would suspend the strip right above the surface of the water to keep the elements from burning up.

Does anybody see any problems with this?

Thanks!!

Franko

 

[Dwnorton1]

That sounds scary. The whole element need to be submerged or it will burn out, this will put live conductors within really close proximity with water. Could mount termination box in watertight box and submerge whole thing as long as you put in on GFCI breaker. Might be better to mount elements on a pipe where no chance of contact of wiring and pool. Just add little circulation pump to keep water flowing. I still would not swim with Elle May with either set up though.

 

[fcbrants]

Agreed, Every fiber of my being is screaming "Noooooooo!", and "me and Ellie May already had our bath this week", but would it work & would there be any real danger, even if the elements submerged and the leads went In the Water?

It Definitely falls into the "kids, don't try this at home" category & if I got killed, I would surely earn a Darwin Award, but in all seriousness, wouldn't the current Rather stay within the heating element, even if the leads were all under water?

That sounds scary. The whole element need to be submerged or it will burn out, this will put live conductors within really close proximity with water. Could mount termination box in watertight box and submerge whole thing as long as you put in on GFCI breaker. Might be better to mount elements on a pipe where no chance of contact of wiring and pool. Just add little circulation pump to keep water flowing. I still would not swim with Elle May with either set up though.

 

[Zed254]

I like my $50 used electric stove. I put it on 2 Harbor Freight moving dollies and bought a canvas furniture cover to make it look nice for the neighbors. Total investment is something like $175 (with electrical connectors) and I can get 104% on the power meter of my MEP803A. All that electricity into a swimming pool scares me.

 

[Dwnorton1]

Resistance to ground will be way less than a heater element which with 5500watt element will be 11-12 Ohms. Resistance to ground/pool water will be way less should be -0- but IEEE recommends less than 5 ohms resistance. I too use a cook stove as load bank for my 803. I even use it for 120vac load bank for 831. Feeding with 120vac just cuts output by 50% but is just right for 3kw unit.

 

[Guyfang]

I have hesitated to even mention this story, because it still scares the **** out of me, and embarrises me to admit I even had knowage of it, let alone helped cobble it together.

As a young soldier, I worked for several people who should not have been allowed outdoors without adult supervision. One of them made a "load Bank" out of a 55 gal drum, four six foot ground rods and several 2X4's. He filled the drum up with water, dumped in two bags of salt and mixed it up. He drilled holes in the 2X4's and poked the ground rods through them. It was suposed to keep them "insulated" from one another. He hooked the three phases and I think the N to the four rods. The other end was hooked to the gen set. By raising and lowering this contraption in the water, he could "regulate" the amp draw.

When It really dawned on me what he intended to do with this thing, I made myself not available. I watched from way far away. The water came to a boil RIGHT NOW. The gen set was a 45 KW. It pulled that gen set down until it almost quit. No one would stand within 50 meters of it. I didnt think it was a good idea then, and 44 years later, haven't changed my mind a bit. Water and electricity just do not fit together in my head. No one yet has come out and said so, but I will. I would not do this unless I was trying to get rid of a pool full of sharks, piranha and the Boston Strangler. There are way too many other ways to accomplish the mission. Safe ways. Go to the landfill and pay some good old boy to get you a couple old ovens. Fab something up from them that is safe. I will even loan you the money. Anything but the pool.

 

[coxju04]

The best thing I've found is a 10KW A/C heating element and a fan, and let her rip. The whole thing cost around $50.00 off the Bay

 

[steelypip]

There is a right way to heat water with electricity. Guyfang correctly identifies one of the many wrong ways (yeah, that's scary).

You're on the right track with water heater elements, but you need to put them in something groundable, enclosed and above the water level of the pool. Then you put a pump in front of it pumping water out of the pool into the 'something,' and a line running out of the 'something' into the pool.

Operation would be 1. turn on the pump, 2. verify water flow through the heater, and 3. start generator and apply load as desired.

Normally I'd say just use an electric water heater, but you probably want more granularity of your load bank than that, so you'd need more than two heating elements and it would be ideal if they were a power of two relationship to each other starting at something like 100 watts draw.

What do I use?

I plug my gen set into the house and use the stove. Works quite well, unless somebody forgets the house is running on genset and spins up the heat pump or the microwave while I'm already boiling three pots of water... The ideal stove for this is one of the old GE two-element Calrod units. They don't use a cycling thermostat, but connect two heating elements in series or parallel across 120 or 240v to get the different wattages.

I have some baseboard strip heaters that will eventually be the genset load bank. They'll be mounted inside the mower shed, so can double as mower shed winter heat.

 

[Guyfang]

Steelypip,that would qualify as a safe method.

Yes, there are ways to do this in your pool. Get heating elements that are made to do that. We have installed some for a customer. BUT, they are specially designed for this purpose. THAT means money.

 

[csheath]

Since this thread has resurfaced I will link to what I finally did for my load bank using dryer elements. This made a fairly compact unit I can pick up and move as needed.
https://www.steelsoldiers.com/showthread.php?163190-Homemade-Load-Bank

Still if you have room you can use an electric range which I have seen for free pickup from time to time on Craigslist.

 

[fcbrants]

Thanks to everybody who replied for all of your input, it helps tremendously.

Part of my reasoning for going with the water heater elements is the fact that they will scale well & the pool will make a good heat sink.

I bought a MEP-806B, Not with the intention of trying to re-wire it to 120/240, and Not to use as my personal backup gennie (I have a 12 KW natural gas genset for that), but Only because I love a big diesel genset & this beastie is big enough and modern enough to be extremely interesting to play with.

Steelypip, this sounds great, I can get a metal horse trough (or two) and I'm off to the races.

Thank you!!

Franko

There is a right way to heat water with electricity. Guyfang correctly identifies one of the many wrong ways (yeah, that's scary).

You're on the right track with water heater elements, but you need to put them in something groundable, enclosed and above the water level of the pool. Then you put a pump in front of it pumping water out of the pool into the 'something,' and a line running out of the 'something' into the pool.

Operation would be 1. turn on the pump, 2. verify water flow through the heater, and 3. start generator and apply load as desired.

Normally I'd say just use an electric water heater, but you probably want more granularity of your load bank than that, so you'd need more than two heating elements and it would be ideal if they were a power of two relationship to each other starting at something like 100 watts draw.

What do I use?

I plug my gen set into the house and use the stove. Works quite well, unless somebody forgets the house is running on genset and spins up the heat pump or the microwave while I'm already boiling three pots of water... The ideal stove for this is one of the old GE two-element Calrod units. They don't use a cycling thermostat, but connect two heating elements in series or parallel across 120 or 240v to get the different wattages.

I have some baseboard strip heaters that will eventually be the genset load bank. They'll be mounted inside the mower shed, so can double as mower shed winter heat.

 

[fcbrants]

Thanks CS, I took a hard look at your load bank (nice piece of kit!!) before posting in this thread & decided it would be too cumbersome to cobble enough of these elements together to "feed the beast" with 60 kW++ of load & keep them from burning each other up.

Since this thread has resurfaced I will link to what I finally did for my load bank using dryer elements. This made a fairly compact unit I can pick up and move as needed.
https://www.steelsoldiers.com/showthread.php?163190-Homemade-Load-Bank

Still if you have room you can use an electric range which I have seen for free pickup from time to time on Craigslist.