iWorx® HPU3
502-035, Effective: February 21, 2012
15
© 2012 Taco Electronic Solutions, Inc.
Troubleshooting Tips
The table below provides solution to some common problems you may encounter.
Getting Help
Components within an iWorx® controller, sensor, or power supply cannot be field repaired. If there is a problem with a
unit, follow the steps below before contacting your local TES representative or TES technical service.
1.Make sure controllers, sensors, and power supplies are connected and communicating to desired devices.
2.Record precise hardware setup indicating the following:
Version numbers of application software.
Device and/or firmware version number.
A complete description of difficulties encountered.
Notes:
Problem
Solution
Controller is not running and Status
LED is not illuminated.
No power to controller. Verify the voltage on the controller’s power connector (24 VAC).
How do I reset the controller?
The controller can be reset by the LCI, or you can cycle power to the controller. Refer to
the LCI documentation for more information on resetting the controller using the LCI.
The fan will not cycle on after the
equipment status input alarm has
been resolved
If the controller was previously in an equipment status fault condition, the controller
must be reset before proper operation can be restored.
The fan and staged pilot relays will
not come on even though the LCI
indicates it is on.
Ensure that the controller and output pilot relay have been powered with 24 VAC and
the output has been correctly wired to the coil of the pilot relay. Also ensure that the pilot
relay has a 24 VAC coil.
The Space Temperature or Supply
Air Temperature thermistor reading is
at its maximum or minimum.
The input is either shorted or open.
The staged outputs will not come on
even though the space requires con-
ditioned air.
Is there water flow in the system? Verify the associated CCU2 or LHP2 controller are
operating and the HPU3 is a member of the controller. If there is no CCU2 or LHP2 con-
nected, then the Unit Enable input of the ASM2 must detect water flow (On).
Thermistor readings fluctuate rapidly,
sometimes by several degrees.
The controller is not properly grounded. The controller's ground (GND) pin (T40) must
be connected to earth ground. Also ensure that the controller's digital inputs are dry
contacts and that no voltage is being applied or switched to the inputs.
How do I associate my HPU3 control-
lers with the LHP2?
Use the LHP2's grouping mechanism, specifically
Members
on the LHP2 HVAC Setup
screen of the LCI. Only HPU3s may be associated with the LHP2.
Under what conditions does the
HPU3 require a reset for normal
operation.
There are two conditions that require a reset:
– Equipment failure and hard pressure failure (alarm)
