Breville Dual Boiler "Slayer shots"? - Page 26

#251: Post by **Jake_G** » January 28th, 2019, 5:57 pm

Can you post a picture of your wiring scheme?

January 28th, 2019, 6:45 pm

Here:

On EDIT: This picture is of the steam boiler fill pump. It lies to the right of the brew pump. The wiring I added for the switch has blue crimp terminals, and it is displayed in this photo on the steam boiler pump, so you can see what needs to be done on the main brew pump. In other words, you want to replicate what you see here, BUT on the pump to the left of this one, which is the main brew pump. The terminals on the main brew pump are partially blocked by a bracket, so they wouldn't show well in a photo. In un modified form, the terminal with the black insulation goes on the pump terminal where you see a blue insulator.

-Peter

#253: Post by **Jake_G** » January 28th, 2019, 6:52 pm

pcrussell50 wrote:Here:
<image>

Normally the red wire with the black heat shrink goes on the middle blade of the pump. I pulled it, and put a long red wire with blue crimp on blade connectors in line with the original harness, so the current now runs from the stock black connector, through the wire I spliced in, to the blade on the pump. Next, I cut the wire I added and spliced in an on/off toggle switch. When the switch is open, whatever current/signal is trying to go from the stock harness to the pump, is stopped by the open switch. Only, when I open the switch, with the pump running, the pump keeps running.

-Peter

Can you start a shot with the switch open?

January 28th, 2019, 6:58 pm

Nevermind the struck text

GOOD question

I'll let you know in a couple of hours. Gotta take my little girl to her kung fu class.

-Peter

January 28th, 2019, 9:51 pm

Jake_G wrote:Can you start a shot with the switch open?

Nevermind the struck text

Yep. Pump comes on like a champ, not only with the switch open, but with the switch removed entirely and the ends dangling free.

Barring any other suggestions, tomorrow I will get another switch and splice it in to the other (white) lead so I can try it with both leads open.

I am stretching beyond my qualification to speculate here, but I wonder if one lead provides half of the signal, and the other lead, the rest of it or the trimming portion of it, so that the pump will still run with either, but maybe not run "right"... Thus, shutting off both, with will (should) shut off the pump.

-Peter

#256: Post by **Jake_G** » January 28th, 2019, 9:59 pm

pcrussell50 wrote:Yep. Pump comes on like a champ, not only with the switch open, but with the switch removed entirely and the ends dangling free.

Barring any other suggestions, tomorrow I will get another switch and splice it in to the other (white) lead so I can try it with both leads open.

I am stretching beyond my qualification to speculate here, but I wonder if one lead provides half of the signal, and the other lead, the rest of it or the trimming portion of it, so that the pump will still run with either, but maybe not run "right"... Thus, shutting off both, with will (should) shut off the pump.

-Peter

It should not run with only one wire connected...

This is beyond weird. Regardless of whatever voodoo tricks they are using to control the pump, voltage in and of itself is useless without a reference. This is why so many machines can get away with switching the neutral and leaving the hot well, hot. Without a neutral reference, no voltage can be measured and no current can flow. Something else is going on here...

You're positive you're on the brew pump and not the steam boiler pump, right?

January 28th, 2019, 11:13 pm

Jake_G wrote:You're positive you're on the brew pump and not the steam boiler pump, right?

Somebody was bound to ask that. Might as well have been you. And the answer is that it would be even weirder if it was the steam boiler pump... because the pump I have been working on is the one with the brass neck that I installed myself, and put a brass opv on. And the tube coming out of it goes to the heat exchanger in the steam boiler. And when I adjust the opv attached to it, the gauge responds accordingly.

I'm as mystified as anyone here. Weirdness.

ETA: My idiocy knows no bounds. It was the steam boiler pump. Doh! x1000. I will fix this tomorrow morning and have a soaked and bloomed shot for my first in the morning.

-Peter

#258: Post by **Jake_G** » January 28th, 2019, 11:50 pm

I knew full well you knew which pump you were working on given your intimate familiarity with the machine, but yeah. Couldn't resist the jab

Glad I could help

January 29th, 2019, 10:48 am

Success! EDIT:Breville Dual Boiler "Slayer shots"?, which is also edited now, where this idea got started.

Sipping a shot that was bloomed in the silence of a shut off pump. Of course you can still hear the hum of the energized solenoid, as in Jake's recent videos in the "long and rambling path" thread.

-Peter

#260: Post by **mrjag** » January 31st, 2019, 3:04 pm

No rush, but would you mind taking a pic of the rewiring next time you have the top open? I'd like to adopt this mod but I'm clueless about the wiring and would hate to fry something with guesswork.