Penn A19BAC User manual

Installation Instructions A19BAC, A28AA
Issue Date September 2018
© 2018 Johnson Controls 1
Part No. 996-238, Rev. F
A19BAC, A28AA Single and Two-Stage Space Thermostats
for Farm and General Purpose Applications
Application
The single-stage A19BAC and the
two-stage A28AA thermostats
incorporate single-pole double-
throw (SPDT) switches for
controlling automatic ventilation or
heating in livestock barns, poultry
houses, milk houses, brooder
houses and other buildings. The 30
to 110F (0 to 43C) and 0 to 140F
(-15 to 60C) temperature ranges
permit use for many space
applications.
IMPORTANT: The single stage A19
and A28 thermostat is intended to
provide an input to equipment
under normal operating conditions.
Where failure or malfunction of the
thermostat could lead to personal
injury or property damage to the
controlled equipment or other
property, additional precautions
must be designed into the control
system. Incorporate and maintain
other devices, such as supervisory
or alarm systems or safety or limit
controls, intended to warn of or
protect against failure or
malfunction of the thermostat.
IMPORTANT : Le single stage A19
and A28 thermostat est destiné à
transmettre des données entrantes
à un équipement dans des
conditions normales de
fonctionnement. Lorsqu'une
défaillance ou un
dysfonctionnement thermostat
risque de provoquer des blessures
ou d'endommager l'équipement
contrôlé ou un autre équipement, la
conception du système de contrôle
doit intégrer des dispositifs de
protection supplémentaires. Veiller
dans ce cas à intégrer de façon
permanente d'autres dispositifs,
tels que des systèmes de
supervision ou d'alarme, ou des
dispositifs de sécurité ou de
limitation, ayant une fonction
d'avertissement ou de protection en
cas de défaillance ou de
dysfonctionnement du thermostat.
WARNING: Risk of Property
Damage.
Do not install the A19 or A28
temperature controls with general
purpose enclosures in any type of
agricultural environment defined in
NEC Art. 547 where dust or dust
with water may accumulate or
where corrosive atmospheres exist.
Failure to comply with NEC Art. 547
may cause the A19 or A28 control
to fail and result in the loss of
temperature regulation and
damage to other property.
MISE EN GARDE : Risque de
dégâts matériels.
Ne pas installer les régulateurs de
température A19 or A28 équipés de
boîtiers à usage général dans tout
type d'environnement agricole, tel
que défini dans l'article 547 du
National Electrical Code (NEC, Code
électrique national des États-Unis),
dans lequel ils pourraient être
soumis à l'accumulation de
poussière ou de mélange
poussière/eau, ou à une atmosphère
corrosive. Le non-respect de l'article
547 du NEC risque d'entraîner une
défaillance du régulateur A19 or A28
et de provoquer l'interruption de la
régulation thermique et d'autres
dégâts matériels.
Operation
Figs. 4 and 5 illustrate the
operation of the A19. On a
temperature increase, the circuit
between R and Y closes.
Simultaneously the R and B circuit
opens.
Figure 6 illustrates the operation of
the A28AA. On a temperature
increase, the circuit between R and
Y of the low stage switch (RYL)
closes. Simultaneously, the circuit
between R and B (RBL) opens.
Fig. 1 -- Exterior view of Space
Thermostat
On a further increase in
temperature, the high stage switch
operates and closes RYHwhile
simultaneously opening RBH.
The reverse sequencing takes
place on a temperature fall.
Installation
Mounting
Mount control to a flat surface with
screws through holes provided in
back of frame.
IMPORTANT: On rough mounting
surfaces, use the top two
mounting holes only. When
these controls are mounted
on an uneven surface using
screws in all four holes, the
case can be twisted enough
to affect the thermostat’s
calibration and operation.
Mount the control where it is
exposed to the average
temperature of the controlled
space. Do not mount where it will
be affected by unusual heat or cold,
such as directly over an animal
stall, in sunlight, or on an outside
wall. Avoid locations near a door,
window or hay chute.

2 A19BAC, A28AA Installation Instructions
IMPORTANT: Do not dent or
deform the sensitive bulb of
this thermostat. A dent or
deformation will change the
calibration and cause the
thermostat to cycle at a
temperature lower than the
dial setting.
Adjustment
Knob adjustment or screwdriver slot
is supplied on the range screw. Dial
pointer is located on adjustment
stop bracket on knob and
screwdriver adjustment models.
Before removing the cover, verify
that all power to the thermostat and
associated equipment is turned off.
!
WARNING: Risk of
Electric Shock.
Disconnect or isolate all power
supplies before making
electrical connections. More
than one disconnection or
isolation may be required to
completely de-energize
equipment. Contact with
components carrying
hazardous voltage can cause
electric shock and may result
in severe personal injury or
death.
AVERTISSEMENT : Risque
de décharge électrique.
Débrancher ou isoler toute
alimentation avant de réaliser
un branchement électrique.
Plusieurs isolations et
débranchements sont peut-être
nécessaires pour -couper
entièrement l'alimentation de
l'équipement. Tout contact
avec des composants
conducteurs de tensions
dangereuses risque d'entraîner
une décharge électrique et de
provoquer des blessures
graves, voire mortelles.
Solid cover models are adjusted by
removing cover and moving dial so
that the setpoint is in line with the
dial pointer on the stop bracket.
(See Fig. 3.)
Convertible adjustment models can
be field converted from concealed
screwdriver slot adjustment to knob
adjustment or external screwdriver
slot adjustment. They are supplied
with a snap-in plug in the cover to
provide concealed screwdriver slot
adjustment. For knob adjustment
remove the snap-in plug and press
the knob onto the slotted shaft. For
external screwdriver slot
adjustment remove the snap-in
plug.
The A28AA switch is stamped to
indicate the HI-TEMP switch and
the LO-TEMP switch.
Fig. 2 -- The Space Thermostats
with convertible adjustment have
a snap-in plug in the cover, built-
in screwdriver slot and a knob
for field installation.
A high temperature adjustment stop
is supplied on the thermostats.
(See Fig. 3.) If adjustment stop is
required:
1. Set dial to temperature at
which stop is desired.
2. Remove cover from
thermostat.
3. Loosen the adjustment stop
screw, slide the screw to the
front of the thermostat against
the plastic stop cam behind the
dial and tighten the screw.
(See Fig. 3.)
Sometimes an exact stop
setting is not possible and stop
must be set to the closest step
corresponding to dial setting
required.
4. Turn dial to setpoint desired.
5. Replace cover.
Wiring
!
WARNING: Risk of Electric
Shock.
Disconnect or isolate all power
supplies before making electrical
connections. More than one
disconnection or isolation may be
required to completely de-energize
equipment. Contact with
components carrying hazardous
voltage can cause electric shock
and may result in severe personal
injury or death.
ADVERTISSEMENT : Risque de
décharge électrique.
Débrancher ou isoler toute
alimentation avant de réaliser un
branchement électrique. Plusieurs
isolations et débranchements sont
peut-être nécessaires pour -couper
entièrement l'alimentation de
l'équipement. Tout contact avec
des composants conducteurs de
tensions dangereuses risque
d'entraîner une décharge électrique
et de provoquer des blessures
graves, voire mortelles.
All wiring should conform to local,
national, and regional codes. Use
copper conductors only. Do not use
on applications where electrical
ratings exceed ratings shown on
the thermostat’s cover label.
See Figs. 4 through 11 for typical
wiring applications.
Note: Use terminal screws
furnished (8-32 1/4 in. binder
head). Substitution of other screws
may cause problems in making
proper connections.
Checkout Procedure
Before leaving the installation,
observe at least three complete
operating cycles to be sure that all
components are functioning
correctly.

A19BAC, A28AA Installation Instructions 3
Check for correct operation in the
following manner.
1. A19BAC -- Ventilating or
Cooling: Turn dial clockwise to
a setting above space
temperature. Fan or cooling
system should be off. When
you turn the dial
counterclockwise, the fan or
cooling system should turn on
approximately at the dial
setting.
A19BAC -- Heating: Turn dial
clockwise above the space
temperature; the heating unit
should be on. When you turn
the dial counterclockwise, the
heating unit should turn off
approximately at the dial
setting.
2. A28AA -- If wiring is similar to
Fig. 8, fan should start at
approximately space
temperature and should
change to high speed as the
dial is turned counterclockwise
to a lower temperature setting.
If similar to Fig. 9, the damper
should open as the dial is
turned counterclockwise. The
devices should act in reverse
sequence when the dial is
turned clockwise to a higher
setting.
3. If control devices do not
operate in the manner
described above, check all
wiring for short circuits and
tightness of wiring
connections. If controlled
devices operate in reverse
(start in high or fully open
position), check wiring.
Repairs and Replacement
Field repairs must not be made. For
replacement thermostat contact the
nearest Johnson Controls
distributor.
AdjustmentStopBracket
withSlotandScrew
Fig. 3 – All models have a screw
type adjustment stop. Loosen
and move stop screw to the stop
setting desired. Tighten screw
after setting is made.
Electrical Ratings
A28AA*
A19BAC
Volts, AC 120 208 240 277 120 208 240 277
Full Load Amp
16.0 9.2 8.0 -- 16.0 9.2 8.0 --
Locked Rotor Amp
96.0 55.2 48.0 -- 96.0 55.2 48.0 --
Non-Inductive Amp
SPDT
SPST
16.0
9.2
8.0
7.2
16.0
16.0
16.0
16.0
16.0 9.2 8.0 7.2 22.0 22.0 22.0 22.0
Pilot Duty
125 VA, 24 to 277 VAC 125VA, 24 to 600 VAC
* Max connected load not to exceed 2000 VA.

4 A19BAC, A28AA Installation Instructions
Fig. 5 – A19BAC typical ventilating or cooling control
circuit.
Fig. 6 – Switch action of the A28AA two-stage control.
, RYHindicate HI-TEMP. RBL, RYLindicate LO-TEMP. D
is the differential between stages.
*Disconnecting means and overload protection as required.
Fig. 4 – A19BAC typical heating control circuit.
RBH

A19BAC, A28AA Technical Bulletin 5
European Single Point of Contact:
NA/SA Single Point of Contact:
APAC Single Point of Contact:
JOHNSON CONTROLS
WESTENDHOF 3
45143 ESSEN
GERMANY
JOHNSON CONTROLS
507 E MICHIGAN ST
MILWAUKEE WI 53202
USA
JOHNSON CONTROLS
C/O CONTROLS PRODUCT MANAGEMENT
NO. 22 BLOCK D NEW DISTRICT
WUXI JIANGSU PROVINCE 214142
CHINA
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