Johnson Controls Thermostat A19A - Manual (Page 2)

A19A
Issue 03/03/2003
Catalogue Section 1 © 2003 Johnson Controls Inc.
Order No. PD-A19A-E
2
N
ote
These controls are designed for use only
as operating controls. Where an operating
control failure would result in personal injury
or loss of property it is the responsibility of
the installer to add devices or systems that
protect against, or warn of, control failure.
SPDT contacts are standard on all models.
Instruments have compact sizes. Types
A19ACC and A19ADC have a trip-free manual
reset . Reset button must be pressed and
released. Contact cannot be blocked in closed
position. All types have VDE and SEV approval.
To facilitate ordering, wholesaler codes have
been added on some universal models.
All models are provided with a separate knob
and sealing cap.
T
ype number matrix
A19AAC capillary thermostat, fixed differential.
A19AAF capillary thermostat, special close
fixed differential.
A19ABC capillary or immersion thermostat,
adjustable differential.
A19ACC capillary thermostat, lock-out low
with manual reset.
A19ADC immersion thermostat, lock-out high
with manual reset.
A19BAC space thermostat, fixed differential.
A19BBC space thermostat, adjustable
differential.
A19DAC strap-on thermostat.
A19DAF strap-on thermostat
A
djustment
1. Models “set low” (refer to cover label)
The dial indicates the low switch point
(1 - 2 open, 1 - 3 closed).
The high switch point (1 - 2 closed,
1 - 3 open) is obtained by adding the
differential to the low switch point.
2. Models “set high” (refer to cover label)
The dial indicates the high switch point
(1 - 2 closed, 1 - 3 open). The low switch
point (1 - 2 open, 1 - 3 closed) is obtained by
deducting the differential from the high switch
point.
Exception: Type A19ADC, dial indicates high
switch point ( 1 - 3 closed, 1 - 2 open).
N
ote
The standard screwdriver adjustment can
be converted easily in the field to knob
adjustment. Also concealing of adjustment
and scale is possible after installation.
C
ontact functions
Types A19AAC,
A19AAF, A19ABC,
A19BAC, A19BBC,
A19DAC
Fig. 1
1-2 closes on temperature increase
Type A19ACC
Fig. 2
1-2 opens on temperature decrease
Type A19ADC
Fig.3
1-2 opens on temperature increase
R
epair and replacement
Repair is not possible. In case of an improperly
functioning control, please check with your
nearest supplier. When contacting the supplier
for a replacement you should state the
type/model number of the control. This number
can be found on the data plate or cover label.
1
2 3
θ >
1
2 3
θ <
1
2 3
θ >