La Scalla Butterfly Switch Keeps Failing - Page 6

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
daviddecristoforo (original poster)

#51: Post by daviddecristoforo (original poster) »

Ok. But it's not the box in my machine which was purchased in the US and has a120v box as you can see in the pictures I posted.

Alan Frew

#52: Post by Alan Frew »

Check the serial number, 9.9.04 . Your box (apart from being 110v) is identical, and the wiring mapping should be the same. Turn the photo upside down and you'll see it. The SL pins are for water level, the Min or Serb for the tank, the Max or Cald for the boiler. Plumbing in your machine means that the Min/Serb pin must be connected to Earth, otherwise the box detects low water in the nonexistant tank, turns on the light and shuts down the machine.

Except, if you look at the top of the box you'll see a hole (may be covered in tape.) Inside this hole are 2 brass pins, on the plumbed in Eroica they are connected by a jumper. When the jumper is in place and the wiring is "factory Butterfly" the green light never comes on, because the "low water" condition isn't detected regardless of tank water level.

Ditto if the Min/Serb pin is connected to Earth. If the jumper is removed and the Min/Serb pin isn't connected to Earth, the light will come on.

You might want to check that the rest of the colour coded wiring is correctly connected while you are at it.


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daviddecristoforo (original poster)

#53: Post by daviddecristoforo (original poster) »

I see what you are saying. The pins are identical but labeled differently. The light has come on briefly at times but the machine never shut down. I'll look at it again tomorrow and see if I can find the jumper.

daviddecristoforo (original poster)

#54: Post by daviddecristoforo (original poster) »

So I looked over the box and I don't find any indication of a jumper, just the large silver color labels that cover most of both sides. Would you be able to be more specific about it's location? And if there's no jumper, should I connect the pin labeled "SlivSerb" to ground (earth)?

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#55: Post by ira »

If the boiler fills properly and you're not getting an error, it's unlikely you need to do anything. Without a reason to make more changes, I'd say, leave it alone. It's apparently the controller for an ECM Giotto but I failed at finding a wiring diagram for that.


daviddecristoforo (original poster)

#56: Post by daviddecristoforo (original poster) »

I'm with you. I pretty much came to the same conclusion. I'm just going to cap the unneeded wires and call it good. I'm going to bring the machine back online this weekend and I'll run it for a week or so and see if I have any more issues. Hopefully I've got it fixed and if the switch doesn't melt within a week, I'll button it back up and call it done.

daviddecristoforo (original poster)

#57: Post by daviddecristoforo (original poster) »

I got everything put back together and hooked the machine up today. All seems to be working properly. But that was always the case before after installing a new switch. This time, I'm leaving the case off until I'm sure it's not going to melt down again. After being on and used for several hours, I checked the temperature of the switch body and contacts. the highest reading I could get was 109 degrees. That doesn't seem to be enough to cause a problem. Theres nothing within range of the boiler that measures lower than that. If the switch was overloaded, it seems like it would get hotter within a period of several hours. So maybe I've solved the problem. I'll use the machine for a week or so and if it's still OK, I'll button it back up.

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#58: Post by ira »

Glad to hear it seems better.


daviddecristoforo (original poster)

#59: Post by daviddecristoforo (original poster) »

She Lives!

It's been a full week now and there have been no issues. The switch is staying "cool" now (Temperature checked every day after the machine has been on for several hours.)

The machine now has a new pump, a new pstat, all new valves and a new control box. Modifications include the rotary pump, new switch and "Power On" indicator, Quickmill joystick type steam and hot water valves, Coffee Sensor flow control installed in a completely rebuilt E61, gauges from Lelit and a shot timer. Portafilter from ECM. Feet are repurposed wall sign standoffs.

In it's prior life, the machine had a drain tube connected to the expansion valve that was plummed into my sink drain. That was a bit cumbersome so I drilled one more hole in the front panel and installed a fitting so that the overflow now drains into the drip tray which was never plumbed in to begin with.

I should note that during the "rebuild" I was using a machine with a stock vibrational pump and water tank. I really didn't notice any real difference in performance or sound level. The pumps sound different but they seem to work well either way. But with the plumed rotary pump I don't have to worry about forgetting to refill the tank!

Today I felt confident enough to feel like it was not an act of folly to put the case back on the machine. Here's some pics of the machine.

The spring seen in the last pic was added to resist the torquing action when the pump motor starts. The pump is mounted on rubber isolation mounts but there are only two so the motor tends to rock slightly. The spring fixes that nicely.

It's been a somewhat long and frustrating path to get the machine to this point but it should be good for a long time now. I don't think I would have made it this far without the help received from the members of this forum and I want to express my gratitude for this.