Product Overview

www.usa.siemens.com/hvaccomponents
Thermostats
A-25
188 Unit Mounted Thermostat.
Applications
The 188 Unit Mounted Thermostats are designed primarily
for use in fan coil induction units and unit ventilators to
control the temperature within and occupied space. The
thermostats temperature range is limited to applications at
ambient temperatures.
Description
The 188 Unit Mounted Thermostat is a gradual acting
thermostat with a remote bulb operating on the force-
balance principle, using pneumatic feedback to obtain
linearity and maintain selected room temperature by
positioning pneumatic devices to control heating or
cooling.
Features
• Liquid-fi lled thermal system temperature
sensing element
• Durable die-cast metal case with rugged setpoint knob
• Adjustable sensitivity
• Universal mounting bracket for easy installation
• Integral adjustable limit stops
• Available as:
– Direct Acting only (Heating)
– Reverse Acting only (Cooling)
– Heat or Cool depending on supply air pressure
Typical Connections
188
Unit Mounted Thermostats