Installation and Maintenance Manual
Diagnostics
128 UNT-SVX07D-EN
• 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 request is not below 450 rpm.
Spe
eds below 450 rpm are not supported on the fan-
coil product.
• Verify that the all binary inputs
to the customer
terminal 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 (VS
P) inputs are 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.
• 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 the
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
engine board contains an adjustable digital amplifier,
, to compensate for long 10 Vdc cable runs. For
normalized (0–10 Vdc) signals, this setting should be
set 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.
UNT-SVX07_-EN.book Page 128 Friday, April 27, 2012 9:40 AM