iWorx® HPU2
10
502-025, Effective: April 12, 2011
© 2011 Taco Electronic Solutions, Inc.
Equipment Status (EQS)
To connect the equipment switch to the digital input, attach one wire of the contact to EQS (T5) and the other wire to
the adjacent common (T6). This must be a dry contact, normally open switch which closes when flow is detected. If a
flow proof switch is not installed, the terminals should be connected with a jumper wire.
Space Temperature (ST, optional)
To connect a thermistor (Precon II or Precon III) to the analog input, attach one wire of the sensor to ST (T7) and the
other wire to the adjacent common (T6). The thermistor can be used if no TS300 series thermostat is being used.
Connecting Output Devices
Stage 1 & Stage 2 (S1, S2)
The outputs for the stages must be connected to 24 VAC pilot relays if the load is greater than 1 Amp for each pump. If
the load is less than 1 Amp, connect stage 1 to S1 (T28) and adjacent TC34 (T27), and connect stage 2 to S2 (T26)
and adjacent TC34 (T27)
Reversing Valve (RV)
The output for the reversing valve must be connected to a 24 VAC pilot relays if the load is greater than 1 Amp. If the
load is less than 1 Amp, connect the reversing valve input to RV (T29) and adjacent TC12 (T30).
Fan (FAN)
The output for the fan must be connected to a 24 VAC pilot relay if the load is greater than 1 Amp. If the load is less
than 1 Amp, connect the fan input to FAN (T31) and adjacent TC12 (T30).
Other Connections
Network (LON)
Network wiring must be twisted pair. One network wire must be connected to terminal NETA (T1) and the other network
wire must be connected to terminal NETB (T2). Polarity is not an issue since an FTT-10A network is used for commu-
nications.
Power (PWR)
Connect one output wire from a 24 VAC power supply to PWR (T39) and the other output wire from the power supply to
the adjacent common terminal (T38).
Ground (GND)
Terminal GND
(T40) 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.
SPECIFICATIONS
Electrical
Inputs
• Cabling: twisted shielded pair, 18 AWG recommended—500 feet max. (152 meters)
• Resolution: 10 bit
