RAB20 Series
Technical Instructions
Document No. 155-526P25
ET RAB-2
March 2, 2007
Two-pipe Fan Coil Room
Thermostat with Automatic
Changeover
RAB20.1
Description
Two-wire, gas diaphragm-based fan coil room thermostat for heating or cooling
systems with two-pipe fan coil applications.
Features
•
•
•
•
•
•
•
•
Automatic
changeover
Manual, three-speed fan switch
Fan release function
Dual setpoint temperature scale
Two-point control algorithm (On/Off)
24 to120 Vac, 277 Vac operating voltage
Two mounting styles: electrical wall box or drywall
Wall plate adapter (ARG70) included with electrical wall box mount styles
Application
The RAB20… is used in heating or cooling systems with external automatic
changeover devices (aquastats) to maintain the selected room temperature.
Typically used in commercial, high-rise and light industrial buildings in conjunction with:
•
•
•
Fans
•
Zone
valves
Thermal
valves
Aqua sensors (changeover sensors, provided by others)
Product Numbers
See Table 1.
Accessory
ARG70 Wall box adapter
Technical Design
The RAB20… fan coil room thermostat is based on a two-wire, gas diaphragm
technology.
Siemens Building Technologies, Inc.
