[Amps] Bird water load ratings

[John T. M. Lyles]

I have attempted to run 1 kW Bird water loads at higher peaks, in a 
pulsed amplifier for work.  Talking to the Bird people convinced me 
that it was not a good idea, that thin film on ceramic resistors that 
they (and Altronics in Arkansas) use cannot take much peak voltage. 
However, I believe that you are talking more about just overdrive, 
for short periods. I would not recommend it with these loads if they 
have any value to you (if you paid much for them). You could run with 
a higher Delta Temperature in your water lines, but then you start 
running the risk of boiling on the surface of the resistor. If there 
is imperfect laminar flow inside the element, with some voids that 
may not be transferring heat to the water, you risk localize hot 
spots and boiling.

Better to find a bigger load, or make one. BTW, what are you doing, 
cooking some big bacon there?

73
John
K5PRO




>I am in need of some info regarding the Bird 8230 dummy load.
>
>It is rated at 2.5kW continuous duty (with water flowing).  Is it rated for
>any intermittent-duty ratings?  (i.e.  For operation at power levels above
>2.5 kW at less than continuous-duty?)  If so, any reference to the
>intermittent-duty ratings would be most-appreciated.
>
>Thanks for the information,
>
>Cliff
>NC4CB
>Winston-Salem, NC