WT-4002-MFR Johnson Controls Thermostat

Overview

The Johnson Controls WT-4002-MFR is a wireless, two-pipe pneumatic-to-Direct Digital Control (DDC) room thermostat designed to modernize existing pneumatic HVAC systems. It acts as a non-invasive replacement for manual pneumatic thermostats, allowing for remote monitoring and setpoint management without the need for extensive rewiring. By utilizing a solid-state temperature sensor and a piezoelectric air valve, it eliminates the need for mechanical calibration and provides precise, maintenance-free control of pneumatic valves and actuators.

Features

• Wireless RF Communications: Provides real-time status and facilitates central automation via a building automation system (BAS).
• Advanced Piezoelectric Air Valve: Replaces traditional mechanical relays to improve branch line pressure control and eliminate mechanical wear.
• Stand-Alone Capability: Can be configured in the field for stand-alone operation if a network is not present.
• LCD Display: Offers an intuitive user interface with real-time indication of room temperature, setpoint, and branch line pressure.
• Energy Savings: Supports programmable temperature schedules and occupancy-based control to reduce energy consumption.
• Easy Installation: Designed for a non-invasive, no-wire setup that typically takes less than 30 minutes per unit.

Specifications

• Model: WT-4002-MFR
• Type: Two-pipe pneumatic
• Control Action: Direct Acting (DA) / Reverse Acting (RA) dual control
• Temperature Range: 32 to 99°F (0 to 37°C)
• Display: Fahrenheit (F)
• Power: Internal (four 3.6 VDC AA lithium batteries, 4-year life) or External (3.1 to 12 VDC)
• Air Connections: Dual barbed fittings for 5/32 in. or 1/4 in. O.D. polytubing
• Supply Pressure: 12 to 18 psig nominal; 30 psig maximum
• Wireless Band: 2.4 GHz ISM band (Direct-sequence, spread-spectrum)
• Material: White ABS plastic housing

Applications

The WT-4002-MFR is ideally suited for energy-saving building upgrades in commercial, industrial, and institutional environments such as schools, hospitals, and office buildings. It is specifically designed for facilities with existing pneumatic infrastructure that require the benefits of DDC, such as remote setpoint control, occupancy scheduling, and continuous zone monitoring, without the high cost of a full electronic retrofit.