Finnleo CB16-3 Contactor Box (3-phase)

Finnleo CB16-3 Contactor Box (3-Phase)

What the CB16-3 Does

The Finnleo CB16-3 Contactor Box is the high-voltage relay component that bridges your low-voltage SaunaLogic2® control and the full line-voltage power draw of your sauna heater. The SaunaLogic2 touchscreen or panel is not rated to carry heater-level current directly; instead, it sends a low-voltage signal to the CB16-3, which then switches the true 240V three-phase (or 208V three-phase, commercial applications) power on and off to the heating elements. Without a correctly matched contactor box, a SaunaLogic2 control cannot safely or legally operate a heater. The CB16-3 is the three-phase counterpart to the CB16-1 (single-phase) unit, purpose-built for installations where three-phase electrical service is being run to the sauna heater.

Heater and Electrical System Compatibility

The CB16-3 is engineered specifically for three-phase 240V (or 208V, in commercial settings) service and is paired with Designer SL2 series and Himalaya series sauna heaters operating on three-phase circuits. As with the entire CB16 family, correct sizing depends on both the amperage draw of the heater and the phase configuration of the electrical service feeding it — three-phase heaters require the CB16-3, while single-phase heaters of the same wattage require the CB16-1 instead. Selecting the wrong contactor box for your heater's phase configuration will prevent proper operation and can create a safety hazard, so confirming your heater model and electrical service type before ordering is essential. If you are unsure whether your installation calls for single-phase or three-phase service, check your heater's nameplate rating or send us the heater model and we'll confirm the correct match.

Construction & Installation

The CB16-3 is housed in a rugged metal enclosure measuring approximately 11-3/8"W x 8-1/2"H x 3-1/2"D (dimensions vary slightly by production run), sized to mount conveniently on or near the sauna room wall, either inside or immediately outside the sauna enclosure per code and manufacturer guidance. Internally, the unit houses heavy-duty contactor relays rated for continuous sauna-heater duty cycles and repeated on/off switching without degradation. The enclosure provides clearly labeled terminal connections for three points: incoming three-phase line power from your electrical panel, the low-voltage control signal wiring from the SaunaLogic2 control, and the outgoing power leads to the heater itself. The unit carries UL/NRTL listing and is rated for a maximum ambient temperature of 194°F, allowing safe installation in proximity to sauna heat. Installation should be performed by a licensed electrician in accordance with local electrical code, the National Electrical Code (NEC), and the specific wiring diagrams provided in the Finnleo installation manual for your heater and control combination.

Why It Matters

Every feature that makes SaunaLogic2® feel effortless — instant start from the touchscreen, scheduled sessions, Wi-Fi app control from across town — depends on a correctly sized contactor box working invisibly behind the wall. The CB16-3 is what allows a delicate low-voltage touchscreen signal to safely command a heater drawing significant three-phase current, without ever putting mains voltage anywhere near the control interface or the person using it. It's a small, unglamorous component, but it's the piece of hardware that makes the entire SaunaLogic2 ecosystem possible on three-phase installations.

Why Choose Finnleo

Finnleo, built by Sauna360 in Cokato, Minnesota, is one of the most trusted names in authentic Finnish sauna. Every component in the SaunaLogic2® ecosystem — heater, control, and contactor box — is engineered, tested, and listed as a matched system for the North American market. As an authorized Finnleo dealer, we offer full factory warranty support, expert help matching your contactor box to your exact heater and electrical service, and guidance before and after your purchase. Not sure if you need the CB16-1 or CB16-3? Send us your heater model and electrical service details and we'll confirm the exact match before you order.