Inside the Control Panel: Siemens Touch Screen, German Dual Thermocouples, Wiring by Voltage

Two questions come up in almost every enquiry we receive: “Will it work on my electricity?” and “Can I connect it to Artisan?” Both are answered inside one steel box on the side of the machine. This page opens it.

Where this step sits

Panel building and wiring follow burner assembly and come before the drive system is connected. Every panel is then checked in the electrical safety test.

Two probes, not one

A roaster with a single temperature probe tells you one number. That number is usually somewhere between the bean mass and the air around it, and it is different on every machine.

YS series roasters carry two German-made thermocouples: one in the bean mass (bean temperature, BT) and one in the drum air (environment or exhaust temperature, ET). DY series machines use a German-made bean probe with a digital display. With both, you can see the rate of rise, catch the turnaround, and tell whether a stall is coming from the beans or from the burner. On the automatic YS and SD Pro lines the control system tracks temperature to ±0.1 °C, which is the resolution you need if you want a profile to repeat rather than approximately repeat.

The probe in the photo is the bean thermocouple for an SD-3, before fitting. The tip sits in the bean mass at the position we have found gives the earliest, most stable reading for that drum.

Screen and controller

YS series and SD Pro series run on a Siemens control system with a Siemens touch screen. The screen shows the live BT and ET curves, burner and airflow settings, drum speed, and the elapsed time. Profiles can be stored and recalled; on industrial YS sizes the PLC also drives loading, charging, discharging and cooling in sequence. Our Siemens PLC automation article goes deeper.

DY series and manual SD models use a push-button panel with digital temperature displays — ignition, drum, cooling arm, cooling fan, exhaust fan — and a data logger port. Simpler, robust, and preferred by many roasters who profile by hand.

The photo of the curve on screen was taken during a factory test roast of a YS machine, not from a marketing render.

Wired for your voltage before it ships

Roasters are not “universal voltage” appliances. Motors, heating elements and the control transformer are selected for the supply they will run on. When you tell us your country, we wire the panel accordingly:

Our voltage guide covers single- versus three-phase and what to check on your site. Inside the cabinet, each circuit is protected by its own breaker, and the incoming supply terminal is labelled for your fitter. The breaker in the photograph is on a 220 V single-phase machine. Gas-heated machines ship with a plug for your destination; electric-heated machines ship without a plug (except the EC-500G) and must be connected through a residual-current device by your electrician. Thirty-four per cent of the orders in our records involved a voltage check before payment — send a photo of a nameplate in your building and we do it for you.

Connecting Artisan and other logging software

• DY series: USB and Bluetooth output for Artisan. Bluetooth pairing on some laptops needs the correct driver and port selection; our Artisan connection guide walks through it step by step, including the pairing issue a customer raised with a DY-3.
• YS / SD Pro: the Siemens system logs and stores curves itself; data can be exported, and USB data logging to a PC is supported.
• EC-500G: touch-screen panel with built-in data logger.

Tell us at order if you plan to run Artisan and we will confirm the connection method for your model before it ships.

What this means for you

• The machine connects to your supply and runs — no transformer, no rewiring, no “it was made for China”.
• You see what the beans are doing, not an average of beans and air.
• Curves are recorded on the machine or on your laptop, so a profile developed in week one is still there in year three.

How to verify this on any roaster

Ask for a photograph of the inside of the control cabinet on the model you want, and for the wiring diagram. You do not need to be an electrician to judge it: look for labelled terminals, separate breakers per circuit, tidy routing, and the voltage marked on the plate. A cabinet that looks like the one on this page is a cabinet your local electrician will be willing to work on.

Frequently asked questions

Do I need three-phase power?

Not for 1–15 kg gas machines, which run on single-phase 220–240 V. Electric-heated YS-6 / YS-12 need 380 V three-phase; 20–30 kg machines are built for 220 V or 380 V by order; 60 kg and larger need 380 V three-phase.

Can I run a 220 V machine on 110 V with a transformer?

For 110 V countries — the USA, Canada, Japan, Mexico — a correctly sized step-up transformer is the standard solution and we specify it with the quotation. Tell us your supply before ordering so the transformer rating matches the machine.

If the touch screen fails, can it be replaced separately?

Yes. The Siemens screen is a standard industrial part and can be replaced without replacing the PLC or rewiring the panel. See warranty and spare parts.

Why does the bean temperature reading differ from another brand at the same roast stage?

Because probe position, probe diameter and drum design differ between machines. Absolute numbers are not comparable across brands; the shape of the curve and the repeatability on your own machine are what matter.

Final thoughts

The control cabinet is where “works in China” becomes “works in your building”. We wire it for your supply, fit two probes so you see the roast, and use Siemens control on the automatic lines because it is serviceable anywhere. The key components page explains the parts we buy in; the YS series shows the machines this panel drives. Or return to the full build sequence.

Last updated: September 15, 2026