Interesting. My machine is on a very low use circuit but it is at the end of the loop, about 38 feet from the breaker box, 20 amps I believe. I will have to check the power cord gauge next time I crack the case.another_jim wrote:You can get relief in two ways:
1. Finding an outlet close to the circuit breaker panel (not always possible). If you are really incensed by this, run a 12 gauge extension cord to a close outlet.
2. Replacing the existing 18 (!) gauge power cord of the machine with a 12 gauge cord (the wiring on Italian machines is never changed compared to the 220 models -- a very bad practice, albeit within code, since they spec very fine wire gauges for "within panel" wiring). This fix got me from 1/2 bar down to about 1/6th bar change during heating cycles.
I believe pressure stability/adjustability will be the next target of the market. PID's have really tightened down thermal stability, but if you cannot control the pressure, your returns are limited. Some days I can pull incredible shots using my lever machine, part pressure control, part luck (Probably more luck than skill) .
Jim would be better than I at explaining, he is the process controls master. Regardless of how much pressure your pump can generate, it requires X watts to operate at that level. If I am supplying a pump with X watts, then suddenly turn on a hair dryer in the circuit in front of the pump, that device will pull Y watts out of the circuit. So if my 500 watt pump (just grabbing a number out of the air) pumps at 9 bar at 500 watts, but I drain off 250 watts of power on that circuit, my pump now only has 250 watts to work with, so it slows down. Now my 9 bar pump can only muster 4.5 bar.s_m_k wrote:I don't doubt that you've seen this, but it doesn't make sense to me. I thought that pumps typically operate well above the required pressure (15 bar or so) and the OPV regulated down to the "working" pressure.
Is this a false assumption? After all, I am a newbie.
My new machine (check out the Faema rebuild thread) is a rotary pump 220. The machine only draws 13 amps, has a 20 amp rated power cord, and I am supplying that with a 30 amp circuit (10/3 wire), so power should not be a problem any longer.
And the answer is....sunnyu wrote:cannon,
Would be most interested to read the results. Thanks.
From a cold machine (no heat induced line pressure) with no portafilter I fill a Pyrex one cup measuring cup in 29 seconds. Keep in mind that the heating element is on while the machine pumps, so it may be a second quicker with that off. But that should be close enough for government work.