27
control SiGnal & Mode
oPeration
total KW
Board action
W
EHEAT
On
5 KW
Stage 1 Heat on instantly
Heat blower on after 3 second delay
10 KW
Stage 1 Heat on instantly
Heat blower on after 3 second delay
Stage 2 Heat on after 5 seconds delay
15 KW
Stage 1 Heat on instantly
Heat blower on after 3 second delay
Stage 2 Heat on after 5 seconds delay
Stage 3 Heat on after 10 seconds delay
20 KW
Stage 1 Heat on instantly
Heat blower on after 3 second delay
Stage 2 Heat on after 5 seconds delay
Stage 3 Heat on after 10 seconds delay
Stage 4 Heat on after 15 seconds delay
Off
Heat stages off instantly
Blower off after 15 second delay
W & Y
AUX HEAT
On
5 KW
Stage 1 Heat on instantly
Cool blower on after 3 second delay
10 KW
Stage 1 Heat on instantly
Cool blower on after 3 second delay
Stage 2 Heat on after 5 seconds delay
15 KW
Stage 1 Heat on instantly
Cool blower on after 3 second delay
Stage 2 Heat on after 5 seconds delay
Stage 3 Heat on after 10 seconds delay
20 KW
Stage 1 Heat on instantly
Cool blower on after 3 second delay
Stage 2 Heat on after 5 seconds delay
Stage 3 Heat on after 10 seconds delay
Stage 4 Heat on after 15 seconds delay
Off
Heat stages off instantly
Heat blower turns off after 40 second delay
G
FAN
On
Cool blower on after 3 second delay
Off
Cool blower off instantly
Y HEAT PUMP
& COOL
On
Cool Blower on after 3 second delay
Off
Cool Blower off after 40 second delay
table 10. Heating element logic for MB7BM air Handlers