[TRNSYS-users] Type8a: Setback temperature issue

[Kent Beason]

Paul, 

I recently had the same problem with Type8a.  Related to your #2 conditions below, set your "Heating set back temperature difference" to zero and see if the heating stage operates then.  My experience with 8a says it will work, but of course with a useless setback function.  I ended up throwing out Type 8a in my simulation and easily using Type 671 from the TESS library.

Kent Beason
Schlitterbahn Development Group
830-609-8904 m
 
-----Original Message-----
From: PAUL COALES [mailto:coalespr at btinternet.com] 
Sent: Monday, December 07, 2009 7:29 AM
To: trnsys-users at cae.wisc.edu
Subject: [TRNSYS-users] Type8a: Setback temperature issue

Hi 

Are there any issues with Type8a, setback function?  The instructions for use seem straight forward but it does not seem to work for me:

1) If INPUT "Set back control function" is fixed at 0, setback behaviour is disabled.  "Control signal for 1st stage heating" is set when  "Room temperature" drops below "1st stage heating temperature".  This behaviour seems correct.

2)If INPUT "Set back control function" is fixed at 1, setback behaviour should be enabled.  However, the "Control signal for 1st stage heating " is never set.  My heating system never turns on and my room temperature continues to fall.

I've set "minimum primary source temperature" to a low value (10 degrees)  "1st stage heating in 2nd stage" is set to 1.  "Heating set back temperature difference" is set to 1 deltaC


Have I missed something?

Paul