iWorx® VAV Series
502-011, Effective: March 16, 2011
9
© 2011 Taco Electronic Solutions, Inc.
Indoor Air Quality (IAQ)
To connect the digital CO
2
level sensor to the unit, attach one wire from the sensor to IAQ (T18) and the other wire to
the adjacent common (T17). The sensor must provide a contact closure when the CO
2
limit is exceeded.
Primary Air Temperature (PAT)
To connect the primary air temperature to the unit, attach one wire from the thermistor to PAT (T19) and the other wire
to the adjacent common (T20). The thermistor used must be 10K Precon Type III.
Occupancy Sensor (OCC)
To connect the digital occupancy sensor to the unit, attach one wire of the sensor to OCC (T21) and the other to the
adjacent common (T20). The sensor must provide a contact closure when the occupancy button is pressed.
Connecting Output Devices
Heating Stages 2 (H1, H2)
The heating stage outputs must be connected to 24
VAC pilot relays with EMF protection. Connect Heat Stage 1 to T5
and the adjacent common on T6. Connect Heat Stage 2 To T4 and the adjacent common on T3. See Figure
2
for
details.
Fan Start/Stop (FAN)
The fan outputs must be connected to a 24
VAC pilot relay with EMF protection. Connect the Fan to T7 and the adja-
cent common on T6. See Figure
2 for details. If the controller is being used with auxiliary heat sources, this output is
used as the auxiliary heat output.
Analog Reheat Valve (AO1)
To connect the reheat valve output, attach one wire to AO1 (T13) and the other wire to the adjacent common (T14).
Other Connections
Network (LON)
Network wiring must be twisted pair. One network wire must be connected to terminal NETA (T11) and the other net-
work wire must be connected to terminal NETB (T12). Polarity is not an issue since an FTT-10A network is used for
communications. Terminals T9 and T10 must be jumpered together.
Power (PWR)
Connect one output wire from a 24 VAC power supply to PWR (T8) and the other output wire from the power supply to
the adjacent common terminal (T9).
Ground (GND)
Terminal GND
(T10) must be connected to earth ground. Failure to properly ground this equipment will
result in improper operation. Improper grounding may also increase the risk of electrical shock, and may
increase the possibility of interference with radio and TV reception.
