SE8350U5B11 Schneider SE8300 Room Controller PIR Motion Sensor White BACnet MSTP Five Relay Outputs

The SE8350U5B11 adds a PIR motion sensor to the SE8300 room controller, and the addition changes the control philosophy rather than just the sensor list. With occupancy sensing in the cover, the controller can decide for itself that a room has been empty for a configurable period and move to an unoccupied setpoint — without waiting for a telegram from a head end that may be offline.

The same hardware otherwise matches the rest of the family: 24 V AC supply, a 4 A line rating, five relay outputs at 1 A with 3 A inrush, four universal 0–10 V outputs, seven inputs split between dry contact and analog, BACnet MS/TP and Modbus RTU. The designation additionally marks it as ZigBee and IP ready for projects that intend to add a wireless or IP layer later.

Designing with local occupancy sensing means deciding what the sensor is allowed to do unsupervised. The useful pattern is a three-stage logic:

• Occupied — the occupant controls the setpoint.
• Standby — entered after a short delay, where the setpoint drifts a degree or two.
• Unoccupied — entered after a longer delay, where cooling and heating are suspended and only frost protection remains.

The PIR must be given a delay long enough to survive a guest sitting still to read — the failure mode that gives occupancy control a bad reputation — and the unoccupied stage should be short enough to matter on the bill. Because the sensor is in the controller rather than in the ceiling, its field of view is limited by whatever furniture is placed in front of it, so the mounting position relative to the bed or the desk belongs in the room layout rather than in the electrical schedule alone.

Occupancy sensing in the controller suits buildings that want the saving without a room-by-room sensor network:

• Budget hotels and serviced apartments — each room becomes autonomous: an empty room stops conditioning without any central decision.
• Student accommodation — rooms are empty for long periods and the energy bill is the landlord's.
• Small offices — specified in cellular rooms where the meeting schedule is unreliable.
• Residential apartments — used in second homes where the owner is absent for weeks.
• Clinics — used in consulting rooms that sit empty between appointments.