WattMaster VAV System - Manual (Page 21)

Operator Interfaces
Technical Guide
21
Setpoint Screen #26
WMVAV Spts ID 59
Internal Schedule
Optimal Start Soak
Multiplier: X.X
If you have decided to use the AHU internal schedule and entered a ‘0’
on the previous screen for the schedule number, you can enable this
internal schedule to perform an optimal start. This feature requires a
Space Sensor input for the optimal start calculations. If you don’t
require optimal start or you are not using a space sensor, enter a ‘0’ for
this multiplier. If you do have a space sensor and want optimal start,
enter a value greater than ‘1.0’ to enable the calculations. The soak
multiplier is used to increase the normal optimal start calculation when-
ever the building has been in the unoccupied mode for 24 consecutive
hours or more. If you used a 1.5 multiplier and the optimal start had
calculated a 30 minute pre-start, the soak multiplier would add an ad-
ditional 15 minutes to the pre-start for a total of 45 minutes (1.5 x 30).
The system would then start 45 minutes earlier than the normally sched-
uled occupied mode schedule to bring the space temperature under
control.
Description Minimum Default Maximum
Multiplier 0.0 0.0 5.0
Setpoint Screen #27-30
WMVAV Spts ID 59
Cooling Stage Delays
Staging Up..: xx Min
Staging Down: xx Min
WMVAV Spts ID 59
Cooling Stage Delays
Min Run Time: xx Min
Min Off Time: xx Min
WMVAV Spts ID 59
Heating Stage Delays
Staging Up..: xx Min
Staging Down: xx Min
WMVAV Spts ID 59
Heating Stage Delays
Min Run Time: xx Min
Min Off Time: xx Min
Both the Heating Stages and the DX Cooling Stages utilize Staging Up
and Down delay periods between stages and Minimum Run Times and
Off Times.
Both modes have their own set of staging and run delay times. The
Heating timer screens look exactly the same as the cooling except they
reference the Heating instead of Cooling.
See the Sequence of Operation Manual for information on how these
delays and run times are used.
Description Minimum Default Maximum
Cooling Stage Up 3 Min 3 Min 15 Min
Cooling Stage Down 1 Min 1 Min 15 Min
Cooling Min Run Time 5 Min 5 Min 15 Min
Cooling Min Off Time 3 Min 3 Min 15 Min
Heating Stage Up 3 Min 3 Min 15 Min
Heating Stage Down 1 Min 1 Min 15 Min
Heating Min Run Time 2 Min 2 Min 15 Min
Heating Min Off Time 1 Min 1 Min 15 Min
Setpoint Screen #31 & 32
Sensor Calibration
SPC: xx.x
° xx.x °
SAT: xx.x ° xx.x °
RAT: xx.x ° xx.x °
Sensor Calibration
OAT: xx.x
° xx.x °
The Thermistor Type III sensor readings can be calibrated. Enter a Posi-
tive value to increase a reading and a Negative value to decrease a read-
ing.
Description Minimum Default Maximum
Space Sensor SPC -100.0
°
F 0.0
°
F +100.0
°
F
Supply Sensor SAT -100.0
°
F 0.0
°
F +100.0
°
F
Return Sensor RAT -100.0
°
F 0.0
°
F +100.0
°
F
Outdoor Sensor OAT -100.0
°
F 0.0
°
F +100.0
°
F