Joint hogger, on Jan 14 2011, 02:30 AM, said:
troy, on Jan 13 2011, 05:21 PM, said:
Thanks bluecheese. Sorry to be a bit thick, is one variac for the extraction and the other for the intake ? Can you have one variac for the tick over for both fans and another variac to set the speed for when the thermo kicks in ? I've got the kit but baffled at the moment.
eta Just looked again and it seems that you have separate variacs for each fan and then a relay which switches both fans to full when the thermostat kicks in , is that right ?
exactly like that
at the moment tho, i changed one of the 0.75 variacs for a 1A variac, it was running hot when set to 40-50% so i upgraded
the new variac works a treat with my 6" hp ruck, got it set to 45% just now & the temps are a stable 76f.
on another thread Davey Jones recommended not setting a variac below 66%, i'lll need to ask him & find out why ?
really?? it was probably me, and saying 30%
at 30% the fan is moving pretty slowly, and it's the minimum voltage rvk recommends there fans to be run at, at a 100v, a fan is producing around 2 pascals of pressure
so not worth going any lower anyway. when you reduce the voltage to a fan, as well as slowing the fan, the fan heats up, the fan uses the air flowing over it too self cool it, if you slow it so much that airflow is virtually non existent, then this is bad for your fan (and of course, why run a fan at all, if it's so slow it's barely moving any air )