Isomac Tea Due and Millennium: Replacing the Old Control Board with NEW GICAR NRL30 — Full Wiring Guide
The original Protel PRAL3A control board fitted to the Isomac Tea Due and Millennium is no longer available new. The correct modern replacement is the GICAR NRL30/1E-2C/F (Isomac part IS000601). The two boards use different connector layouts — the Protel uses a 10-pin connector, the GICAR uses a 7-pin connector — but the wiring mapping is straightforward once you understand which terminals correspond to which functions.
This guide gives you the complete pin-by-pin wiring map based on the official diagram, so you can make the swap confidently.
⚠️ Safety First
Always unplug the machine from the wall before opening it or touching any wiring. Photograph all existing wiring before disconnecting anything. Espresso machine wiring carries 230V mains voltage — incorrect connections are dangerous.
The Two Boards
| Detail | Old Board | New Board |
|---|---|---|
| Manufacturer | Protel Ind. | GICAR |
| Model | PRAL3A | NRL30/1E-2C/F |
| Code | — | 9.1.4.71G |
| Connector | 10-pin | 7-pin |
| Isomac Part No. | — | IS000601 |
| Voltage | 230V | 230V |
Wiring Diagram
The diagram below shows the official pin mapping between the old Protel PRAL3A and the new GICAR NRL30/1E-2C/F board.
Step-by-Step Replacement Procedure
- Unplug the machine from the wall and allow it to cool completely.
- Remove the top panel to access the control board.
- Photograph the existing wiring on the Protel board from multiple angles before touching anything.
- Label each wire with tape and a marker if needed — especially the white wires which appear on multiple pins.
- Disconnect the Protel board harness and remove the board from its mounting.
- Mount the new GICAR NRL30 board in the same location.
- Connect each wire to the correct GICAR terminal using the pin mapping table above. Work through the table one row at a time.
- Double-check every connection against the diagram before powering on. Pay particular attention to the F (live), GND (earth), and COMUNE N (neutral) terminals.
- Reassemble the panel and refill the water tank.
-
Power on and test:
- Machine heats up to operating temperature ✔
- Water level sensor triggers correctly ✔
- Pump activates when brew switch is pressed ✔
- Fill solenoid operates correctly ✔
🛒 Shop Isomac GICAR Control Board
Frequently Asked Questions
Does this wiring guide apply to both the Tea Due and Millennium?
Yes — both models use the same Protel PRAL3A board and the same GICAR NRL30/1E-2C/F replacement. The wiring map in this guide applies to both machines.
The wire colours on my machine don't match exactly — what should I do?
Wire colours can vary slightly between production runs. Always cross-reference with the function label on the Protel board terminal (POMPA, EV. CARICO, RESISTENZA, etc.) rather than relying on colour alone. If you're unsure, contact our service team before connecting.
My machine still doesn't work after the board swap — what should I check?
First, recheck every connection against the wiring table. The most common issues after a board swap are: a wire not fully seated in its terminal, the water level probe not connected, or the live/neutral reversed. If all connections are correct and the machine still doesn't work, the fault may be in another component (element, pump, solenoid). Contact us for further diagnosis.
Can I use this board on other Isomac models?
The GICAR NRL30/1E-2C/F (IS000601) is specifically mapped for the Tea Due and Millennium. Other Isomac models may use a different board variant. Contact us with your model name to confirm compatibility.
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