Download A19AAH Type Mixed Air Thermostat Low Voltage

Installation Sheets Manual
Temperature Controls Section
Technical Bulletin
Issue Date
121
A19AAH
0479
A19AAH Type Mixed Air Thermostat
Low Voltage - Narrow Differential
Application
The Type A19AAH is designed
for use as a mixed air thermostat
in the output circuit of a
Cybertronic controller. It has a
7-1/2 ft liquid filled averaging
element with an operating range
of 40 to 120°F (4 to 49°C). The
element responds to the average
temperature along its entire
length.
This two-position thermostat has
a sealed, dust-tight, SPST switch
that opens on a temperature
decrease. The A19AAH has a
fixed differential of 3/4°F and a
visible dial with a screwdriver set
point adjustment.
The A19AAH may be mounted in
any convenient position on a flat
surface using the four mounting
holes in the back of the case.
When mounting on a very rough
surface use only the top two
mounting holes.
Wiring
! CAUTION: Disconnect
power supply before wiring
connections are made to
prevent possible electrical
shock or damage to
equipment.
All wiring should conform to
diagrams furnished with the
instrument, the National
Electrical Code or local
regulations.
! CAUTION: Use No. 8-32 ×
1/4 in. terminal screws.
Longer terminal screws can
damage the switch.
Adjustment
A screwdriver set point
adjustment is provided with a
dial indicator located on the
cover. The low cutout stop is an
integral part of the thermostat
and can be adjusted by the
sliding stop. To set the low
cutout stop:
1.
Set the dial to the
temperature desired.
2.
Remove the cover.
3.
Slide the dial stop to the
front of thermostat (toward
dial) against the step
located behind the dial, see
Fig. 2.
Note:
Type A19AAH Thermostat.
An exact stop setting
may not be possible.
Set the stop to the
closest step
corresponding to the
desired setting.
Specifications
© 1979 Johnson Controls, Inc.
Code No. LIT-121025
Part No. 997-750
1
Controls Group
507 E. Michigan Street
P.O. Box 423
Milwaukee, WI 53202
2 A19AAH Technical Bulletin
Printed in U.S.A.