Installation and Maintenance Manual

Diagnostics
UV-SVN02C-EN 105
3. VSP Inputs (0–10V inputs) are of the wrong polarity
– Verify that variable speed (VSP) inputs ar
e properly
wired to 1TB4.
Notes:
• Do not short the courtesy 10 Vdc supply to chassis
or loads that require greater than 10 mA of DC
current.
• Please observe proper polarity of 0–10 Vdc inputs.
Failure to observe proper polarity can cause failure
of the ECM engine board, the customer-supplied
controller or the Tracer ZN controller.
4. Customer Controller output signal to VSP Inputs are
too low
.
Note: If the
customer supplied controller outputs
signals that are below the noise threshold, they
will be ignored by the ECM Engine.
– The ECM Engine board contains an adjustable
noise floor parameter,
 that can be configured
to reject signals below the noise floor.
– If the noise floor parameter is set too high, it can be
lowered as long as there are acceptable noise levels
on the inputs lines.
Troubleshooting a motor that spins too fast, or
spins without any apparent speed request
(ECM)
Typical equipment and controls design practice will
ensure that the fans will come on if there is a call for heat,
cool, or ventilation. In most cases, we will depend on the
controller/thermostat to call for the fan to come on when
appropriate, but during calls for electric heat, or calls for
heat on CSTI units equipped with electric heat, as a call for
the appropriate fan speed. This behavior, as described
previously, is an indirect request.
When a call for electric heat is made, the system will
positively drive the fan on to the correct speed, regardless
of whether the controller has asked for fan operation or
not. The unit design incorporates an interlock instead of a
lock-out. (It does not lock out electric heat if the fan is set
to off; it brings the fan on.)
Notes:
• In many cases, indirect requests will result in fan
behavior change regardless of whether the end-device
fails to actuate (due to device failure, or safety/down-
stream lockouts). If there is hot water available on CSTI
units with changeover coils and electric heat, we will
still drive the fan to the appropriate electric heat speed.
• The new fan coil designs incorporate sophisticated fan
interlocks that will lockout heat if there is a fan failure.
If the preceding conditions do not describe the behavior of
the unit, the following checks should be performed:
• Verify that the voltage jumper on
the motor plug
harness is absent for 208-230V units and 277V units. If
the jumper is present for these units, the motor
electronics will be damaged, and the motor will not be
controllable.
• Verify that the fan speed requ
est is not below 450 rpm.
Speeds below 450 rpm are not supported on the fan-
coil product.
• Verify that the all binary inputs to the customer
ter
minal blocks are of proper and consistent polarity.
– For CSTI units, the fan inputs and end device inputs
on TB3 must
receive signals that are 24 Vac with
respect to the unit chassis.
Note: Do not short 24 Vac (pos 1 or pos 2) to
chassis; refer to the unit schematic.
– For Fan Speed Switch units, that incorporate the
Tracer ZN/CSTI adapter board, all inputs to TB3
must be 24 Vac with respect to unit chassis.
Note: Do not short 24 Vac (pos 1 or pos 2) to
chassis; refer to the unit schematic.
– For Tracer ZN units, where there is a desire to use
parallel fan inputs on the adapter board TB3 strip,
the inputs must be COM (i.e., the inputs will honor
only 0 V with respect to unit chassis).
Note: Do not short 24 Vac (pos 1 or pos 2) to
chassis; refer to the unit schematic.
• Verify that variable speed (VSP)
inputs are properly
wired to 1TB4.
Notes:
• Do not shor
t the courtesy 10 Vdc supply to chassis
or loads that require greater than 10 mA of DC
current.
• Please observe proper polarity of 0–10 Vdc inputs.
Failure to observe proper polarity can cause failure
of the ECM Engine board, the customer-supplied
controller or the Tracer ZN controller.
• Verify that the signal on the VSP
inputs is noise free.
The ECM engine board contains an adjustable noise
floor parameter,
, that can be configured to reject
signals below the noise floor.
Note: If t
he customer supplied controller outputs
signals that are below the noise threshold, they
will be ignored by the ECM engine.
• Verify that VSP input settings are correct. The ECM
en
gine board contains an adjustable digital amplifier,
, to compensate for long 10 Vdc cable runs. For
normalized (0–10 Vdc) signals, this setting should be
se
t to 1.000. If it is set too high, the motors will faster
than the requested ratio, and will hit the limit 
before the input voltage has reached its upper limit.
• Verify that
 and , the low motor signal
output limits, are set correctly.
UV-SVN02_-EN.book Page 105 Thursday, January 24, 2013 4:48 PM