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Registered Member #31557
Joined: Tue Aug 06 2013, 02:38AM
Location:
Posts: 58
Weighs 20lbs. Its intended for a Turbochef i5 10kw single phase commercial oven. Not sure what I'm going to do with it yet! For comparison, the one on the right is a 1800w 240v commercial MOT!
Registered Member #3324
Joined: Sun Oct 17 2010, 06:57PM
Location:
Posts: 1276
redruM69 wrote ...
From the oven's manual:
i5 US model (i5-9500-1)* 208/240 VAC, 60 Hz, 48 amps Max Input: 9500/11500 watts Plug: NEMA 6-50P
Yes but it's a simple case of physics. you simply can't put anywhere near that much power through that iron laminate core at 60Hz without it catching on fire.
The most it could mean is peak current.
I promise you that you will not get 10Kw though that core for any realistic length of time without it catching fire.
Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716
I'm not so skeptical. Maybe the 10 kW figure is input volt-amp product, unlike MO nominal wattages based on rate that the microwaves heat water.
MOT's are always underdesigned by traditional transformer rules, and _depend_ on intense forced air cooling.
Comparing the two MOT's in picture, if we assume the same current and magnetic densities, the volt-amp ratio should be similar to 4/3 power of the weight ratio. How much does the 1800W unit weigh?
Andy: Three-phase transformers have windings on three symmetrical legs of the core.
Registered Member #31557
Joined: Tue Aug 06 2013, 02:38AM
Location:
Posts: 58
klugesmith wrote ...
I'm not so skeptical. Maybe the 10 kW figure is input volt-amp product, unlike MO nominal wattages based on rate that the microwaves heat water. MOT's are always underdesigned by traditional transformer rules, and _depend_ on intense forced air cooling. Comparing the two MOT's in picture, if we assume the same current and magnetic densities, the volt-amp ratio should be similar to 4/3 power of the weight ratio. How much does the 1800W unit weigh?
Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716
OK, redruM.
I was about to ask if you wanted company, taking those doubters' words as a challenge. Looked up the specs for the oven model you named. To get fast cooking times, the i5 adds a microwave system to a resistance-heated convection oven
That power law formula suggests that the big MOT can handle around twice the power of smaller MOT. Weight ratio of 5/3 means the average linear dimension ratio is about 1.19. So core cross-section and winding-window areas could both be about 41% bigger. Same Bmax in the core would give 41% more volts/turn. Same amps/mm^2 in the winding would give 41% more ampere-turns.
Let's figure the rate that this thing would heat up from copper loss, at various currents. Could I bother you to measure the primary wire diameter and total DC resistance? The latter could be on the order of 0.1 ohm. Know how to do that? I think shorting the secondary would reduce the voltage spike when DC current source is disconnected. [edit] Now I'm guessing a whole ohm, if the microwave power is 3600 watts. To measure the DCR you can apply a DC current of between 0.1 and a few amperes, and measure the terminal voltage.
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