New HVAC design group created called

New HVAC design group created called

Post by Conr » Sun, 14 Nov 1999 04:00:00

Hi all

For you use and information there is a new HVAC design group created
called  If it does new show up on your server you can
request you administrator to add it to the current lot.

The focus of this group will be design of commercial systems.



1. BAD DESIGN??? RCS X-10 Thermostat / HVAC system

I wonder now about RCS as a reliable X-10 design
house. Tell me if I am wacked:

I installed their X-10 Thermostat system: a controler
that interfaces to your heater and a TW523 and
LED thermostat (that replaces the original one in your

It worked fine at first. Then I checked on it and found the
LED's on the controller (that connects to the TW523 and the
heater) had little status LED's that were not working - DEAD.

I looked carefully and found that on the "Power LED", they
tied one side to +5V regulated and the other to ground,
4 others ("Fan", "Heat", "Cool", ...) and found that one
side was tied directly to +12 V and the other through a
2003 driver, DIRECTLY, also with NO CURRENT LIMITING
RESISTOR.  No wonder most of the LED's don't work any more.

(Is there a new kind of LED? Am I missing something here?)

Do other people with these things have failing LED's?

Has anyone else noticed any other poor design characteristics?

What might be NEXT to fail?


             Andrew Ward
      phone: 408 527-2773               |           |
             800.250.4800 ext 72773     |           |  
 department: Core Products             |||         |||

                                  C i s c o   S y s t e m s

2. Panasonic 32x

3. New Design Patterns Study Group in New York City

4. Removing velcro pad from back of PIII

5. call for papers on computer design: new grand challenge

6. Scheme to VMS exe file conversion, plus SIOD has regular expressions.