Skippedover was just kidding when he said to take a rest on top of the condenser. He knows axial Propeller fans can overload the blower motor when the discharge air is blocked. Just use something lightweight that the intake-side will hold against the condenser fins guards.
Squirrel cage wheels with forward curved blades on residential systems unload when discharge air is blocked off too much & will overload when there is no static pressure. There is a preferable ESP range for each AH blower design, that ought to be listed on the blower; they vary at the point of serious unloading. If you amp-probe check enough of those blower motors, if the amp draw is too low according to its rating, you can begin to tell that the ESP is too high.
I lot of us (bad boys) used to set a nearly empty R-22 cylinder on top of a condenser to warm it a little. Back then fan motors had more HP & higher amp draws, therefore it didn't seem to cause any harm, just more noise.
Back in the 1960's & 1970's there were a far number of TXV metering devices & some table top condensers' that had the fan underneath blowing up through the coils. Well, where there were cottonwood trees or a lot of leaves or other debris under the unit, the fan motors would overload & burnout.
I don't understand the engineering genius of that moronic design.
However, on hot days & a heat-loaded E-Coil, You could move your wrist over the condenser from outlet up to inlet, & tell if the liquid was taking up too much area of the coils; an overcharged system. - udarrell
Last edited by udarrell; 07-27-2008 at 08:41 AM.
Reason: Had a line in wrong order