t3chiman Senior Member Joined: 26 Dec 2011 Posts: 15 Location: Chicago Expertise: I love coffee
Espresso: Cuadra Grinder: hand Drip: Brazen
Posted Sun Jun 23, 2013, 11:30am Subject: Adding SSR to Cuadra, notes and experiences Sec 1/7
Foreword Over a year ago, the coffeegeek community put me on to the benefits, and value, of the Cuadra espresso machine. In that time, I have come to admire the ethical business practices of 1st-line. With such positives in mind, I offer some payback, in the form of a photoessay on my experiences in swapping out the stock electromechanical relay for a solid state functional equivalent. This is not intended to be a definitive statement on the topic; more of an anecdotal description of my thoughts and experiences as I solve a particular appliance malfunction problem. And it is far from my best work in electronics engineering. On the other hand, it does work. And that's something. I offer it in gratitude to the community, and in the hope that it will inspire others to offer other, ever more improved, solutions to the problem.
Disclaimer Up front, it goes without saying, but I gotta say it: opening up a box with 120VAC, lots of wires, connectors, 1200W heaters, etc., inside brings its own set of hazards into your life. Keep aware, at all times, of the status of the power connection (Off and unplugged 98% of the time). Have a clean, well-lighted place to work. Know what you are doing in the areas of appliance wiring and metalbending. Document your work. And, finally, understand that, as with any mod to somebody else's product, the ongoing support policy is YOYO (You're On Your Own).
It doesn't heat up It's distressing. After a year or so of reliable operation, Cuadra heats only partially, intermittently, or not at all. After verifying the obvious, you turn to Google, thence to coffeegeek. "It's the relay". After popping off the top and left-hand (from the front) side panels, you spot it: a 1x2 inch circuit board, with a medium sized electromechanical relay mounted on it. Even without shining a light on it, you can see that the contact enclosure is obscured with soot. You may reason: "Aha, the contacts are dirty. I will clean them, and all will be well." And it's true enough. A good cleaning will restore normal operation. For a day or so, in my experience. The trouble is that the contacts have been switching 10A AC, and they are not meant to do this for more than 100,000 times (25000 is what Omron has verified). Cuadra's heater control logic (the p-stat) activates the heater every 35 seconds or so after initial warmup. Do the math. Figuring 100 operations per hour, after 250 hours of operation, you can expect to have relay-related performance problems with your Cuadra. After 1000 hours, you will.
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