Fan Code not working like expected

[dgrego]

With the following code the fan turns on at 79.3 and off at 79.2
What am I missing?

If Temp > 79.2 Then FAN ON
If Temp < 78.6 Then FAN OFF

[SWINGRRRR]

Edit- Maybe theres just a small delay in the actual thinking>change noticed> change given.

I think the program reads from top to bottom and then starts all over. So its running and the temps are changing. When it hits the temp parameters it follows the program. Just takes it a second.



I am a newbie to AC so Im just taking a stab in the dark...

[dgrego]

If Time > 00:00 Then ALM OFF
If Time > 00:00 Then TZR ON
If Time > 00:00 Then TZL ON
If Time > 00:00 Then SKM ON
If Time > 00:00 Then RTN ON
If Time > 00:00 Then CAC ON
If Time > 08:00 Then ACL ON
If Time > 12:00 Then DYL ON
If Time > 16:00 Then DYL OFF
If Time > 20:00 Then ACL OFF
If Timer ACL = ON Then MNL OFF
If Timer ACL = OFF Then MNL ON
If Timer DYL = ON Then SPL OFF
If Timer DYL = OFF Then SPL ON
If Temp < 78.0 Then HT1 ON
If Temp > 78.5 Then HT1 OFF
If Temp > 79.2 Then FAN ON
If Temp < 78.6 Then FAN OFF
If Temp > 82.0 Then DYL OFF
OSC 005/235 ON/OFF Then STR ON
If Timer STR = OFF Then TOP ON
If Timer STR = ON Then TOP OFF
Max Change 050 M Then TOP OFF
If pH > 08.40 Then TOP OFF
If Timer RTN = OFF Then HT1 OFF
If Timer RTN = OFF Then TOP OFF
If FeedA 000 Then TZR OFF
If FeedA 000 Then TZL OFF
If FeedA 000 Then RTN OFF
If pH2 > 06.50 Then CO2 ON
If pH2 < 06.40 Then CO2 OFF
Max Change 002 M Then CO2 OFF
If Temp < 76.0 Then ALM ON
If Temp > 82.0 Then ALM ON
If pH > 08.40 Then ALM ON
If pH < 07.80 Then ALM ON


ACL$-A1
DYL$-A2
MNL$-A3
SPL$-A16
TZR#-A4
TZL#-A10
SKM#-A15
RTN#-A14
STR%-A7
HT1%-A12
FAN%-A8
CAC&-A8
CO2&-A6
TOP#-A5
ALM#-M1

[SWINGRRRR]

You are looking for it to hold half of a degree constant. I would broading the temp swing a little. Mine is from 78-80. My max is 83. At 83 things start shutting down.

[dgrego]

I see A8 used twice. I'll correct this and see if it makes any difference

[jdieck]

Fix the A8 address asignment and also I would remove the second statement and just leave it as:
IF Temp > 78.9 Then Fan ON

[kenargo]

2 timers at the same address is really bad and causes the AC to get confused......

jdieck, you can't use a single statement, because you need something to tell the FAN to when to turn off otherwise it will turn on and stay on forever.

You can use what you have:

If Temp > 79.2 Then FAN ON
If Temp < 78.6 Then FAN OFF

or you can do:

If Time > 00:00 Then FAN Off
If Temp > 79.2 Then FAN ON

They are both functionally the same.

[dgrego]

Since I removed the duplicate timers, I'm going to monitor the fans response to see what happens.

Thanks, All

I'll post when I get results