2
A19K, A28K Technical Bulletin
Make all wiring connections
using copper conductors only,
and in accordance with the
National Electric Code and local
regulations.
Remove the knob by loosening
the set screw and remove the
cover to make wiring
connections. Make splices in
junction boxes using solderless
connectors or by soldering and
then taping the connections.
Do not use on applications
where electrical ratings exceed
the rating shown on the control’s
label.
!
CAUTION: Use terminal
screws furnished (8-32 ×
1/4 in. binder head).
Substitution of other
screws may cause
problems in making proper
connections.
Adjustment
The setting is changed by
turning knob on front of control.
Checkout Procedure
Before leaving the installation,
observe at least three complete
operating cycles to be sure that
all components are functioning
correctly.
Check for correct operation as
follows:
1. A19K -- Ventilating or
Cooling System: Turn dial
clockwise to a setting above
temperature of controlled
medium. Fan or cooling
system should be off.
When dial is turned
counterclockwise, the fan or
cooling system should turn
on at approximately the dial
setting.
2. A19K -- Heating System:
Turn dial clockwise above
the temperature of
controlled medium. The
heating unit should be on.
When dial is turned
counterclockwise, the
heating unit should turn off
at approximately the dial
setting.
3. A28K -- When wired as
shown in Fig. 3, the damper
should open as the dial is
turned counterclockwise.
The devices should operate
in reverse sequence when
the dial is turned clockwise
to a higher setting.
If the controls 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
as it is probably reversed.
Repairs and Replacement
Field repairs must not be made.
For replacement control, contact
the nearest Johnson Controls
distributor.
www.penncontrols.com
® Johnson Controls and PENN are registered trademarks of Johnson Controls in the
United States of America and/or other countries. All other trademarks used herein are the property
of their respective owners. © Copyright 2019 by Johnson Controls. All rights reserved.
