Trane Tracer UC400 - Heating, Cooling, and Auto-Changeover Logic

42 VAV-SVX07F-EN
Calibration, Operation Modes, and Control
On/Off Electric Reheat
The Airflow Setpoint Minimum Local Heat is enforced during reheat.
On/Off hot
water
(1 stage)
Not applicable
Local thermostatic:
•On: Zt < HSP
• Off: Zt  HSP + 0.5°F (0.28°C)
Not applicable Not applicable
Total capacity is limited by
communicated
supply heat control
Not applicable Not applicable
Modulating hot
water
Not applicable
• Local PI capacity loop
Modulating valve capacity = Total capacity 
Valve drive incrementally open/closed 
Total capacity limited by communicated supply heat control
Not applicable
Table 10. Local Heat Only With Parallel Fan Present
Configuration Method of Control
Local Remote Fan Stage 1 Stage 2 Stage 3
Fan
Not
applicable
Par
allel fan Not applicable Not applicable Not applicable
Fan and PWM
electric (1 to
3
stages)
Not
applic
able
Par
allel fan
• Local PI capacity loop.
• Each stage represents an equal
percentag
e of total capacity PWM
Output (one stage = 100%; two
stages = 50% each; three stages =
33.33% each).
• Total capacity is limited by
c
ommuni
cated supply heat control.
• Local PI capacity loop.
• Each stage represents
an equal
percent of total capacity
• (1 stage = 100%, 2 stages = 50% each).
•PWM output.
Total capacity is limited by communicated supply heat control.
SCR electric
Not
applicable
•Local PI
capacity loop
•SCR heat
cap
acity =
to
tal
capacity
•Total
cap
acity
lim
ited by
communicat
ed supply
heat control
Not applicable Not applicable SCR electric
Fan and On/Off 
electric (1 to 3 
stages)
Not
applicable
Par
allel fan
Local thermostatic:
•On: Zt < HSP
• Off: Zt HSP + 0.5 °F (0.28°C)
Local thermostatic:
• On: Zt < HSP - 1°F (0.56°C)
• Off: Zt  HSP - 0.5°F (0.28°C)
Local thermostatic:
• On: Zt < HSP - 2°F (1.11°C)
• Off: Zt  HSP - 1.5°F (0.83°C)
• Each stage represents an equal
percentag
e of total capacity.
• Total capacity is limited by
c
ommuni
cated supply heat control.
• Each stage represents an eq
ual percentage of total capacity.
• Total capacity is limited by communicated supply heat control.
Fan and On/Off
hot water (1 to 3
stages)
Not
applic
able
Par
allel fan
Local thermostatic:
•On: Zt < HSP
• Off: Zt  HSP + 0.5°F (0.28°C)
Local thermostatic:
• On: Zt < HSP - 1°F (0.56°C)
• Off: Zt  HSP - 0.5°F (0.28°C)
Not applicable
Total capacity is limited by
communicated su
pply heat control.
Total capacity is limited by
communicated su
pply heat
control.
Not applicable
Fan and
Modula
ting hot
water
Not
applicable
Par
allel fan
• Local PI capacity loop.
• Modulating valve capacity = Total
capac
ity.
• Valve drive incrementally open/
cl
osed
.
• Total capacity limited by
c
ommuni
cated supply heat control.
• Local PI capacity loop.
• Modulating valve capacity = Total capacity.
• Valve drive incrementally open/closed.
• Total capacity limited by communicated supply heat control.
Table 9. Local Heat Only With No Fan Present (continued)
Configuration Method of Control
Local Remote Stage 1 Stage2 Stage 3