Delta Controls BACstat II Series User Manual

Delta Controls
Document Edition 3.1
Page 13 of 35
Lockout Modes
Heating and cooling lockout modes are operational for all Control Applications.
Basically, once a BACstat has been configured for various stages of heating and cooling, either the heating and/or
cooling may be disabled on-the-fly as necessary for various control strategies simply by commanding the Alg.
Mode (AV13). In all other regards, control continues to function the same as it would when in Occupied mode.
Communications Reset Enable
The Algorithm Mode variable also has a property represented by a checkbox in the object dialog called Comm
Reset Enable. This can be enabled or disabled, depending on the requirements of the installation.
Disabled
Enabled (the default as of Release 3 Firmware)
• The BACstat does not try a reset on the loss
of communications
• Should the device reset, the mode reverts to
whatever it was just prior to the reset (i.e., last
value as stored in non-volatile memory)
• The BACstat will reset once on the loss of
communications to try to re-establish
communications
• Should the device reset, the mode is set to
DAY
3. BOX MODE (DNT-T103 AND DNT-T221 ONLY)
When the application control strategy is configured for either VAV or VVT, the Box Mode (variable AV33) can
be set to either cooling (default) or heating. When set to cooling, the air supply is treated as the first stage of
cooling. When set to heating, the cooling controller is inverted and the air supply is treated as the first stage of
heating.
Box Mode Description AV33
Cooling Duct Supply Air to the box provides cooling (default) 0
Heating Duct Supply Air to the box provides heating 1
Note that this variable cannot be commanded or changed from the BACstat. As this function is completely
dependent on the air supplied to the boxes from another source, this variable would normally be commanded over
the network (i.e., typically via GCL) whenever the air system changes between heating and cooling.
N
OTE: In Release 3, VAV and VVT applications can no longer be configured with more than 1 stage of cooling.
In earlier releases of firmware, do not configure a BACstat with more than 1 stage of cooling, as
additional stages of cooling don’t work properly when Box Mode is ever set to heating.
SOFTWARE LOOP CONTROLLER (DNT-T103 and DNT-T221 Only)
1. GENERAL
The operation of the BACstat II is centered around a software controller. The controller uses the following
parameters in its operation.
Parameter Object Default Value Notes
Room Temperature AI1 N/A Input 1 **
Temperature Setpoint* OCCUPIED: Uses Day Setpoint (AV6)
U
NOCCUPIED: Uses Night Heat Setpoint
(AV10) if the Input is below the Day Setpoint
(AV6); and uses the Night Cool Setpoint
(AV11) if the Input is above the Day Setpoint
(AV6); otherwise it is in a null zone.
Proportional Band AV19 4.0 ºF / 2.0 ºC Degrees F or C as configured for AI1
Reset Rate AV20 1.0 Resets per hour
Day Differential AV9 1.0 ºF / 0.5 ºC Degrees F or C as configured for AI1
* Humidity Setpoint if operating as a Humidity controller ** Input 3 (AI3) if operating as a Humidity controller

Delta Controls BACstat II Series Specifications

General

Brand	Delta Controls
Model	BACstat II Series
Category	Thermostat
Language	English