Product Overview

Pneumatic Control Manual 717.1
Temperature Section
Product Bulletin T-3610
Issue Date 0886
© 1986 Johnson Controls, Inc. 1
Part No. 24-4306-2, Rev. A
Code No. LIT-7171165
T-3610
Pneumatic Low Limit Thermostat
Features
•• Ball Type Control Port for
Increased Accuracy
•• New Lever with Reinforced
Edges for Increased
Linearity
•• Adjustable Sensitivity and
Set Point Dial
•• Integral Hypodermic Needle
Test Point
The T-3610 Pneumatic Low
Limit Thermostat is a low
volume controller designed to
maintain a minimum air
temperature. Pneumatic
feedback is incorporated into the
controller design to provide an
exact proportional relationship
between the measured
temperature and the control
pressure.
Models are available for unit
ventilator duct mounting
applications with an 8 ft
(244 cm) liquid filled averaging
element or an 18 in. (46 cm)
liquid filled rigid stem element.
Both elements provide air
temperature control with
minimum variation in response
to the average temperature
sensed by the element.
Operation
As the temperature at the
element increases or decreases,
the liquid in the element
expands or contracts and moves
a diaphragm in the controller.
This diaphragm movement is
transmitted through a system of
levers to open or close a control
port. The pressure increases or
decreases accordingly and the
feedback diaphragm along with
the element provides an
accurate linear response in
direct proportion to the sensed
temperature change.
Mounting
For unit ventilator applications,
the T-3610-1002 with 18 in.
(46 cm) rigid stem element is
furnished with a temperature
resistive plastic mounting
bracket. Mount the controller on
the panel adjacent to the
discharge air plenum inside the
end compartment. Insert the
rigid stem element through the
Specifications
Fig. 1: T-3610-1001 Pneumatic Low
Limit Thermostat