KMC Controls BAC-8007 Installation Guide - Manual (Page 66)

Parallel Fan
If the controller is configured for a parallel fan, any time the Occupancy mode
of the controller is set to either
Occupied or Standby and there is a call for
heat, the fan runs continuously. The fan starts when the Heating loop is
greater than 5% and stops when the Heating loop is less than 1%.
When the unit Occupancy state is Unoccupied , the fan starts and runs at
minimum speed only on a call for heating. The fan starts when the Heating
loop is greater than 5% and stops when the Heating loop is less than 1%.
Illustration 7–3 Parallel fan operation
MAX FAN SPEED
MIN FAN SPEED
FAN OFF
OCCUPIED
HTG SP ROOM TEMP INCREASE
UNOCCUPIED/
STANDBY
Reheat sequence The SimplyVAV controllers can control four types of reheat installations.
Modulating reheat
Staged reheat
Time proportioned reheat
Floating reheat
All reheat is controlled by either the Heating loop or the Discharge Air Temp
Limiting (DAT) PID loop. Loops are described in the topic
PID control loops
on page 61 .
If Discharge Air Temp Limiting is enabled, reheat is controlled by the
DAT PID loop.
If DAT control is not enabled, reheat is controlled by the Heating loop.
In the following descriptions, the loop controlling reheat is referred to as the
Reheat loop.
Modulating reheat
If the controller is configured for modulating reheat, it controls an analog
reheat unit with 0-10 volts DC at the analog reheat output. On a call for
Section 7: Sequences of operation SimplyVAV
66 Revision E