Taking an unusual "low road" here, I would not bother grounding the pstat. I have not seen ANY espresso machine pstat grounded with a wire connection to the chassis because the ground path already exists with the copper tubing.

Of course, in those instances where this pstat is connected to a pressure source with non-metallic tubing, then a ground connection is proper and hence the provision for same.

Very helpful. Thanks. That would have been like double wiring. I realized also that my metal bracket bolted into the frame acts as a ground too.

If it's already bolted to the frame, then you are fine. The ground would only be needed if the frame was composite or if the part mounted in such a way as to not provide a ground, etc.

However, just remember, if the frame is painted, the paint can inhibit the grounding effect.

Ray

Installing PSTAT and Vacuum Breaker, Troubleshooting

Today I learned more by doing some things wrong and having others work out. I installed the Sirai PSTAT and vacuum breaker plumbing well enough to test them and learn how to improve the installation. I also replaced the steam gauge that had started sticking with a stock one provided by Allann Brothers. A new stainless steel drip tray has come in that's deeper and wider and will replace the shallow one I had. But it required taking out the thin screw-on piece that held the stock drip tray. To get at everything, the case all fastened together now comes off in one piece by undoing the four screws in the front plate.



I fumbled with sweating the compression fittings onto the pipe and found they were coming off. The small torch wasn't hot enough, so I returned to a larger propane torch with a bigger flame. Then I made the mistake of soldering with the compression cap facing down, trying to fill the gap in the edge with solder. I filled the gap all right. It filled the end of the cap entirely!



This is how you learn, right? Well I'd learned earlier how to drill out stuck bolts. Solder is a whole lot softer. So not having any caps to spare, I drilled out this one with small Dremel bits mounted on a flexible extension shaft for the rotary tool. I began with a very small bit and worked my way up two more sizes. It came out fine and with later testing this compression fitting into the bottom of the Sirai PSTAT held. This is silver solder without heavy metals, so there's no health risk here.



Testing also showed me the fitting on the other end dripped. I removed the solder and sweated it again with the larger torch. It should hold this time. The same testing revealed that the vacuum breaker works but it creates a small fountain of hot water not unlike a Microcimbali with the High switch on. Although it wasn't that intense it was enough to jeopardize electrical connections, so I examined the end piece and realized it's a compression fitting that joins with the Teflon tube with end cap I'd sourced earlier. This will form the basis for a flexible tube that will route into the drip tray. I may eventually make it a permanent copper pipe but would need to source and solder the 4mm size for this fitting.



You may have noticed the position of the Sirai PSTAT toward the back of the frame. I was too clever for myself and tried to bend the pipe so it would simply wedge against that back frame. I learned that a wood block with a hole in it can be used for safely bending pipe.



And a Jorgensen clamp can take some of the bends out simply by tightening down.



But I'm now putting Rustoleum on the angle bracket that will support the front of the PSTAT. It will prop up the front and I'll use cable ties to support it. The pipe on the bottom and the PSTAT wedged against the frame was still too wobbly.

I also learned how to wire the PSTAT through trial and error. Each of these pairs of terminals hooks to an incoming and outgoing hot lead. Now I understood these vertically aligned screws in the photo were both ends of three separate normally closed (NC) circuits that open when the machine comes up to pressure to power off the heating element.



I received ceramic wool plumbing from McMaster-Carr and was browsing the site to see how people cut it. Then I saw there are health warnings for this stuff. If fibers come loose they can be inhaled and some government agencies consider this a potential cancer risk. I'll probably go with Melamine instead, as suggested in this old thread.

More on boiler insulation

Tomorrow I'll contact McMaster-Carr to ask about the actual product they sent me at high shipping cost and without a health warning posted on their site. Added: I talked to someone there who was very helpful and is crediting the product and shipping cost. They'll send me replacement Melamine insulation and some cable ties today. Also they'll update the ceramic insulation listing to include health warnings.

A note on Melamine: I have worked with it and when cutting, it makes some dust. It smells funny and the dust bothered my sinuses. I am sensitive to dust and the like, so it may have just irritated my sinuses, but to be on the safe side, I recommend wearing at least a basic particulate mask and doing the cutting in the garage or outside.

Thanks, jonny:

Each material's a new experience on one long learning curve of a project.

drgary wrote:...
I fumbled with sweating the compression fittings onto the pipe and found they were coming off...

I'm not sure exactly which kind of compression fitting you are using. But, if they are bicone fittings, like these at orphan, they do not need to be soldered.

If you look closely at the second photo above, you'll notice that they are indeed solder-on cap fittings like these: http://orphanespresso.com/Solder-on-Cap ... _3200.html

drgary wrote:Thanks, jonny:

Each material's a new experience on one long learning curve of a project.

You always have to be very careful when working with different materials. I remember a story I heard at the boat yard (when working on my boat in drydock). This guy has sanded the inside of his boat hull, which was fiberglass, and failed to use a mask. He got fiberglass in his lungs and the doctors couldn't do anything to help him. They said he ended up committing suicide a while later.

So be careful and always use a high quality respirator and always eye protection.

Another story (speaking of eye protection). My buddy was working with his friend on their home. The guy was using a screw driver to pry up some nails or something; the screw driver slipped and went right into his eye. It ruptured his eye ball and he lost his eye.

I, myself - when I was younger, sprayed a car with some very toxic paint and was using the wrong type of respirator. I ended up 1/2 way passed out on the floor of the garage. Suddenly I realized I was on the ground, instead of standing over the car.

After that I had a difficult time getting a full breath of air for a number of years. I went to the doctor and they said I had basically given myself mild emphysema (or something along those lines). I don't think things went back 100% to normal for maybe 7 or 8 years.

So be careful out there.

Ray

Thank you, all. When installing the Melamine insulation I'll look up any precautions and will take them. I do have a breathing mask for installing that and when doing metal work, leather welding gloves and full face protection.

And I am using solder on fittings because bicone fittings aren't held in place by the compression caps that fit the other plumbing fixtures. The challenge now is to finesse exactly where the Sirai PSTAT will sit, how it will be supported, and bending pipe so it connects on both ends.