Replacement for a Johnson DX9100 version 2 and XT extension module
Peter Grove
DX9100 central heating controller which has caused much grief of lately.
The prolems as I understand them are:-
1. One or two of the control modules appear to partially corrupt
occassionally requiring that module to be reset and re-programmed.
2. The controller is not straight forward to override or re-program for the
uninitiated - it is used in a church where heating requirements cannot be
set against a routine and where more than a couple of people need to be able
to operate the controller. I guess this explains some of the apparent
corruptions in the modules but not all.
3. I think there have been other problems in the past which has resulted in
Johnson Controls engineers replacing EPROM and possibily other items.
The bottom line is that people are fed up with Johnson Controls engineers'
bills, the reliability of the controller even when there is a routine in the
heating requirements and the awkwardness of programming it or overriding it.
Are these common problems with this controller?
Can anyone recommend another controller which is simple to operate? How
much do these cost?
Basic details of the system as it is at the moment are as follows
7 Analogue inputs
1 Analogue output
9 Digital outputs
3 Heating Zones
I believe one of the analogue inputs and one of the digital outputs could be
done away with if need be
All the zone valves, pumps and boilers work fine.
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reply to peterdotgroveatwhichdotnet
Jason McGehee
A new product for the DX-9100 is the DT-9100 Display Unit. It is very user
friendly for displaying point information, scheduling, commanding points,
and displaying alarm conditions It can display a simple graphic. It mounts
on a wall or panel face or can be a hand held unit. The DX can be a funky
controller for interfacing because it is based on International Standards.
Your local Johnson Controls branch or Authorized Building Control Specialist
can help you out.
Jason McGehee
Gyhooyabat
First question; what HVAC WINPRO program is being used in this controller?
Second; is it a Johnsons American version of controller or is it an universal
version?
Third; What means of access to the controller is being used? I.E. a ZT100
control, front end computer or just the access key that is plugged into the
controller.
1. check the time clock and day of week schedule in the controller.
2. Do they have the book that came with the controller that explains how to
override set points and even change them if need be? If the program is not ment
to be tampered with then that is why you cannot override.
Yes Johnsons has had a few problems with there earlier versions of the DX
controller, but the 2.0 and 2.4 versions are at the top of the list when it
comes to DDC controls.
3. Do they make a simple controller? No, and no other brand or company does.
Unless you understand how the controller works from begining to end then they
will all appear to be very difficult to operate.
Do they cost much? Yes!
Before you blame the controller, maybe you might like to take a look at the
sensors and controls on the outside of this controller. If you are using a
nickle plated resistor for you AI1 input, but the sensor is a platnum sensor
then you will receive false readings into the controller, it is not the
controllers fault. It will only do what you tell it to do. Also, it is common
for resistive sensors to fade as they get older, they would be much cheaper to
replace then a new controller. If they are resistive sensors, then measure the
resistance of the sensor at the controller and verify that the controller is
reading the corrrect temperature compared to the resistance. Note; 1000 ohms of
resistance of a nickle plated resistor is the equivelant 71.5 degrees F. You
can always go onto Johnsons web site and pull up there resistance to
temperature chart and print out a copy of it for yourself.
What are the input and output signals that you feel could be removed? If one of
them is outside air temp. then there is a great possibility that the controller
will fail into a full heating mode. That sensor and it's input are normally the
heart of the controllers operation. Again, it depends on what version of
program you are using and how it was set up to begin with.
By the way, ther are now 7 versions of the HVACPRO that could be being used.
Please feel free to respond and I will attempt to help you anyway I can. My
e-mail address is gyhoo...@aol.com
My name is John
Eldon Ziegler
churches as well as office buildings with major brand HVAC systems. The
graphic "user friendly" interface is one of the features we get consistent
user compliments on.
Our web site has more information at http:\\www.homation.com or call
1-800-522-6054.
Peter Grove wrote in message <6vj4t6$n7e$1...@nclient1-gui.server.which.net>...