Johnson Controls A19 Series temperature controls are designed to cover a
broad range of uses for heating and general purpose
requirements. Controls
have SPST contacts which open on temperature
increase or they may be supplied in single-pole,
double-throw contact action.
Various control ranges are available to cover working
temperatures from -30 to 550° F (-34 to 288° C).
Closed tank fittings and bulb wells are available for
immersion applications.
These controls are designed for open low and open
high applications. Where critical or high value
products are to be maintained within a specific
temperature differential, a single control should not
be applied to function as both an open low and open
high control. In these applications, a separate backup
control with alarm contacts should be wired to
indicate when the back-up control operates.