Forums

Loading up a 36kW transformer

Started by Yzordderrex October 7, 2013
I need to load up a 36kW 3 phase 240v (output) transformer to do a heat run=
.  I looked at having some inductors wound, but that was about $4k.  I've l=
ooked at custom load bank, also about $4k.  I can run three electric water =
heaters ($250.00 each)and discharge about 90 gals an hour of hot water.  Th=
e eagle glo-coils are not manufactured anymore - what a shame.  I've looked=
 at immersion heaters and also stuffing a 50 gallon drum with elements from=
 a stove.

So far I like the electric water heaters the best.  I can load to about 27k=
W and make up the rest with some big wirewounds I have kicking around. but =
looking for any alternate methods before I go to boss with the water heater=
 idea.

Any ideas?

Bob
Yzordderrex <powersupplyguy@netzero.net> wrote:
> I need to load up a 36kW 3 phase 240v (output) transformer to do a heat run. I looked at having some inductors wound, but that was about $4k. I've looked at custom load bank, also about $4k. I can run three electric water heaters ($250.00 each)and discharge about 90 gals an hour of hot water. The eagle glo-coils are not manufactured anymore - what a shame. I've looked at immersion heaters and also stuffing a 50 gallon drum with elements from a stove. > > So far I like the electric water heaters the best. I can load to about 27kW and make up the rest with some big wirewounds I have kicking around. but looking for any alternate methods before I go to boss with the water heater idea. > > Any ideas?
rent a load bank from a generator rental/testing company.
Den mandag den 7. oktober 2013 17.22.29 UTC+2 skrev Yzordderrex:
> I need to load up a 36kW 3 phase 240v (output) transformer to do a heat r=
un. I looked at having some inductors wound, but that was about $4k. I've= looked at custom load bank, also about $4k. I can run three electric wate= r heaters ($250.00 each)and discharge about 90 gals an hour of hot water. = The eagle glo-coils are not manufactured anymore - what a shame. I've look= ed at immersion heaters and also stuffing a 50 gallon drum with elements fr= om a stove.
>=20 >=20 >=20 > So far I like the electric water heaters the best. I can load to about 2=
7kW and make up the rest with some big wirewounds I have kicking around. bu= t looking for any alternate methods before I go to boss with the water heat= er idea.
>=20 >=20 >=20 > Any ideas? >=20 >=20 >=20 > Bob
a few of something like this?=20 http://www.harald-nyborg.dk/p7988/9kw-industrivarmeblaeser -Lasse
On 10/7/2013 10:46 AM, Cydrome Leader wrote:
> Yzordderrex <powersupplyguy@netzero.net> wrote: >> I need to load up a 36kW 3 phase 240v (output) transformer to do a heat run. I looked at having some inductors wound, but that was about $4k. I've looked at custom load bank, also about $4k. I can run three electric water heaters ($250.00 each)and discharge about 90 gals an hour of hot water. The eagle glo-coils are not manufactured anymore - what a shame. I've looked at immersion heaters and also stuffing a 50 gallon drum with elements from a stove. >> >> So far I like the electric water heaters the best. I can load to about 27kW and make up the rest with some big wirewounds I have kicking around. but looking for any alternate methods before I go to boss with the water heater idea. >> >> Any ideas? > > rent a load bank from a generator rental/testing company. > >
I like the idea of buying three water heaters and doing a little plumbing. Spend about $1200 and at the end of the job sell them for $250 and it only cost you $450. You might want to get 4 water heaters, reduce the amount of wire wounds heating the room. I would put a valve on the input of each so you can equalize the water flow, just to make sure one doesn't get starved. Mikek
On Mon, 07 Oct 2013 08:22:29 -0700, Yzordderrex wrote:

> I need to load up a 36kW 3 phase 240v (output) transformer to do a heat > run. I looked at having some inductors wound, but that was about $4k. > I've looked at custom load bank, also about $4k. I can run three > electric water heaters ($250.00 each)and discharge about 90 gals an hour > of hot water. The eagle glo-coils are not manufactured anymore - what a > shame. I've looked at immersion heaters and also stuffing a 50 gallon > drum with elements from a stove. > > So far I like the electric water heaters the best. I can load to about > 27kW and make up the rest with some big wirewounds I have kicking > around. but looking for any alternate methods before I go to boss with > the water heater idea. > > Any ideas?
This probably won't work because of asymmetrical cooling, and would only work if they have adjustable taps. But: You could hook up two, back to back, with taps set for different ratios. (or if you have an existing product, particularly bigger, use that). Verify that everything is phased correctly so that with the taps set at the _same_ ratio the outputs are the same (unless you like very large and spectacular career-changing events). The change the taps, and connect like outputs to like through small* resistors. Most of the 36kW (or whatever) flowing through the transformer will just get put back on the line, with only enough dissipated in the resistors to keep control of things, plus losses in the two transformers. * "Small" is a relative term when you're talking 36kW -- you'll need to do the math, but I suspect you'll be looking at no more than one or two kW each. If you can arrange your taps so that the difference between the outputs is 12V or 24V, then banks of automobile headlights would work, and would provide an easy way to switch load in and out. They'd also significantly reduce the drama if you do get the phasing wrong. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Yzordderrex <powersupplyguy@netzero.net> wrote:

> I need to load up a 36kW 3 phase 240v (output) transformer to do a heat > run. I looked at having some inductors wound, but that was about $4k. > I've looked at custom load bank, also about $4k. I can run three electric > water heaters ($250.00 each)and discharge about 90 gals an hour of hot > water. The eagle glo-coils are not manufactured anymore - what a shame. > I've looked at immersion heaters and also stuffing a 50 gallon drum with > elements from a stove. > > So far I like the electric water heaters the best. I can load to about > 27kW and make up the rest with some big wirewounds I have kicking around. > but looking for any alternate methods before I go to boss with the water > heater idea.
With the secondary O/C, measure the temperature rise due to iron losses with full primary volts and no secondary load Then short the secondary and apply reduced primary volts from another transformer to measure the temperature rise due to copper losses at full current. Then calculate the effect of both together. -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk
"Yzordderrex" <powersupplyguy@netzero.net> wrote in message 
news:ecd269f4-fe27-486f-91ca-9dbf88c4f492@googlegroups.com...
I need to load up a 36kW 3 phase 240v (output) transformer to do a heat run.  I looked at having 
some inductors wound, but that was about $4k.  I've looked at custom load bank, also about $4k.  I 
can run three electric water heaters ($250.00 each)and discharge about 90 gals an hour of hot water. 
The eagle glo-coils are not manufactured anymore - what a shame.  I've looked at immersion heaters 
and also stuffing a 50 gallon drum with elements from a stove.

So far I like the electric water heaters the best.  I can load to about 27kW and make up the rest 
with some big wirewounds I have kicking around. but looking for any alternate methods before I go to 
boss with the water heater idea.

Any ideas?

Bob

*********************
Clothes dryer elements are 240V and air cooled which may be
less work than plumbing the water heaters.  They're certainly less
expensive.
Art 


"Yzordderrex" <powersupplyguy@netzero.net> wrote in message 
news:ecd269f4-fe27-486f-91ca-9dbf88c4f492@googlegroups.com...
I need to load up a 36kW 3 phase 240v (output) transformer to do a heat run. 
I looked at having some inductors wound, but that was about $4k.  I've 
looked at custom load bank, also about $4k.  I can run three electric water 
heaters ($250.00 each)and discharge about 90 gals an hour of hot water.  The 
eagle glo-coils are not manufactured anymore - what a shame.  I've looked at 
immersion heaters and also stuffing a 50 gallon drum with elements from a 
stove.

So far I like the electric water heaters the best.  I can load to about 27kW 
and make up the rest with some big wirewounds I have kicking around. but 
looking for any alternate methods before I go to boss with the water heater 
idea.

Any ideas?

Bob
++++++++++++++++++++++++++++++++++++++++==

How about using one 55 gal drum (open) with several 4.5 kW water heater 
elements installed near the bottom. Just let it boil off the water and add 
more if necessary. You could wrap insulation around it for safety and pipe 
the steam outside.

tm 

On Mon, 7 Oct 2013 08:22:29 -0700 (PDT), Yzordderrex
<powersupplyguy@netzero.net> wrote:

>So far I like the electric water heaters the best. I can load to about 27kW and make up the rest with some big wirewounds I have kicking around. but looking for any alternate methods before I go to boss with the water heater idea.
I'm currently working on the PFC controller for our next generation induction heater. I load it at 20kW using stove eyes that I purchased from Amazon. Each one is worth about 1.5kW and cost (if memory doesn't fail me) less than $5. I have them suspended on a wire strung between two poles right outside my lab window. I hung them so the connectors were facing down to keep the heat off the Teflon insulated wire that I used. In free air like that and running just a little bit under-voltaged (two in series for a 400 VDC output), they get a dull red. Other than a salt water bath, this was the cheapest thing I could come up with. John John DeArmond http://www.neon-john.com http://www.fluxeon.com Tellico Plains, Occupied TN See website for email address
"Yzordderrex" <powersupplyguy@netzero.net> wrote in message 
news:ecd269f4-fe27-486f-91ca-9dbf88c4f492@googlegroups.com...
I need to load up a 36kW 3 phase 240v (output) transformer to do a heat run. 
I looked at having some inductors wound, but that was about $4k.  I've 
looked at custom load bank, also about $4k.  I can run three electric water 
heaters ($250.00 each)and discharge about 90 gals an hour of hot water.  The 
eagle glo-coils are not manufactured anymore - what a shame.  I've looked at 
immersion heaters and also stuffing a 50 gallon drum with elements from a 
stove.

So far I like the electric water heaters the best.  I can load to about 27kW 
and make up the rest with some big wirewounds I have kicking around. but 
looking for any alternate methods before I go to boss with the water heater 
idea.

Any ideas?

Bob

++++++++++++++++++++++++++++++++++++++


Another way would be to use a duct heater and fan assembly. I thing any HVAC 
supplier can supply what you need. I think they come in 15 kW steps.